using milk jugs for greenhouses

Using empty milk jugs to get spring vegetable seedlings started.

It’s middle of winter and at this time of year we get a lot of high pressure that squeezes over the mountains from the desert. That makes for warm, windy, dry days and cold, clear nights.

Outside temperatures will swing 30 degrees in just a few hours, going from freezing at 7AM to the upper 60’s by noon. Temperatures in my unheated greenhouse will swing an even broader range faster, going from the mid 20’s just after dawn to the high 80’s/low 90’s by late morning.

That’s fine for the succulents and cacti, but, even with tray warmers and humidity domes, it’s too much for vegetable seed starting.

As a result, I’ll let the greenhouse sit empty a few more weeks and get some early crops started using the old milk jug greenhouse method instead.

As you can see, they’re nothing but 1 gallon plastic milk jugs cut in half and filled with potting soil. Add some seeds, stick the top back on, tape the seam to keep the pieces together and viola!, a mini-greenhouse.

Better yet, these guys don’t even need much sun. It’s really about keeping the soil temperatures up so the seeds will germinate and establish strong roots. If you’ve got them indoors, a little indirect light is more than enough. If they’re outside (like mine), place them next to a wall or building.

Mine are on the west side of the storage shed where they only get a couple hours of sun in the late afternoon, but the shed continues to radiate heat, keeping the little greenhouses warmer than the air temperature well into the evening.

By the end of March, all these guys will be ready to move into the garden.