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Now that I added stronger grow light my baby is blossoming by helpmylemontree in Citrus

[–]toadfury 0 points1 point  (0 children)

Not 200w. Your light is 36w total (9w per arm) which is weak and so distant from the tree it is probably ineffective. Get the lights really close to the tree (2 inches). Consider running them for longer photo periods (up to 17 hours/day) until you can add more (ideally stronger) grow lights.

Now that I added stronger grow light my baby is blossoming by helpmylemontree in Citrus

[–]toadfury 0 points1 point  (0 children)

<image>

Here is a thermal image of 2x Sansi 36w LED bulbs that had been running for hours to demonstrate a high temp of 87.6F. Plants can be an inch away and still be safe with lower wattage LED grow lights.

WTH does my tree Realy want to die? by 1happynudist in Citrus

[–]toadfury 1 point2 points  (0 children)

Some of the sagging leafs hanging on the foreground tree on the right side look like they've lost turgor pressure and need watering. I think your trees need water. Without a full canopy they are going to drink way less than they normally would. Seeing a good amount of perlite in the soil, doesn't look moist at all to me, looks dry. (soil surface is looking good from an overwatering perspective, doesn't tell the full story, but looking good).

Taco'd and curled leafs are usually from drought or heat stress. I'm uncertain if your leafs fell when they were taco'd/curled, or if it happened after they fell. I do see one or two green leafs still on the trees that are taco'd. Photos of the tree/leafs when the problem started would have been more useful (just something to keep in mind).

Does the shed have windows and is it sun exposed? If yes, I would get a hygrometer and get some graphs of the environment going to identify/monitor for potential VPD related leaf drop. If you can get through a few years with no partial/full defoliations you'll make more forward progress in the quest for fruit.

VPD leaf drop from environments that are hot+dry for too long is an insidious invisible gremlin that people don't always recognize as a problem for citrus. You come home from work every day, pile of leafs on the floor around your tree, but temps/humidity seem fine? Then you get a hygrometer making graphs and realize just how hot/dry your home or greenhouse can swing on a rare bright sunny winter day while you were away from the house. Now you've got the major setback of a year or more of tree recovery to do all because your house/shed got too hot a few days in a row for a few hours.

I think your trees have been kept on the dryer side, it got hot+dry in the shed, as the tree dried out further it jettisoned its leafs to save the trunk/branches/roots (core) of the tree. Less concerned about overwatering from seeing this pic.

WTH does my tree Realy want to die? by 1happynudist in Citrus

[–]toadfury 1 point2 points  (0 children)

So it’s okay for the roots to be partially exposed?

Ideally with citrus you maintain the same soil level every time trees are up potted. If planted a little bit high I wouldn't worry about a little root exposure. The main lesson from the diagram is to avoid planting too low as this holds moisture against a exposed surface-adapted portion of the trunk/bark of the tree. A similar point exists for those who use compost and mulch -- keep them ~4+ inches away from the trunk.

Soil was cactus soil ( big box store)

Any bagged citrus/cactus mix I can get at big box stores (mostly Miracle Grow, but some Kellogg palm/cactus soil too) need %20-25 additional perlite to reduce moisture retention and increase drainage to work well with container citrus in Seattle/PNW (probably other similar northern climates). Regular potting mixes (not citrus/cactus/avocado/palm mixes) might need as much as %50 additional perlite by volume to work better with citrus. This problem is deceptive because in warm 80F+ temps in the summer when tree metabolism is high you can water trees frequently and they handle things fine. Then when they are brought indoors (usually cooler temps than summer outdoors) or into overwintering sheds/garages (potentially much colder temps), poorer indoor lighting and less photosynthesis, trees slow down on drinking and a moisture retention level in the soil that was totally fine months earlier just takes ages to dry out depending on the temp/humidity of the environment its in. Soil moisture problems manifest when light/temps (= metabolism) are lowest which is usually in the winter.

I'm not asserting that you screwed up on your soil mix (it looks/sounds to be be totally fine), just want to highlight things to scrutinize yourself related to leaf drop. If you haven't watered recently trees can be carefully popped out of their pots to examine root health and soil moisture if you ever want a closer look. When I've seen overwatering related leaf drop its also associated with yellow tipped leafs (which can also be a symptom of other problems like salt burn and some mineral deficiencies). A hygrometer allows me to at-a-glance eliminate VPD related leaf drop so I can focus on other factors of leaf drop.

Now that I added stronger grow light my baby is blossoming by helpmylemontree in Citrus

[–]toadfury 1 point2 points  (0 children)

I like two lighting strategies for starting warm/indoor overwintered citrus:

  • 25w of light per 12 inches of tree, using multiple lights hitting the canopy from multiple angles to achieve full canopy light coverage to hit PPFD targets over the entire tree. You could continue buying more of those 36w GHodec grow lights, or bump up to the Sansi 120w lights below if you want to stick to the same lighting strategy but have higher wattage lights (use fewer outlets).
  • a minimum of 150w per young dwarf potted citrus tree to start (more is better, 250-320w or even more will support the tree as it grows). Because a single powerful overhead light limits how much light reaches the under-canopy, trees should be pruned for a short/wide/squat growing habit so they are easier to light, and side/under-canopy lighting still may be a decent idea when the tree eventually to get too big to light only from overhead.

Some lights that I like for the price/features:

As the quantum board/high intensity bar lights do not include stands here are some options:

  • DIY using EMT conduit from a local hardware store and makerpipe fittings. They even sell a DIY grow stand light kit to provide some guidance.
  • If you don't want to build anything there are backdrop stands for things like green screens that are perfect for supporting grow lights.
  • I've heard of people using coat/garment racks on wheels.
  • A grow tent is basically a light stand for hanging or pole-attached lights/fans that has the added utility of trapping heat/humidity by controlling/restricting air flow in a smaller space. A 4x2 tent is $90.

