I've been growing regular tomatoes in 15 gallon nursery pots. In addition to these, this year I'm trying some dwarfs since I've never tried any of them before:

Adelaide Festival
EM-Champion
Pink Passion
Rosella Crimson
Rosella Purple
Sleeping lady
Sweet Scarlet

I'm thinking these would do OK in 7 gallon pots or can I go smaller, like 5 gallon pots?

I do 5 gallon and they do great. But by later summer their roots occupy the entire bucket and need daily watering. You have hotter summers than I, so I’d lean 7 gallon. But maybe do both and see how they differ?

Zone 6
I use 5 gallon buckets, but in a self-irrigating design. Basically two 5g buckets stacked - top one with potting mix, net cup in the bottom center and the bottom bucket is a water reservoir (about 6" of space between top and bottom bucket). The dwarf tomatoes appeared to grow really well for me. Most were not overly productive, but I assumed that was just normal for dwarf tomatoes. However, I have nothing to compare to.

I will be growing 8 more the same way this season.

As mentioned, I think it just comes down to how often you will need to water them in your climate.

Basically, the smaller the pot gets, the more important it is to apply fertilizer with each watering. You can grow a tree sized plant in a 6" Rockwool cube, but it has to be on a nearly constant drip of strong fertilizer. So your answer depends on how you fertilize and water.

I've always used 5 gallon pots for dwarf tomatoes.

I grew EM Champion in both 5 and 7.5 gallon containers last year. The 7.5 was definitely better for them. I can only speak for the first half of the year, since we had a problem halfway through the summer and lost our containers. But they did great up to that point and I really liked the tomatoes I was able to get from them. They do need support even more than the average dwarf ime.

Acer Rubrum wrote: ↑Tue Apr 05, 2022 9:47 pm I grew EM Champion in both 5 and 7.5 gallon containers last year. The 7.5 was definitely better for them. I can only speak for the first half of the year, since we had a problem halfway through the summer and lost our containers. But they did great up to that point and I really liked the tomatoes I was able to get from them. They do need support even more than the average dwarf ime.

EM Champion was a bit of a sprawler for me last year. Definitely needed more support than the Dwarves I've grown (Rosella Purple, Tasmanian Chocolate).

I grow dwarf tomatoes in a 5 gallon bucket. For the little micro tomatoes I used a 2 gallon bucket. it has worked well for me. HTH

I appreciate all the advice! There will be cages available to slip over the dwarf plantings. The 5 gallon pots I have are nursery pots (as are all of my pots), not 5 gallon paint-type buckets from Walmart or H. Depot. I think there's a difference in volume but I'm currently out of the paint bucket types so I can't check. Note to self: buy a few more since the last one cracked last month from wear and sun.

Currently, the micros are happy in one gallon nursery pots.

Just a small thought I am doing something new this year I was doing research on growing in my area came across a video of someone who lives in the same town and he made these buckets called the alaska grow buckets I bought the supplies yesterday and only got three 5 gallon buckets to
Try it out . If you come across it maybe give it a try I’ll post pictures once I get it set up in June since my husband leaves tomorrow and won’t be babk until mid June he will put them together since me and drills don’t mix haga

@AKgardener , that Alaska grow bucket thing rang a bell so I asked my sister Pickles about that. She said a long time ago she gave me information on those that she found online. Hmmm, I have no idea where that might be but I'm sure I can do a search. Ah ha! I just did a search and found the plans. I do remember seeing this.

http://www.alaskagrowbuckets.com/

Let us know how they do!

Funny you should mention the name pickles. I grew up
With this kid everyone called him pickles cause he ate so many haha. That being said the bucket idea it’s worth a shot right Whst could possibly go wrong with that

Speaking of pickles, FIrehouse Subs sells their used pickles buckets with a lid for $2 or $3. Proceeds go to their charity.

Dwarfs get quite bushy with many arms. I went to 15 gal pots to even out the temperature of the soil and for less watering. Still needed lots of watering during the hottest days. I don't think pot size matters if watering is easy for you through irrigation.

The smaller the container the more maintenance required. So your choice, how much time do you want to put into them? More time, smaller pots, less costly. Bigger pots, more costly, less maintenance. If you have an automatic watering system with fertilizer, you would probably do fine with smaller containers, at least until late in the season. If you are watering by hand I would go bigger, especially if you want to keep up production later in the season. I haven't grown them in quite a while, but I think I would go with 10 gallons personally. If they were going to be your only plants I would go with 15 gallons to get the most production and longest season out of them. I water pots manually but always have full sized garden tomatoes as well, so I didn't really rely on the dwarfs so much.

I water everything in the garden by hand as needed whether it's potted tomatoes or everything else that's in the ground. It's kind of meditative and gives me a chance to put an eyeball on everything up close and personal. It's an easy way to notice the start of any problems quick and start fixing them, be it funk or insects.