They would probably work fine, but they might be hard to cut in half and drill drain holes in. I used to use the plastic bottles cranberry juice comes in, but stopped because the hard plastic isn't as flexible or easy to deal with as milk jugs and 2-L soda bottles.

If they have a really wide mouth you might want to cover with plastic wrap with holes punched in it, too.

Caryl

Thanks Caryl. I an also going to use 16 oz plastic cups. I can't seem to find how much soil I should put in them though. I just measured one and it's about 4.5" high. I've read that winter sowing should be done in 3-4" of soil. If I do that, that leaves somewhere between 1.5" and .5" for the seedling to grow before it hits the cling wrap. Is this a problem?

Hi PMSmith, do the peanut butter jars have a hard plastic top that is opaque? Generally, you want a clear cover over your containers that is easy to poke holes in. The holes allow a little precipitation to seep in, allows the container to respirate (it can get very warm in the container in the sunlight!). Also, the clear tops allow sunlight to penetrate which produces the mini-greenhouse effect, and give the seeds the light that some require to germinate.

3-4" of soil is fine, and sometimes even a little less. Some people like more head room for the seedlings, but I've found that once the seedlings need head room I've removed the covers because it's warmed up enough in the Spring.

With wsing seedlings, they are often growing below the surface and developing an impressive root system (especially perennials), sometimes more so than foliage growth.