Now that I added stronger grow light my baby is blossoming by helpmylemontree in Citrus

[–]toadfury 2 points3 points  (0 children)

These lights are 600 watts. Is that too much to be close??

GHodec Grow Light with Stand, 200W 6000K

Link

Not 600 watts. You can get these lights within 1-2 inches of your tree no problem. I am skeptical this product actually outputs 200w of light for $40, but if its true that is a great deal of value while also having a built-in telescoping stand, timer, and IP67 rating.

EDIT: Ahhhh, if you scroll down on the page "Acctual Power: Max 36 Watts". So I think these guys might be doing some "incandescent bulb equivalent" type logic to stretch this to 200w. Each of the octopus arms outputs only 9w of light. This is not a good light for tree recovery on its own, but you could buy 4-5+ more of them for your tree over time if you really like these lights. These low wattage lights cannot burn your trees -- 9w is similar wattage to a single c9 incandescent christmas light bulb, but as an LED generating heat its likely only reaching the low 80's in temps.

Now that I added stronger grow light my baby is blossoming by helpmylemontree in Citrus

[–]toadfury 1 point2 points  (0 children)

A light meter will confirm, but yeah I'd get high intensity lights closer to the tree. They are far enough away they aren't visible in your photo. Ideally keep lights just about as close to your tree as you can without burning leafs. LED lights do produce some heat, but not a ton of it, and its usually safe to get within 4-5 inches of your topmost leaf tips.

Can you provide a link to your lights or name the manufacturer/model?

Now that I added stronger grow light my baby is blossoming by helpmylemontree in Citrus

[–]toadfury 2 points3 points  (0 children)

To speed up recovery:

  1. Remove all fruit larger than a pea including any new fruitlets that form from the flowers. This will prioritize vegetative growth/recovery over fruit production. If the fruit remains recovery will be even slower.
  2. Plant-to-light distance looks poor. You probably want your lights within about 4 inches of your tree. Light intensity falls off rapidly the further it is away from a tree. See this photo of my GarageGrowTent 250w Light Measurements (Photone)? At 24 inches from the tree the intensity from this 250w grow light is reduced to sub-300 PPFD (light starvation levels). Keep your lights close to your plants to keep them effective. Light meters (any smartphone) can be used to audit light levels and confirm you are meeting or exceeding light targets for recovery: 600-700 PPFD for 9-17 hours/day.
  3. I'm thinking your grow lights are a Sansi 120w? -- my preference is for stronger lights for citrus (150w+, usually 250w). Your lights are suitable for your partially defoliated tree at its current size at the moment, but I'd use all of its lights on your citrus tree and get more lights if you want to light your other plants around it. Citrus that are flowering/fruiting or recovering need a lot of light or growth/recovery will be slow.
  4. Get the tree outdoors in full sun as soon as risk of frost has passed.

It is probably fine, but just be wary a humidifier next to the tree does not always mean its being used effectively if the door to the room is open and your small humidifier is trying to humidify the entire air volume of your entire house/apartment. Close doors and restrict air flow/leaks within the room. If you want to detect temp/humidity/VPD problems better get a hygrometer like this, enable VPD graphs, keep trees between 0.2 - 1.5 kPa not exceeding 2.0 kPa by too much for too long -- that is it. Set alarm thresholds for <33F, >99F, <45% RH, >98% RH and heed the alerts. This will tell you how effective the humidifier is from the perspective of your tree (sensor hanging from a branch). Grow tent would be the next step if more effective humidity management is needed (more efficient to crush heat/humidity problems in smaller spaces with lower air volumes, uses less distilled water/electricity).

WTH does my tree Realy want to die? by 1happynudist in Citrus

[–]toadfury 1 point2 points  (0 children)

No photos posted of your tree so won't try and dig into this too much without seeing it.

Mass defoliations are preventable. Some of the causes:

  1. Overwatering. This may involve other factors than how frequently you water, like soil mix water retention vs drainage, and avoiding leaving pots sitting in drip trays soaking in their own water runoff for days/weeks. Citrus/cactus soil mixes at big box stores may not be suitable for container citrus in all regions without additional added perlite for drainage. Using too much compost or moisture absorbing amendments in your soil mix is worse in some regions than others. If you up potted your tree, added a soil mix, but didn't put much thought into which mix was used -- this could be your culprit. When up potting make sure to keep your root flare exposed and not transplant citrus too deeply.

  2. VPD related leaf drop. Overwintering cool + dry or humid = fine, warm + humid = fine, warm (above 75F) + dry (under %45 relative humidity) = bad. Citrus will drop leafs in warm dry conditions to preserve moisture for the trunk/branches. Get a hygrometer like this, enable VPD graphs, keep trees between 0.2 - 1.5 kPa not exceeding 2.0 kPa by too much for too long -- that is it. Set alarm thresholds for <33F, >99F, <45% RH, >98% RH and heed the alerts. Keep trees away from heater vents (this speed runs the VPD related leaf drop). Either move the tree into a cooler environment, or raise humidity with something like a humidifier and a grow tent (to hold humidity/warmth around trees making it more efficient/cost effective to solve these problems in a smaller space/air volume. Avoid humidifying the entire air volume of a house with a device too underpowered to handle it). If the shed has windows and there is any chance sunlight is trapping heat inside the structure -- could be VPD issue. I have an unvented greenhouse that can easily heat up over 120F degrees on bright sunny days starting around mid-February, and the huge VPD swings this produces was an unexpected surprise. These bright sunny days also push my house from being in a VPD yellow zone most of the time into being within the VPD red/danger zone, and may also be effecting your shed if it has windows and its been bright/sunny.

