well I"ve got 4 barrels cut this way that I intend to use. But not below ground, I planned to just support them with something in front and behind each one so that they dont tip. I've considered a bunch of different things to put in them including new blueberry plants or I may end up putting strawberries in them. But when I first decided to use these barrels, I was thinking about anything could be planted in them, ie: herbs, greens, spinach, lettuce, carrots, beets, chard etc. any of which I think could easiy grow in them. they are plenty deep for most veggies. I'm still researching how well blueberries would do, they many not be quite deep enough for those. But I would also consider cutting bigger drain holes directly below the plants, so that deeper roots from the BB could go into the soil below if they so desired. The remaining soil could be controlled to provide the proper pH. And it gives them more surface area for roots than say a 1/2 whiskey barrel, which is another container I considered for them.

In a 5 gallon container you should not plant more than one of each, tomato, eggplant, cucumber, okra, pepper and squash. But you can plant maybe half a dozen beans. Actually, a 5 gal. is on the small side for tomatoes, unless it is a small DETERMINANT or dwarf type.

Nitsua, LOL! Yes, each time I saw this thread title that's what I thought, like one of those carnival games of counting how many gumballs were in the jar to win a prize. I didn't think to calculate either until Deeby asked for a formula to convert her pot size to gallons which is sort of the same thing. Deeby For a 20" top diameter pot, if you don't want to measure the height, bottom diameter and top diameter and get the exact gallons in the convenient online calculator, an estimate is that you have a sort of #20 or #25 pot, the height coming way up your thigh is quite tall. Most 20 inch pots are around 20 gallons, but the formula gives around 27 gallons since I guessed your "half way thigh high" is about 25 inches tall, but that was hard to work with since you could be wearing shoes, measuring the outer lip, or it could be sitting on a saucer, etc. Because pots have different slants from top to bottom, it isn't enough just to measure the top diameter. Yours sounds closest to the #25 tall here which is shorter but a little wider so around 25 gallons sounds reasonable. You can compare it to commercial pot sizes at nursery pots also to get a really good idea of the gallons: Nursery Pot Commercial Sizes The other way to do it is to see if the company/product number is on the bottom of the pot and see if their website has it listed in gallons too. Most do. Volume is what is important to roots, however you wish to measure it, since containers come in all shapes, as long as they are reasonable. PC

No one seems to have answers for you so I'll give you my thoughts. Container planting for veggies isn't one of my favs for suggestions, never had much success with that method other than possibly a small cherry tomato plant for minimum production. That being said, a max of one plant per 5 gal container is your best bet, I say this because later on when the pepper or sweet potato plant grow large it will keep you pretty busy watering the plants. Also black containers aren't the best color as they will get very hot in the summer sun and roast the roots on the inner wall, so it's best to shade the container portion. And 25 gal containers? would not like to move those when the time comes. Sorry for the dismal report, just too used to planting veggies in the ground where moisture, temperature, and daily attendance is less cumbersome (though weeding part is easier). Good luck!