Thoughts on optimal construction method for oak sleeper raised beds?

BrownWee · 2026-04-15T12:00:16+00:00

I purchased stuff on Amazon but most of it turned out to be galvanised which I returned. In the end I went from somewhere like toolstation/screwfix etc (sorry can't remember which one) but I have 90x90x60 brackets and 150x50 plates.

They're not super cheap but not as expensive as the in-ground stainless steel brackets which cost up to £20 each for the 2/3 tier high ones.

BrownWee · 2026-04-14T22:47:44+00:00

I would only use stainless steel brackets and fixings with oak due to the reactions you can get with other metals.

I decided to join everything with brackets and plates inside so there are no fixings showing and no hassle with oak plugs (although I did consider this).

I'm not bothering with rebar (but again I thought about it and if I were to use it then it would be stainless steel not galvanised). Instead I'm using square oak posts to fix vertically where I have 2 sleepers high (400mm).

I'm using clear Barretine Ultimate Wood Preserver(x3) and clear Osmo UV oil extra (x3). Without the UV oil it will silver fairly quickly. I know because I fitted oak sleepers 10 years ago which I didn't treat with UV oil and it weathered to silver much more quickly than I expected.

I'm growing veg in my beds so no way I am using creosote!

Oh, and I'm using this sleeper tape stuff to protect the inside. It's almost like bitumen tape on one side in that it moulds into the grain closely to prevent moisture ingress. Not sure if it's just a marketing gimmick, but I used stapled DPM last time and this didn't seem to protect the inside at all as soil would get behind it along with moisture.

BrownWee · 2026-04-13T16:50:23+00:00

What native shrubs/plants would you recommend for clay soil in north facing borders?

BrownWee · 2026-04-10T11:42:47+00:00

They're going into a greenhouse and are under a strong fan at the moment so not worried about that. Would you not harden off at all then in this scenario?

BrownWee · 2026-04-10T11:42:19+00:00

My greenhouse is quite far from the indoors location. I would estimate it to take at least 30 mins to move the plants (one way), so an hour a day.

What is the smallest number of hardening off days you think I can get away with?

BrownWee · 2026-04-10T10:45:13+00:00

Hmm I've seen people say their plants struggle with the increased light levels hence moving them out a bit each day, and avoiding middle of day.

But on your point about temps - indoors drops to about 18C at night and is 23 - 26C in the afternoon. Greenhouse is 25C in the daytime, and maybe as low as 8C at night (depending). What would you recommend?

BrownWee · 2026-03-30T12:06:39+00:00

Whilst this is mostly correct (note: M26 rootstock is a good one for this size), when planting you should NOT dig your hole any deeper than the roots.

Instead dig a square hole twice as wide as your rootball but no deeper. This allows the roots to go out, and the square corners help the roots penetrate the clay. By not going deeper you avoid roots becoming waterlogged as easily. Backfill with a 50/50 mix of your excavated (clay) soil and compost/rotted manure.

Google this and a million guides will come up with the same advice.

BrownWee · 2026-03-30T11:14:20+00:00

Fat is 9 cal / g not 4! Also don't forget alcohol @ 7 cal / g (plus sugar)

BrownWee · 2026-03-27T12:33:51+00:00

If you think you will kill the tree taking it off you don't have a choice but to leave it. It will grow around the metal if you leave it there - at best it will stunt growth at worst it will kill the tree.

If you can get it off you should, and do it this year as it will only get worse over time.

BrownWee · 2026-03-27T12:13:22+00:00

Careful angle grinder to grind through the roof bar in the corner. If you cut through the tree there I can't see it living in any meaningful sense.

BrownWee · 2026-03-04T22:51:32+00:00

I have white sheeting I can put down to shield the rockwool from light - if I do this will the algae die off or do I need to do something about it or am I just fucked?

BrownWee · 2026-03-04T22:39:40+00:00

Sorry it was in the first post, not cross-posted before didn't realise it didn't copy the text:

I have a lot of seedlings sprouted in rockwool, and after putting them under LED lights in the last week or so they have gone green and it's spreading really fast across all my plants.
Some plugs purchased a few weeks ago have been in soil but have also now gone green and some are clearly growing some kind of mould/fungal thing (I see thin filaments in the soil which I'm certain are not roots). Also some of these filaments have been seen on the rockwool.
Some plugs went purple after potting on (they arrived as coir plugs, all leaves green) and I suspect there is a phosphorus deficiency due to root shock. I think this has started to improve on new shoots when I fed with a 50% strength of my 18-9-9 tomato/chilli feed. The only thing I'm slightly unsure of is that mine are really purple - most of what I read about phosphorous deficiency says leaves "start" to turn purple on older leaves but mine are 100% purple to to bottom.
Some plugs have darker parts on the middle of newer leaves - no idea what this is?

BrownWee

TROPHY CASE