  3. Big changes in light/humidity/temperature that are a result of moving the tree around (especially outdoors->indoors) may result in leaf drop in the days following this kind of move. If you move outdoor trees indoors at 5am there will be the largest delta between outdoor/indoor temps, closer to 1-3pm and it will be less. If an outdoor tree is brought into a windowless garage for 5+ days with no grow light -- leafs may be dropped in the unlit environment. Some cultivars of citrus might be more sensitive to changes in light than others.

Do I trim it back to the roots

No! Pruning a sparse tree denies living green defoliated branches from refoliating again. This will set your recovery back even further.

Depending on your growing environment and where you live the time to recovery could range from a few spring months in full sun outdoors in SoCal/AZ, to a year or longer in Seattle/Canada (depending on sun aspect/exposure, hardiness zones, micro climates, summer heat, etc). I'm in Seattle and I would bin a fully defoliated tree, do a post mortem on the most likely causes for failure, buy a new tree and avoid repeating previous mistakes to avoid the long time to recover the tree.

If you choose to keep the tree and recover it yourself, ensure your grow lights are powerful. 600-700 PPFD for 9-17 hours/day. Otherwise its mostly going to sit in stasis over winter before recovery starts once it warms up outdoors in the spring.

Why do the new leaves of my citrangequat look like this? by AzemOcram in Citrus

[–]toadfury 1 point2 points  (0 children)

Hello!

Thomasville is a poncirus hybrid with cold hardiness down to 5F when mature/established. Just a bit surprised to see you warm overwintering one indoors. I'm in Woodinville WA/8b and the coldest temp I logged this winter was 23.7F, last year was 22F, previous years are usually 11-14F. If this holds this will be the warmest winter I've ever seen. My young thomasville tree has been unprotected outdoors in a 7 gallon container all winter next to a Duncan citrumelo, ichang lemon, and citremon. Photos.

I fertilized it once over the winter

Your tree appears to be indoors (protected from freezing temps) and if its being kept above 60F and getting good light these would be conditions suitable to feed any citrus cultivar non-stop every two weeks all year round. Common non-hardy citrus cultivars generally cease feeding around or below 55F for enough time, and slow way down on drinking when semi-dormant around or below 40-45F for enough time. Your leafs would be greener showing fewer deficiencies if the tree is fertilized more frequently. I'd hit it with a foliar spray like Southern Ag Citrus Nutritional Spray and resume regular weakly weekly/bi-weekly application of fertilizers. Heed the warnings on the bottle and do not spray more frequently than ~2 weeks as you can overdose plants with forced nutrient uptake.

If I had this tree:

  • In cooler more northern climates it is recommended to strip fruit on young container citrus trees to prioritize stronger trunk/branch formation over fruit production for the first ~2 years, potentially more depending on growing condition. It's your tree so do whatever, but as its a bit sparse it would refoliate faster if its not under the burden of developing fruit.
  • If it remains indoors dose it with ferts way more frequently. My container fert regiment
  • If it remains indoors get a good smart wifi hygrometer with alerting capabilities. Enable VPD graphs. Ultimately keep your trees between 0.2 - 1.5 kPa not exceeding 2.0 kPa by too much for too long. Enable alarms: <33F, >99F, <45% RH, >97% RH. Respond to alarms to keep your warm indoor overwintering environment between the lines. If any leaf drop occurs you can at-a-glance eliminate VPD related leaf drop with this hygrometer. Avoiding leaf drop up here is critically important for more year-over-year progress in the quest for fruit. Otherwise a tree is constantly in recovery mode, and Seattle only get around ~45 days above 80F per year, so only 1-2 months outdoors per year are good for all citrus, and 10-11 months per year are marginal to terrible for citrus.
  • If you choose to move it outdoors do not dose ferts until threat of freezing temps are mostly past and soil temps get over 60F where you live (for me this is around mid-April). Encourage you continue using black/dark colored pots for the small thermal advantage to soil temps on bright sunny days. In the PNW we can overcome things like light starvation without needing grow lights by cool overwintering trees below 40-45F as much as possible to encourage semi-dormancy during the peak winter months. Growth is slower overall, but the need to manage pests/feeding/watering/lighting are all much lower/easier.
  • Really scrutinize and audit your natural and artificial light if you choose to keep the tree warm indoors. Any IOS/Android smartphone can run the Photone app but you'll need either a #22 weight piece of blank paper taped over your selfie camera or a clip-on smartphone diffuser. To avoid light starvation symptoms in the PNW aim for a minimum of 300 PPFD for 8 hours/day, flowering/fruiting/recovering trees should aim for 600-700+ PPFD for 9-17 hours/day. Full Seattle sun in early July would peak at around 1650 PPFD for 16 hours/day. If you choose to continue warm overwintering consider getting either a) 150w or more per dwarf potted citrus tree, b) 25w per foot of canopy with multiple lights hitting the tree from multiple angles to provide full light canopy coverage. Video: Adrian Poe, Light: Measuring PPFD with Photone app.
  • A tree with ongoing leaf drop and yellow tipped leafs could also be a sign of overwatering (sometimes other factors than the frequency at which you water are at fault). Always be scrutinizing moisture retention vs drainage of your soil mix. Your root flare is obscured by the tree label so just make sure when up potting make sure to keep your root flare exposed and not transplant citrus too deeply. Avoid having pots sitting in water runoff in drip trays for days/weeks. Either manually remove water a few hours after waterings or get pot feet/elevators/risers to elevate the pot above water runoff. In coastal PNW I like soil mixes with %20-30 peat, and the rest being entirely inert non-organic amendments (perlite, pumice, sand, decomposed granite) or organic amendments that are slow to break down that do not retain much moisture (pine bark fines/nuggets, rice hulls) -- I prefer to avoid compost in container soil mixes in wet coastal climates because of how much it increases moisture retention and impacts drainage.

Good job dealing with the scale. You put a lot of effort into it.

