For full size indeterminate plants, the bigger the better - 10 gallons is my preference. Determinate varieties will do ok in 7 gallons. 5 gallons is the minimum recommended.

Dave

if you do not want a smaller plant how do you plan to move a five ft. or larger plant in to your house and grow under
lights ?,my preference for a indet. is at least 15 gallon
min., the bigger the pot the bigger the plant and more fruit good luck.

les

Growing a full-size tomato plant indoors under lights is tough. It's hard to give the plants enough fresh air, humidity, and cool nights, and the absence of predators causes insect problems to proliferate. Grow lights give off a lot of heat and the light intensity falls off quickly as you move away from the light. To grow a tomato plant properly, you'd need to spread out its foliage to form a canopy at roughly equal distance from the light, which would then take up a lot of space; probably a 1,000-watt HID light per plant. You might be better off extending your growing season outdoors at both ends with hoop houses.

I do just fine with plants like Cherokee Purple and Box Car Willie in pots ranging from 5-10 gallons. Five is little small, so they require a little bit more attention in the form of water and fertilizer.

I would actually be less concerned about the size of the plant and more concerned about the amount of light, and nygardener gave you some good information about it.

Oops. Size of the pot, not size of the plant.

I started out with 5 gal for cherry tomatoes and 10 for everything else. I have moved cherries to 10 gal and 15 gal for the rest. The plants are much happier, I spend less time watering and fertilizing - and the tomatoes are much bigger.

Pots are expensive so its OK to move up a bit at a time. When you do, you will see the difference. (I noticed the same with my peppers - amazing difference.)

I don't know if you start your plants from seed or when you plant out but I do just fine here in Vermont. I start seeds the end of March and plant out the end of May. I've got lots of toms and the heirlooms are likely to be done before it turns too cold. The cherry toms will linger until close to frost.

nygardener's advice is a great option if you want to extend your growing season.

Our last freeze was June 15, and it was down into the 20's (F) at night all of May. My tomatoes didn't go into the ground until late June.

I start them indoors, under lights, early in the spring. 2 weeks before they go out, they are moved outside under shade cloth to harden them. But they often have to be carried back inside at night. It depends upon what the weatherman says.

By the time they go out into the ground, they are crowding their 2 gallon pots.

I always hope it doesn't freeze again until the end of October, but the tomatoes are usually covered at night all through October.

I have a raised cinder block bed that can hold 8 large tomato plants. That's got a hoop house, and I use heat at night to give the tomatoes more growing time, and lights to try to fool them into thinking it is still summer. I still get a lot of green tomatoes pulled and brought inside to (hopefully) ripen.

I just started 2 tomato plants that will live their entire lives in pots. I'm going to bring those inside, into my plant room and see if I can get them to bear over the winter. Lights on timers to mimic summer daylight length. House is heated to an even temperature, but if the tomatoes want more heat, I can add heat to just the plant room or put the pots on the heat mat.

My grow lights are 4 ft shop lights with "cool daylight" bulbs. They work very well and don't give off much heat.

Plant room is used for starting seeds and was designed to over-winter the potted citrus. But we've discovered a nice place to keep the citrus out in the living room, so the space for the citrus pots has come available for a couple of pots of tomatoes.

Large plants are hard to move, so I'd like to get them into large enough pots and leave them be. It's indoors, and gigantic pots take up a lot of space. So, I want big enough pots, but not any bigger than necessary.

OregonWS;
I have done OK with some 6 gallon pots, and also have "transportability" concerns... pot size, weight, plant height.

Come late September the best are going into a 10x10 tent greenhouse. Some MIGHT come out for a nice week of weather, dont know, but they have to be safely moved.

I think a 6 or 7 gallon pot full of a mix that is light weight when dry might be what I am looking for.

I have some 10 and 12 gallon guys with some nice looking green tomatos, might have to go to Harbor Freight and see what they have for 'wheeled conveyances' for cheap. Wife's "Little Red Wagon" may get re-purposed a little.

You might need a little make shift ramp to clear any door thresholds and other obstacles.

Anyway, you are not the only one thinking like this- us short season guys still want Fresh tomatoes till Thanksgiving.

Mmm - I guess my zone 4 garden is in a pretty good location. I use a small unheated greenhouse in the spring. The sun heats that up nicely and the toms grow like crazy with just a week or so in there - were almost 3 feet tall when I put them in their final containers this spring. We don't generally get a frost until late October here in the Champlain Valley so I don't bother with it in the fall.

If you have a really short season, you might consider planting in containers at the beginning of the season. They warm up faster, the toms get a great start and they can be moved if needed.

As well, toms in containers often come in sooner than those in the ground because of the more protected conditions. You can control the water, fertilizer and it is, as previously noted, a lot easier to rescue them from frost than when they are in the ground.

Container gardening is just a bit different and it gives one better control over the short season - why not give it a try?

I've been harvesting cherry toms since mid-july and my others for several weeks. I have 19 toms in containers and they are all producing very well.