Everyone has a different answer based on their experience. And the variety. Mine is I trellis mine, prune out suckers, and give them 18" minimum by variety. Some get 2'. There is no matrix or program or template or plugin or anime or avatar or standard.

Dan

I go one per square. I usually only do one or two plants at different corners, so I imagine it could get crowded if you place them close together.

I've done 2sqft/plant with great results, and will do the same this year.

EG

Last year I gave mine 18" in a row 16' long along the north side of the bed. They grew well and produces lots of fruit, but I had disease problems later in the year. This year I'm going to plant them in 2 rows on either side of the box and give them a little over 3' of space between plants in the row and 4' between the rows. Both last year and this year I'm growing them up nylon vegetable netting. The only pruning I did last year that I plan on doing this year is cut off all leaves close to the ground and anywhere the leaves are bunched together and shading one another out.

I give mine 2 squares- planting 4 plants along the trellis end of a box. (so half of a 4X4 box) I would love to cut back to 3 plants, but there are too many I love- so I will just make sauce in the fall.

I agree with EG.

I also plant my tomatoes all two feet apart. I grow Roma and Best Boy tomatoes and the two feet has always done well.

Unlike others, I do not do any kind of pruning.

Here is a link that might be useful: BsnTech Gardening Blog

I was fine with this whole thread until that last note. If I understand you, you're going to plant a 4x12 bed with one 12 foot trellis down the middle and 12 tomatoes going onto it, 6 north and 6 south of the trellis.

I'd reconsider this ...

In addition to square foot per plant you need to consider linear feet of trellis per plant. My opinion is you've got too much square footage and not enough linear trellis (trellis length). If you want 12 toms on a 12 foot trellis you will need to prune severely, probably to a single stem, and if you're pruning to a single stem 4 square feet is way too much real estate.

As I understand it, part of the square foot theory is crowding plants to maximize output. Part of this is balancing the amount of ground it's in and the amount of sun it can get. If you give it way more ground than sun, you're simply wasting space. The plant is still sun limited so it's only going to grow so much and produce so much. In this case, I'd say the sun space (trellis length) and ground space (square footage) should be about equal.

My personal preference pretty much match Dan's ... 18 inches of trellis and 1.5 square feet per tomato, and I only prune suckers and low branches that obstruct air flow near the ground (which really helps with disease). I have a trellis down the middle of the north foot of the box and plant 5 plants per 8 foot long bed (or 8 per 12 foot bed for you). Better Boys grow big, and most of the heirlooms are smaller, but they'll all hit 7 foot on my trellis by late summer (except last summer - see next post)

Just my opinion,
David

David,
When you say that you only prune suckers and low branches that obstruct air flow, are you saying that you weave most branches through the trellis?

I did one per sqft last season and pruned to one main stem. It seemed like I had a lot of free trellis space. I was thinking of leaving 2-3 of the lowest suckers (above the first cluster) for this year and leave my spacing at 1 ft or even 16 inches (6 plants over 8 ft of trellis).

But if you prune sparingly at 18 in spacing, that may be a consideration as well.

2008: 8 plants/16 sqft. 2009: 6 plants/16 sqft. 2010: planning 4 plants/16 sqft. Suspect my production will be the same but easier to take care of/harvest.

snowman,

Yes, I weave. Every couple of days just before I water. I find it's easiest to weave when the plants are a bit parched. I wind up weaving the plants together a bit, just letting them flow as they like, but always encouraging them to get higher. I use 6 inch squares concrete mesh for my trellis, and paint it with rust-o-lium to keep the rust off. I love this mesh as I can reach right though to harvest tomatoes and it's very easy to train the tomatoes up it.

With hybrids like Better Boy that makes quite a dense mat, so If it gets too thick I might trim a branch mid-bush that just doesn't want to cooperate. With the heirlooms I don't seem to ever get so dense that I'm looking to lose anything.

At the bottom, my goals are to a) keep anything from touching the ground for bug and disease reasons and b) provide some air flow, again for disease. I trim as needed to do this.

I feel like with trellised Tomatoes at 18 inches I probably wind up with more plant than I can use, so trimming a bit doesn't really hurt the plant or production a bit.

Hope this helps.
David