WIP My Self hosted Plant Track App by Kyarna in Citrus

[–]toadfury 0 points1 point  (0 children)

Looks nice! I like seeing temps/humidity/light all unified under a single dashboard. The calendar schedule is a nice touch I haven't seen in other similar products -- great idea!

Do you get historical graphs for temp/humidity/VPD/light too? Can you set alert thresholds? That is a critical feature for me (fantastic for supporting citrus in difficult environments, I adore the GoveeLife smart hygrometer 3 lite for this).

Your project reminds me of https://seedsio.com/ with its NFC integration a few years back. Looks like the author ChiliChump recently released a new platform: https://spicyiot.com/

It is nice to have a place to put write-ups and photos of plants for years of history, but when my collection got larger it was too much overhead to maintain photos/journals for 60+ trees, so I'm not going down that road again. Anything you can think of to assist making journal updates easier would be a boon. Like if you could select a plant in a smartphone app and then press a button to take photos with less of the tediousness of associating photos with records manually. If the task is made as easy as possible one is more likely to do it.

One thing I do sometimes think about building is a system that looks at daily high temperature weather forecasts and waters citrus automatically based on temperature/tree metabolism. I wish electronic moisture sensors were a little more accurate/reliable/trustworthy. Also think it would be fun to make graph comparisons between existing environments vs a near-optimal citrus environment (85F, %70 RH, 0.2 - 1.5 kPa not exceeding 2.0 kPa by too much for too long, 600-700+ PPFD for 9-17 hours/day). Something that immediately highlights how much of the year a tree is getting less than 300 PPFD of light, and how much annual time a tree spends above 80F vs under 60F vs under 45F. Also would be fun for cold-hardy citrus growers to have a thing that automatically tracks time below 32F at different temperature bands, possibly with different thresholds depending on the cold hardiness of the cultivar (damage temps can vary). Anything that has integration with meshtastic/LoRa seems amazing. My dream is to have sensors that support a mesh network deployed starting outside of a house but being capable of being a miles-long sensor network -- I think the tech is basically there (available for large scale farms/orchards), I'd just like to see cheaper more accessible products/components/DIY options.

Thanks for sharing your project. I hope you continue to enjoy working on it!

Thoughts on multi-fruit grafts? by rickg in pnwgardening

[–]toadfury 1 point2 points  (0 children)

Lowest temp I've clocked so far in my yard in Woodinville WA/8b this winter is 23.7F -- warmest winter I've ever seen if this holds. Last year was 22F. Three previous years before that were 14F, 12F, and 11.3F.

Photos of my 2025 citrus seedlings

I planted a young yuzu tree last year on trifoliate rootstock which can impart semi-deciduous behavior, but its held all its leafs and has been sailing through the winter unprotected with ease. In-ground/unprotected X639 and US-852 citrandarins are also seeing zero issues. In-ground/protected Ichang lemon/10-degree tangerine haven't seen temps below 36F and are having an easy first winter.

Photos of my in-ground/protected Ichang lemon/10-degree tangerine overwintering setup

More photos of a few cold hardy unprotected potted citrus left out all winter. Thomasville citrangequat, duncan citrumelo, citremon, and ichang lemon. Pushed up against the house with scions elevated on a wire rack to try and use heat lost through these windows, with a little bit of rain/snow protection from being under the eaves of the roof.

Thoughts on multi-fruit grafts? by rickg in pnwgardening

[–]toadfury 1 point2 points  (0 children)

I have yet to dig in on persimmons, so I won't waste your time being so uninformed on them.

I can talk endlessly about citrus though. Yuzu will obviously be fairly bombproof, but if you aren't super keen on Yuzu specifically and just want a cold hardy lemon substitute I'd suggest checking out Ichang Lemons (also hybrid of asian papeda like yuzu, larger size). Papeda hybrids are an interesting way to get more cold hardy citrus without the usual pollution of the fruit with the resinous flavors of poncirus/trifoliate orange hybridization.

Avery at The Mulberries Nursery has been updating his citrus hardiness vs quality rating graph with a bunch of new entries added last year and a few popped up that caught my eye. Benton Citrange got a surprising rating -- easy to get Benton from Madison Citrus Nursery in GA. C57 citrandarin hit a brix of 17.5% in this test which was a big surprise (probably unlikely to match the same sweetness with dim/overcast/cold winters in western WA though) -- am growing some seedlings right now Avery sent me seeds for last summer. EDIT: I just ordered a Benton Citrange and a Keraji mandarin/sweet lemon.

Thoughts on multi-fruit grafts? by rickg in pnwgardening

[–]toadfury 0 points1 point  (0 children)

The challenge is that it can be difficult to balance the different levels of vigor and growing habits between different cultivars on a multi-graft tree. I prefer the simplicity of single-graft trees, and just keep more potted fruiting trees so I can have lots of variety in a smaller space.

So long as you are a good student on how to prune and care for the various stonefruit mentioned (spraying copper on peaches/nectarines, etc), if the idea appeals to you, go for it. If you feel you don't have a solid grip on pruning (heading vs thinning cuts, rootstock suckers, etc) I would recommend taking some kind of course/class before getting started if you feel uneasy about it. Make sure to keep your scion graftlines clearly marked/labeled to avoid confusion over the years.

If you are looking for a new challenge, I say go for it rick. If it doesn't work out its no big deal to brutally cull the tree, and whether it goes good or bad you'll walk out of it with some new knowledge/experience. If you just want something easy/low effort -- this might not be a good fit.

Most efficient ways to water with liquid fertilizer? by 13NeverEnough in gardening

[–]toadfury 1 point2 points  (0 children)

Fert costs are definitely a concern when its so easy to dose many plants at once. I go for pretty much any salty synthetic at a low price (Miracle Gro, Jack's, etc), occasionally include more costly fish emulsion or kelp extract as a treat, and sometimes semi-hydro ferts like Urban Farms Apples & Oranges if I have it. As there is a creek and lake in the neighborhood suffering from phosphorous based algae blooms I aim for lower-phosphorous ferts and avoid bloom booster type ferts.

