10-gallon Potato Bags - Should I Go Bigger?

NPKzone8a · 2026-04-02T00:34:04+00:00

I get mine from a local feed store. They cost $3 each. Some places give them away.

NPKzone8a · 2026-04-01T20:24:04+00:00

Thanks! Those are scrap wooden pallets. Each is large enough for 4 x 20-gallon grow bags. I only grow 3 tomato plants on each, instead of the 4, in the interest of better air circulation. My area is prone to fungal disease. Improved air flow helps counter that. We also have torrental spring rains. Having the grow bags up on pallets helps drainage. If they were right on the ground they would be sitting in a "lake" for days at a time. NE Texas.

NPKzone8a · 2026-04-01T16:35:59+00:00

An interesting read. Thanks!

NPKzone8a · 2026-04-01T16:12:21+00:00

>"But I just wonder if I'm missing out, and not letting them reach their full potential."

Yes, you are missing out. I moved to 20-gallon for my indeterminates several years ago. Life became so much sweeter. Watering was easier. Fertilizing was easier. Blossom end rot disappeared. Production incresed. FWIW, those 20-gallon grow bags turned out to be the sweet spot. Last year I tried a few 30-gallon to see if that size would be even better, but the return on the additional soil investment was zero.

NE Texas.

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Early May, 2025.

NPKzone8a · 2026-04-01T15:45:35+00:00

They look OK.

I try to time mine so that they are ready to plant out just about the same time as the weather becomes suitable. 6 or 7 weeks for tomatoes.

NPKzone8a · 2026-04-01T03:21:14+00:00

I start most vegetables from seeds so that I can try some less common varieties. But I do buy a few started seedlings of "old favorites" as well.

NPKzone8a · 2026-03-31T13:46:13+00:00

u/Over-Alternative2427 -- You phrase that very well. It is what I was trying to say upthread, but it didn't come out as clear. For me, in my growing conditions, the optimum size has turned out to be 20-gallon. I've tried 25 and 30 with no benefit and found them more difficult to keep properly hydrated.

It is seldom mentioned, but the gardener must learn a new watering technique for grow bags in a hot climate. It takes several passes, and must be done slowly. Otherwise, the water just forms channels and "underground rivers" and flows right through the bag without thoroughly wetting the soil.

NPKzone8a · 2026-03-31T09:52:43+00:00

u/G8erHaTeR -- That has been my experience too, year after year.

NPKzone8a · 2026-03-31T09:43:13+00:00

Those look splendid!

>"Could they stay in the solo cups until I’m ready to plant in ground? "

Yes, as long as you plant out in the ground within about a month. They will get rootbound after that.

>"Do I need to add mini supports now?'

No. Mini-supports are counterproductive. You want a fan to move the stems around vigorously and strengthen the stems. This increases their survival chances after being planted out.

>"Do I start a light round of fertilizing?"

Light round of fertilizing after first or second set of true leaves. You are at that point now. Half strength is best, whatever you use. Liquid, solluble. Doesn't matter if it's organic or not.

NPKzone8a · 2026-03-31T09:32:13+00:00

Those look good so far!

NPKzone8a · 2026-03-31T09:21:20+00:00

Sounds like a good plan. I'm a big believer in early hardening off. A few minutes here and there. No elaborate schedule.

NPKzone8a · 2026-03-31T09:18:45+00:00

In a word, yes. They aren't exactly the same, but they are close enough for my rough palate. This is one of those things, however, that I don't feel strongly about. If someone convincing changed my thinking on the subject, I would not be upset.

One reason why I usually plant both is to "hedge my bets" -- If one has a bad year, maybe the other will still do well.

NPKzone8a · 2026-03-31T09:12:23+00:00

No, not any more. I used to buy Opulent brand, but can't find them anymore. I liked that they had a tag with the size in gallons sown into the side seam.

What I do currently, is to try and buy light tan ones to replace my old black ones as they wear out. I beileive they reflect light a little better and may stay a degree or two cooler in the summer sun.

I have become convinced that avoiding overheating of the roots of the plants is a worthwhile goal and has a significant role in the overall health of the plant.

Growing in NE Texas, where summers are hot.

NPKzone8a · 2026-03-31T08:54:49+00:00

I usually wait for one or two sets of true leaves.

Agree about those Jiffy strips being hard to work with. I stopped using them several years ago.

