Growing toms in Seattle - pot size before transplant?

[JDelage]

All - I'm going to try to grow tomato plants from seeds this year, and then transplant them into troth-type raised beds when it's warm enough. I'm in Seattle, so that may be pretty late in the season. I have what I need to start the seeds (heating pad, etc) and for the early stage of the growth (3" pots, LED lights, etc). My question is: what size of pot do I need for the later stage, before I transplant the plants outside?

Thank you

[rainbowgardener]

Since you haven't even planted your seeds yet, your 3" pots might be enough. They can probably stay in those until they are at least six weeks old, maybe even 8 wks depending on how big they have gotten. (Counting from the beginning, not from when they went in the 3" pots.) After that, they can go in a 4 or 4.5" pot. If you can find them, look for the ones that are extra deep, like 5". You want lots of room for the roots.

Every time you transplant your tomato plants, put them deeper than they were before (bury some of the stem). Tomatoes unlike most other plants will produce roots all along the buried stem, so you give it a bigger root system that way.

[bri80]

I'm in Portland, and I transplant my tomato seedlings into progressively larger pots until I get them in gallon pots. Once they outgrow those, they go in the ground.

[rainbowgardener]

Wow, that's a lot of potting soil. Why keep them in pots so long? And are the pots indoors under lights? How do you have room for all that? Mine start in the tiny cells while they are still on the heat mats. Then they get potted up to 3" pots. Then they probably get potted up to 4.5", 5" deep pots or Solo cups. Then they go in the ground.

[bri80]

Typically temps aren't warm enough here for unprotected tomatoes outdoors until mid May. I typically start mine indoors in late Feb. So I've got to give them enough growing room for 2.5 months.

Typically they are under lights until about two weeks after repotting to gallon pots. Then I move them outside but protect them with those "Wall-o-Water" cloches until they can Be put out unprotected.

It does get crowded inside but I usually only grow maybe 5-6 tomatoes for myself. I start another dozen for friends but they get less priority (sorry friends! but they're still better than anything you can buy). I have a grow light that is 4 T5's paneled together. Provides enough light for a large area until it's time to put them outside under cloches.

[rainbowgardener]

Alternative if you didn't want to do all that would just be to wait longer to plant your seeds. When I lived with an average last frost date of mid-April, I planted tomato seed mid to late Feb. You are starting your seed about the same time, to have plants in the ground a month later....

[bri80]

Alternative if you didn't want to do all that would just be to wait longer to plant your seeds. When I lived with an average last frost date of mid-April, I planted tomato seed mid to late Feb. You are starting your seed about the same time, to have plants in the ground a month later....

Yeah, but then I wouldn't have ripe tomatoes a full 4-6 weeks before anyone else around here.