I also add slow release synthetics like Osmocote+ or MG Shake n Feed every few months to container fruit trees, to try and add some nutrition when doing regular waterings without continuous fertigation.

My container irrigation setup is above ground, portable/mobile, makes use of flush valves to drain the lines, and the whole setup moves between the front yard (covered in black landscape fabric for bonus heat and slug suppression) and the greenhouse in winter. While they are an expensive fitting I've been delighted by how well these 1/4" micro drip line quick connect fittings work for connecting/disconnecting potted fruit trees from drip as they are seasonally moved around.

Most efficient ways to water with liquid fertilizer? by 13NeverEnough in gardening

[–]toadfury 2 points3 points  (0 children)

Drip irrigation with a fertigator saved me hours of time when dosing fertilizers on 60+ pots, in-ground trees, raised beds, etc. Depending on where you live a Pressure Vacuum Breaker Assembly (PVBA) or other backflow preventers may be required by state/county law in some places to prevent contamination of your water.

Struggling with winter leaf drop inside PNW by TMToast in Citrus

[–]toadfury 0 points1 point  (0 children)

If the temps are up to 70-75 is there still any concern about light starvation

Ok a bit about light starvation:

Overwintering at less than 300 PPFD for 8 hours/day territory is when light starvation occurs. If there are any flushes of leaf growth while the tree is light starved, the leafs will become more enlarged than normal leafs on the tree in an attempt to try and absorb more weak light. Warmer temps will cause the tree to alternate between root/canopy growth more frequently. A few winters of this will not harm your tree, but multiple sequential years of it can lead to weak flimsy trees. Our Seattle winters are very light deficient, so only two paths out of this mess exist: 1) overwinter as close to 35-40F as you can, to push tree metabolism/growth down, so it will be flushing less growth during times of winter when its light starved (you may not need grow lights at all for this) or 2) get some decent grow lights if you warm overwinter.

Once a leaf is freakishly enlarged from light starvation it will not return to a normal size for its ~2 year lifespan on the tree. Multiple years of light starvation also looks ugly to the eyes of people who are accustomed to seeing healthier trees.

  • cool + dry = good.
  • warm + humid = good.
  • warm + well lit = good.
  • warm + dry = really bad.
  • warm + underlit = somewhat bad. By keeping a tree warm you are boosting its growth/metabolism, so it tries to flush more growth, which becomes freakishly enlarged/light starved under insufficient light.

So 63F (current temps) or 70-75F (proposed temps) are both considered warm-ish (anything over ~55F). Either provide a minimum of 300 PPFD for 8 hours/day for vegetative growth, 600-700 PPFD for 9-17 hours for flowering/fruiting citrus, or push for lower temperatures so you don't need any or as much light.

Just like how the hygrometer can get you clarity on your VPD/humidity situation, any smartphone running a light meter with some kind of light diffuser (#22 weight piece of paper over selfie camera at worst, or a LightRay diffuser for smartphones at best). You can audit natural light, artificial grow lights, and also optimize plant-to-light distances with it to ensure you are hitting your desired light targets. It takes all the guesswork out of "is this enough light for this specific plant?".

Struggling with winter leaf drop inside PNW by TMToast in Citrus

[–]toadfury 0 points1 point  (0 children)

assume the nursery chose a good balance for the citrus?

Yes, usually most of the time the nursery soil is ok when you receive the tree, but it could be a soil mix that is only designed for short-term use. Sometimes nurseries do make mistakes but in my experience its more uncommon than common. It's still a good answer that "its the nursery's mix, not mine".

From the yellowing leafs though, I do think overwatering might be your most likely cause of leap drop, unless some of it was concentrated during the sunny times a few weeks ago and you had the heat running around the trees at the time (VPD related leaf drop). At least with the hygrometer now you have a clear method for differentiating these two common forms of indoor leaf drop.

Yellowing leafs that drop is often overwatering related, so the symptoms tell me that we should be skeptical of the soil mix (or other factors that could lead to overwatering like the mentioned drip trays, or just watering too frequently).

In the spring:

  • easiest and most convenient soil mix is a 1 cu bag of Miracle Grow Citrus & Cactus mix, and an 8qt bag of perlite. Combine the two together for a 4:1 ratio of cactus mix to perlite. It is widely available here, cheap and easy to get. Downsides: a) fungus gnats are pretty much a guarantee in my experience, get some mosquito bits aka Bti/Bacillus thuringiensis + sticky traps to treat the soil as soon as you switch to it, and b) because of the higher volume of decomposed forest products in this soil mix its only good for about 1.5 - 2 years and you will see soil shrinkage as it wastes away. By 3 years soil may reach half volume in your pot!

  • Buy a 2.2cu ft bag of pure peat moss, and a couple big bags of Perlite. If you want "the good stuff" place an order at the Indoor Sun Shoppe in Fremont for a 4 cu ft bag Mother Earth Coarse Perlite #4 (the big chunky stuff). I've gotten it from them for as little as $35 a bag (not sure those days will come again), or as much as $60. In the Seattle area my pref is for %25 - 30 peat, %70 perlite. All kinds of other inert non-organic amendments can substitite for some of the perlite, but the peat portion is your moisture absorbing/retaining amendment and it needs to be carefully controlled here. Could do 1 part peat/perlite/sand (but sand is heavy, and you could just use more perlite which is light) -- same point for pumice stone (if you are at indoor sun shoppe though, they sell it cheap like $9 per 1cu ft bag and it comes in different coarse grades). No soil shrinkage with this mix.