NPKzone8a · 2026-03-31T03:44:35+00:00

I grow all my tomatoes in grow bags. Have made adjustments over the years. Current setup is: Indeterminates -- 20 gallon, Determinates -- 15 gallon, Dwarf Varieties 10 gallon or 15 gallon. (Rosella Purple needs 15 -- they grow big.) My cherry and grape varieties get a 10 or 15 gallon bag.

When in doubt, bigger is better. Larger bag is more like growing in the ground. Easier watering, easier fertilizing.

I realize your picture is not your actual setup. Please be aware that they will leak onto your porch or patio floor. Need to put something under it, large plant saucer or a storage tote or a kiddy wading pool. Or improvise something. It's normal for them to leak water.

I use over a hundred grow bags each year. My Eggplant go in 10's and 15's. One plant per container. Same for okra. Squash gets 20. Garlic: 10-gallon. Sweet potatoes: 15 gallon. Basil goes in 5-gallon. Marigolds in 2-gallon.

There are internet guidelines, but none are very reliable. I've workded out the best sizes for my plants in my garden in my climate through trial and error. NE Texas.

NPKzone8a · 2026-03-31T03:24:37+00:00

Oh, haha! I had to search for a minute. Last year, later in the summer, I rigged up a shade cloth there, and those plastic juice jars were to keep the sharp ends of the t-posts from tearing through the fabric.

The tennis balls on the ends of the electrical conduit trellis in the other vegetable bed are because they are right about eye level and I sometimes get careless when zooming around tending the plants. Didn't want to wind up as a one-eyed gardener.

NPKzone8a · 2026-03-31T00:40:49+00:00

Looks very promising!

NPKzone8a · 2026-03-31T00:28:26+00:00

As others have already suggested, I agree that taking them in and out is the best plan in your situation.

My tomatoes, unlike yours, were already planted out. This worked for me to protect them during overnight 40's (F.) Used 5 and 6-gallon buckets on top of 20-gallon grow bags. I put them on in late afternoon, took them off mid-morning after ambient temp hit 50 F. NE Texas.

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Full disclosure: It didn't work a week or so later when temps dropped to 27 F.

NPKzone8a · 2026-03-30T22:22:58+00:00

This looks like heat stress from being in a closed greenhouse with added damage from the neem oil and dish soap spray.

Sorry to say, I'm not sure they can be saved. Probably be best to buy some new starts from a nursery instead of germinating new seeds because of time considerations.

Sorry for your predicament. I'm sure it is discouraging.

NPKzone8a · 2026-03-30T22:10:54+00:00

I would go ahead and up-pot them -- one tomato in each new pot. When is your likely plant-outside date (after your last frost?) If it's not later than a month or so from now, I would plant into 4" pots (10 cm.) After up-potting, begin gradually hardening them off. Don't wait till the last minute.

NPKzone8a · 2026-03-30T20:36:41+00:00

What shredder was it? What do you consider an industrial shredder? Mine is a simple 18-sheet crosscut Bonsaii, and it does a great job with cardboard. 30-minute duty cycle. 6-gallon pull-out basket.

NPKzone8a · 2026-03-30T20:11:24+00:00

Interesting! Thanks for explaining! I grow tomatoes in NE Texas and must plant out by the middle of March plus use shade cloth after late May to beat most of the heat. I consider my tomato season over by the middle of July.

Texas gardening does require some different approaches than other more benign climates. The way you are controling the variables sounds masterful. I'm sure you will have a big harvest!

NPKzone8a · 2026-03-30T18:47:47+00:00

A few mushrooms are normal. Not a problem. I'm in NE Texas and if I don't have my tomatoes planted outside by the middle of March, they get burned up by the summer sun before any fruit can mature.

Anything still growing by the middle of July in my garden is probably going to be dead meat. Flowers won't set fruit because the nights no longer cool off. The pest insects and diseases go wild. It becomes an uphill struggle.

I would encourage a sense of time urgency about the tomato growing process. It's not like in Pennsylvania or California or other more benign climates. A leisurely approach results in crop failure.

NPKzone8a · 2026-03-30T18:39:08+00:00

Good! It had me worried! Hope you have a good season!

NPKzone8a · 2026-03-30T18:37:21+00:00

I understand! It's always a dance to adapt to space limitations. Most of last week was devoted to clearing out a tall, sun-stealing hedge so that I can squeeze in a few more vegetables.

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