Direct-seeding next year

Originally Posted by brownrexx

It depends on how long your growing season is I guess. My seedlings that I set out in May are probably 6 weeks old and I get tomatoes and peppers in late July.

If I direct seeded my plants I guess that I wouldn't get fruits until late August or September and that is too late for me.

My soil is too cold for seedlings of warm weather plants like tomatoes or peppers to do much growing before the middle of May even under milk jugs.

How cold does it get when you would want to do it?

Hmm. You might be surprised what milk jugs can do if you haven't tried them, yet. The plants won't grow or sprout well, if at all, while the cap is on (I'd only recommend leaving it on if a storm is going to damage your plants or something; in my area, I just throw the cap away; you don't need the cap at all to protect the plants from any of the freezes I've tried them in). They need outside air to grow (and the lack of air may even kill them; some people probably confuse the damage they endure from lack of air with overheating, since they talk about how the sun can kill them easily even when it's cold, which is not my experience without a cap). I've had newly transplanted Yellow Pear tomatoes grow just fine when it was either 19 or 23° for the night-time low, in a warm February, under a milk jug (they were at the side of our house in shade, though, which may have had more protection than an area with direct sun). Those were transplants and not seeds, though, but seeds should be able to germinate under a milk jug and grow a considerable amount before the last frost. They do in my unheated, small greenhouse, in March and April, anyway (and it's basically like a giant milk jug). They take longer to sprout in March than April, though, but I think it's worth the head-start if the work involved isn't a big issue (although germination rates may be better in April).

The main challenge with starting seeds under milk jugs is perhaps watering them (and/or the soil issue I mentioned in another comment), especially if you put dirt around the jugs to lock them in place. I've found that I can water the interior of milk jugs with the mister option on my hose nozzle. So, as long as it's not too cold to be good for a hose, that could work.

You'll want to make sure any early milk jug plants and/or plants in a small, unheated greenhouse, have plenty of phosphorus, though. Plants seem to need more of it when it's cold (especially small plants; my Yellow Pear transplants weren't particularly small, and they were kind of old, seeded indoors extra-extra-early; those didn't need extra phosphorus—it must have been sufficient in the soil). Monopotassium phosphate seems helpful for my greenhouse.

Phosphorus is also important because it helps plants mature, which could be very important for areas with shorter seasons.

I'm personally not planning to do most of my direct-seeded plants under milk jugs (just unprotected, like weeds and hope they survive the elements like the reseeded tomatoes and weeds do). However, if I wanted to start them extra-early (as in before April 10th or so). I would use milk jugs, and I do want to do at least some plants like that. I might do more if I have an abundance of jugs (but I'm not counting on having them). Our average last frost date is about May 10th. This year it seems to have been later (or at least the risk of frost was there much later, whether or not it actually frosted).

I recommend removing the jugs as soon as it's warm enough for tomatoes.

I pulled up those Yellow Pear plants early because they had pithium on their stems while indoors, and although they didn't seem bothered by it outdoors, I didn't know much about pithium's level of contagiousness outdoors at that time; so, I pulled them up even though they looked healthy. They probably would have been fine. I think pithium is naturally in the outdoor soil anyway.