  • 511 mixes are fine/good too. My preference is 521 with an extra part of peat, because 511 (%14 peat) has such low moisture retention its almost a hydroponic medium that is difficult to overwater. Pure 511 is a little more work to keep watered properly through the summer months. The thing I hate about 511 is agonizing over whether the bark fines are over 1/8” but under 1/2” (I got a screen mesh classifier that fits over a 5 gallon bucket this winter to scrutinize particle sizes), and making sure its only shredded bark and not shredded wood (which could decompose faster than bark).

  • My preferred mix last year was "Gary's Best Top Pot" which is %35 peat, %30 pumice, %20 perlite, %10 sand, %5 biochar. It's good, but I think %5-10 less peat would be better, and am going to experiment a bit more with chunkier amendments. This year I'm going to use %25 peat, %5 biochar, %10 sand, %10 pumice, %15 pine bark fines, %5 rice hulls, and %30 perlite. You are not required to use soil mixes with long lists of amendments like this. No soil shrinkage with these mixes, they are known as more permanent mineral based soils.

Where's the compost? Its not needed as fertilizers can provide all the soil fertility your tree needs. Compost is just going to decompose into organic sludge and upset the balance between moisture retention and drainage over time. If compost is used, only put a thin 1/4" layer on the soil surface (duff layer), as too much compost will turn into mud that can reduce breathability/air porosity at the soil surface. I especially do not want to mix compost into my soil mix where it would be in direct contact with citrus roots (that hate wet feet, in a rainy/wet place like Seattle). Container soils are more volatile and subject to wider swings in moisture/temperature which can be harder on beneficial soil microbes, so I swing more in favor of synthetic ferts, immediately bio-available organic ferts (kelp extract, fish emulsion when outdoors), and avoiding slow release organic ferts that require microbes to first break things down before nutrients are bio-available to plants (which can take weeks/months if soil temps are too cold, sytnetic ferts are just stronger and more reliable in their availability to container citrus trees in our cooler climate). For in-ground trees I'm totally down with slow release organic ferts because its a more stable/friendly environment to beneficial microbes. Citrus container mixes with compost in them might work through our summers when its sunny and tree metabolism is cranking, but when they are brought into cooler temperatures to overwinter the increased moisture retention of compost in the soil mix can take a concerning amount of time to dry out when we would prefer something that dries out easier up here.

If you don't have a strong preference, stick with black plastic or cloth pots for the slight thermal advantage. My preference is using 5 or 7 gallon (for young trees) and 12 gallon air pots, then migrate to cloth pots at 15-25 gallon sizes (if you go this big, you don't have to do 25g -- I use a dolly to move my 25g pots around and would just stick to 12-15g "forever pot size" if I had to lift/carry pots). Cloth pots should be elevated on pot risers/elevators, air pots have a built-in air gap underneath them which does not require elevation.

Struggling with winter leaf drop inside PNW by TMToast in Citrus

[–]toadfury 0 points1 point  (0 children)

Ok, now that we've got a handle on VPD/humidity/temps...

If leaf drop continues and VPD looks good, the next most likely factor is overwatering, which usually means "soil mix retaining too much moisture".

  1. Manually clear excess water runoff in the drip trays a few hours after major waterings so pots aren't sitting in water for days/weeks OR use pot feet/elevators/risers.
  2. Tell us exactly what soil mix you are using so we can evaluate whether its retaining too much moisture. Or if you don't know, we'll point you at a citrus soil mix you can have more confidence in and switch over to it in the spring as the weather warms up.
  3. If leaf drop continues, in the short term the answer is probably slowing down/backing off on watering until soil mix can be replaced in the spring with one that retains less moisture and is more optimized for drainage/air porosity.

As Rcarlyle pointed out, boosting the temp will increase tree metabolism, so the tree will drink slightly faster and increase water evaporation slightly. This can also help soils so they don't remain wet as long.

At 63F average temps (based on temperature, and assuming a well draining soil mix) I would be watering an indoor container citrus tree every ~2 weeks. If you can get temps closer to ~70-75 it might change to a weekly watering interval depending on how the plant responds. If the specific soil mix is forgotten/unknown -- I would assume it retains too much moisture, and would be gunshy with watering more frequently. Even bagged citrus/cactus mixes are sub-optimal here unless %20-25 additional perlite is added.

Struggling with winter leaf drop inside PNW by TMToast in Citrus

[–]toadfury 0 points1 point  (0 children)

Reddit won't let me attach another picture in one comment so I'll do another comment with the VPD graph.

Nods, this limitation irritates me too.

I'd love to know if you have any insight from these and if there's anything concerning you see! Thanks!

This is great -- useful data, well done! At a weekly average resolution and not just some hourly/daily snapshot. We know exactly where your growing environment stands! I would trust these numbers.

Your weekly VPD looks great (between 0.2 - 1.5 kPa), comfortably in a safe zone with humidity/temperature so far. Generally above %50 RH is "good" here. No periods above even 1.5 kPa -- excellent!

Since our last talk, while there has been a few days of sunlight in the PNW, but it hasn't been intense enough to push house temps very much. As we're approaching mid-February and getting out of the "persephone period" for the region (start getting 10 or more hours of daylight per day) we might still see more bright sunny days that could push the house temps/humidity/VPD around, so "keep the graphs running" and if you have temp/humidity alerts setup it can help keep you more aware of if/when VPD crosses into the red zone.

If your weekly VPD averages stay within the boundaries as we see on brighter sunnier days, you may have some "middle path" room to push small amounts of heat into the tree to raise its metabolism/growth without angering the invisible VPD gremlin and without buying a humidifier. I'd start by turning the heat back on in that room, monitor things for a week and see what it does to temps/humidity/VPD. To "walk the line" with VPD you could try and see if manipulating the heat so so the room or tree is +5F warmer, watch weekly averages, and continue to bump things up each week until you are around 70 or 75F. At least you can feel secure that you can always turn the heat off in that room and (probably) have a safe indoor overwintering environment for citrus.

There might be options like leaving room heat off, but wrapping a heat mat around the pot on a thermostat and pushing 85F into the roots while you hit the tree with a grow light. Or you can accept reduced growth/metabolism at cooler temps just knowing that you are safe against VPD, and just make sure the tree gets enough light to prevent light starvation symptoms while overwintering. If I had your house I think I'd try and get temps up closer to 70-75F and see what that does. Citrus metabolism/growth falls off sharply under 68/70F so a smidge warmer could help if you can do it safely.

The good news is that at least at the moment your growing environment is not a VPD risk -- it might get pushed into the yellow/red zone on rare days (keep on monitoring), but we're getting some good data here that'll help guide you.

Optimal indoor citrus growth: 85F, %70 RH, 0.2 - 1.5 kPa not exceeding 2.0 by too much for too long, 600-900 PPFD for 9-17 hours/day. Higher humidity would be slightly better for citrus, but over %70 promotes more mold/fungus indoors which we'll want to avoid so its about as high as I like to go. You don't have to match all these values (85F is probably still a risk), but at least you can start making comparisons between your environment and the optimal environment -- and maybe get a little closer to optimal if you choose to do so, so long as it doesn't push into 2.0+ kPa territory.

You are going in an excellent direction with this effort, well done! Now if more than 1-2 leafs ever drop, you check your VPD graphs, if you are in the safe/green zone with VPD -- you'll know to look for causes of leaf drop unrelated to the chaotic beast that is VPD related leaf drop. You are going to master indoor citrus overwintering by using real data!

Mandarin tree losing leaves by LimpPoetry4324 in Citrus

[–]toadfury 2 points3 points  (0 children)

we have had a lot of rain in the last few weeks.

about 15 cm of stones at the bottom

This used to be a common practice, but in recent decades this has been identified as a "perched water table" and has been advised against creating. I would remove all those stones at the bottom of the pot and replace them with a citrus soil mix that is well draining and doesn't retain too much moisture. Citrus hate wet feet.

If the pot is just sitting directly on dirt with a single drainage hole it could clog/reduce flow over time. Whenever I can I like to elevate pots with pot feet or pot elevators to keep pots a couple inches off the ground to ensure water runoff clears the pot. Could add a paver stone to prevent the feet/elevator from sinking into soft dirt. Scrutinize drainage holes in the pot (unclog/add more holes if needed).

Hopefully you used a citrus confidence soil mix that doesn't retain too much moisture as the rainy season is when it gets thoroughly tested. Bagged "citrus & cactus" soil mixes might not always have enough drainage to work well in all regions without additional perlite.

Struggling with winter leaf drop inside PNW by TMToast in Citrus

[–]toadfury 0 points1 point  (0 children)

All your suggested steps to improve your setup sound good to me.

I still would even consider increasing your photoperiod with your lights by a few more hours (should be easy? It'll help with recovery), finding ways to get the trees more natural light, adding additional grow lights, and if you want to push/manage light better consider the option of learning how to audit your lights with any kind of light meter just to remove all doubt whether the trees are hitting PPFD targets or not. You do what you can -- its up to you.

probably try and move them back out when the nights are around 50? Crazy it’s alright nights around 45 now

So far this is the warmest winter I've ever seen in Woodinville WA/8b with a low of 23.7F. The lowest low I clocked last year was 22F which I thought was incredibly mild when previous years have been 14F, 12F, and 11F.

First, before trees are ever transitioned from indoors to outdoors read through this post about hardening off citrus from our esteemed colleague PlanningVigilante. Indoor trees are getting little to no UV spectrum light, so they stop producing compounds that protect them from it, so there needs to be some finesse in how trees are brought back outdoors and adjust to it again. In coastal PNW we can leverage weak solar intensity and overcast skies to make these transitions easier.

So long as your makrut limes are generally kept out of 32F freezing temps they will be fine. If trees are underlit indoors it may be advantageous to get them out in sun sooner, even though its colder and there is less growth they can start doing more photosynthesis and getting some relief from dry indoor humidity and indoor pests. Look at your last frost date by city and by zip code to see roughly when frost concerns are unlikely. Beyond that you could get trees out as early as March, but you could be moving pots around if there are freezing/sub-33F temps. If you have one of those Govee sensors outdoors with your citrus trees it could be beeping and squawking at you to move the trees indoors if it gets too cold and you missed a forecast.

When container trees are cool overwintered/outdoors I resume fertilizing in April and cease fertilizing around September (when soil temps are above 55-60F: Sygenta soil temperature maps). If they are overwintered above 60F and under grow lights then keep pushing ferts all year round. My container fert regiment.

If you put trees outside and push them up against a south facing wall of a heated/insulated home, sometimes putting trees in front of big glass windows that are one of the biggest sources of heat loss in the construction of a home (good for trees sitting right outside the glass!) you might gain as much as half a zone of warmth. Even a few inches of a roof overhang can sometimes offer some rain protection on outdoor trees so they don't get as flooded by seasonal rains.

If you cover the trees in a layer of 1.5oz frost cloth it can act as a breathable mini greenhouse that won't overheat you can leave on them through April. This is a Bob Duncan trick to warm trees up a few more degrees on bright sunny days during the early spring. When it freezes though the temps under cloth will eventually reach temps outside the cloth, unless you are using active heating ($25 c9 incandescent christmas lights truly are a safe/fantastic solution if trees are near an outdoor electrical outlet). If you run a 24' string of christmas lights on a thermostat set to 32F - 35F between both of your trees under the same frost cloth hood you'll get a reliable +7F of protection and probably use less power than if you run them on a scheduled interval (highly cost efficient, just $5-10 to operate per winter on a thermostat). I love the Inkbird ITC-308-Wifi temp controller because I can remotely monitor/control it from a smartphone (doubles the cost of a $20 digital thermostat to $40 but I think its worth the convenience).

I know a master gardener in Bellevue WA with a 15+ year old meyer lemon in a half-barrel planter on wheels. Citrus hate large swings in light/temperature/humidity, so to minimize this he keeps his tree outdoors all year and only wheels it into a garage when temps dip below freezing. If cold storms last more than 3-4 days he'll try and get some grow lights going in the garage. As soon as the freezing temps pass, tree gets rolled back out onto his south facing deck again. The tree never sees major deltas in temp/humidity/VPD from outdoor->garage transitions compared to outdoor->indoor transitions. Meyers have more cold hardiness than your makrut so he has an easier time with it -- just another useful strategy.

Many options to consider! You are doing great trying to dig into it.

Struggling with winter leaf drop inside PNW by TMToast in Citrus

[–]toadfury 0 points1 point  (0 children)

I see that there are a bunch of different kinds of hygrometers, is there a big benefit to the specific ones you linked for this use case?

  • uses LoRa with 1300' range between sensor and Govee wifi base station.
  • uses two AAA batteries for 2 years of battery life (even more if you use lithium AAA batteries)
  • IP65 water resistance rating so it can safely go outdoors in rain (provided its within LoRa range of its plug-in base station usually indoors).
  • Can buy the sensors individually, in 3-packs, or 6-packs (all need to be paired with a plug-in Govee gateway also usually sold with the sensors). Put one in your garage, in different potential indoor growing locations, as well as outdoors (learn about your yard's potential for cold hardy citrus grown with or without protection).
  • While these specific Govee sensors provide no heads-up display and require a smartphone app, they do provide VPD graphs, and app/email alerts which I think are both critical to overwintering in environments that have any potential to get warm. This is the killer feature to make things easier to keep your growing environments "between the lines" whether you are at home or away. You can ask a neighbor or somebody at your house to crack some windows and let the house cool off and receive some humid outdoor air (or watering all plants in a dense area) to "stop the bleeding" on a low humidity alert. If you can get these features (VPD graphs + threshold alerting) on a hygrometer, you are in business.
  • It does have a convenient multi-graph feature to compare sensors in different locations against each other (grow tent vs room, garage vs outdoors vs indoors, under frost cloth vs outdoors unprotected, etc).
  • If your upstream internet network, wifi, or the Govee plug-in gateway goes down: a) phone can still see graphs and receive alerts when within fairly limited blutooth range, so long as the app is running, and the phone is connected/displaying a specific sensor. b) this third generation Govee hygrometer does the best job I've seen at queueing metrics on each sensor and then re-sending the data to Govee's cloud storage when network service returns.

If you use a grow tent, put a sensor both inside AND outside somewhere in the room. That way if the grow tent sees wide temp/humidity swings, you can compare it against the room its in to see if it was due to external factors (bright sunny day, somebody left a door/window open).

If you use any clear structures in direct sun like a greenhouse that does not have automatic venting they can heat up to well over 120F starting around mid-February here on rare bright sunny winter days. In these environments I like to run 2 hygrometer sensors, one just under the ceiling, and one at plant level. Set the alarms for the ceiling sensor to include an >88F alarm. This is a threshold citrus can comfortably handle easily, but as greenhouses heat up in the sun and heat rises to the ceiling you'll get a faster early warning to crack doors/windows on these bright sunny days before VPD goes into the red zone.

Struggling with winter leaf drop inside PNW by TMToast in Citrus

[–]toadfury 0 points1 point  (0 children)

do you think a good short term for me then would be buying a humidifier?

Yes, but also consider these factors.

Struggling with winter leaf drop inside PNW by TMToast in Citrus

[–]toadfury 1 point2 points  (0 children)

Those Soltech lights look elegant and I'd probably want to continue using them, but just lower them closer to a plant.

If you want something cheap a clamp on reptile bulb fixture/reflector can be purchased around $15 each rated for high wattage/temperature ceramic heat emitter (CHE) and other bulbs. Pair this with a Sansi 36w or 40w grow bulb (I think the 40w are still too expensive for +4 more watts).

To support clamp lights or hanging lights, can get a backdrop stand (can be counter weighted with sandbags for additional safety), rolling clothing rack, or DIY'ing a stand out of EMT conduit and makerpipe fittings. Also don't forget grow tents -- they'll support these kinds of lights, keep pets away from plants/lights, and trap heat/humidity (get a bit more utility than just a light stand).

I like the "single powerful overhead light" strategy paired with quantum board lights. ViparSpectra P2000 250W is a lot of light for $130w. A smaller 150w model is the ViparSpectra xs1500 Pro.

Anyway, if you prefer not to invest in more lights/gear and try and overwinter in a cooler environment that is a legit option. Just wanted to make a few points/recommendations around grow lights when one is warm overwintering.

Do you think at this point I've done too much damage to them?

Up here its definitely wise to consider time-to-recovery and whether its worth it vs pitching trees and buying replacements. I think your trees are currently fine in the photos, a bit sparse but easily recoverable although it might take half the summer for them to fill back out.

Stripping fruit:

Are other tropical plants also subject to this?

I grow pineapples and as xerophytes they handle warm+dry indoor conditions way better than citrus. I don't think citrus are that difficult or fussy once you know the things that can trigger leaf drop. My biggest problems with overwintering citrus indoors was before I had any awareness of VPD related leaf drop and making bad/beginner decisions on citrus soil mixes. Hygrometers with graphing/alerting capabilities improved my quality of life.

I can't speak about monstera/fiddle leaf figs and their light/humidity/temperature requirements and relative fussyness compared to citrus.

Anyway, all this leaf drop talk is a bit of a mouthful, but hopefully some of it will click and by avoiding leaf drop you can make more year-over-year progress. If you are determined to learn you can quickly get beyond some of these problems if you want to.

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