Using milk jugs to warm seedlings

Here in the Phoenix area, we plant and transplant our spring/summer veggies right around March 10-15, although some years late February is suitable while keeping a close eye on the weather reports. I know you use Wall-O-Waters to extend your growing season. What are your thoughts about plastic milk jugs? Do you think cut-off jugs as mini greenhouses would be adequate to raise the soil temperatures underneath them to germinate squash, cucumbers, etc, a month or so before the last frost date? I know there are many variables involved in this process, but just some opinion or insight would be appreciated. I think the jugs would probably protect seedlings from any last-minute LIGHT frost…I’m wondering about raising the soil temperature enough to germinate seeds. In mid-February the nights are still cold, sometimes with frost, but many of the days are already in the mid-70s. Would the daytime temps, with the help of the milk jugs, be adequate to start those seeds popping? I think I’ll experiment around with it this coming spring and see what happens.

Dallen Timothy
Gilbert, Arizona

While the cut-off plastic milk jugs certainly do protect seedling plants from light frosts and help warm the soil during the day, I’ve found that they really don’t do a lot to raise the soil temperature enough to counteract the cool nighttime soil temps. If you don’t want to buy Wall o’ Waters, you might try using black plastic as a mulch in your rows, planting through slits in the plastic, then setting your milk jugs over the plants. The plastic mulch really does help warm up the soil for those early plantings and makes a huge difference in the harvest, come fall.

For us, using inexpensive, homemade plastic hoop houses makes a huge difference in getting things off to a good start early. You can even make row covers over hoops of wire, above your black plastic mulch for even greater protection. And the plastic row covers tend to stay in place better than individual plastic milk jugs in a stiff wind. — Jackie

Canning ham in half-pints

I want to can ham and beans in half-pint jars for my father. Do the half-pint jars require the 90 minute processing time or can they be processed for a shorter time? I love your cook books and articles. Thank you for such wonderful guidance.

Lancaster, Missouri

They are processed for 75 minutes, as are pints. I’m glad you like my books and articles! It’s fun to connect with my BHM family. — Jackie


  1. We are located in the Copper Basin of Alaska so it takes even more frost and ground warming effort than Minnesota. We have two 12 by 24 hoop houses with three raised beds each. For plants like squash and tomatoes I use black woven ground cover which seems to suppress weeds better than plastic. Early in the season (late April or early May) I fold the edges back and plant early spinnich, lettuce, radishes and turnips. We use wire hoops and agribond row cover over the bed. For beans and such we use IRT plastic and transplant started plants through slits next to drip irrigation tube. We use IRT under low hoops in the main garden for the cole crops. The row cover keeps the root maggots down. We bought hoop benders from Johnney’s Select in Maine and are using EMT low hoops over the outdoor raised beds and cole crop rows. I think they work better than plastic pipe hoops.
    The IRT plastic warms the ground better than black plastic as it is designed to allow the infared to pass through. All of our gardens are irrigated with drip irrigation as we have to haul our irrigation water and live in an area with an average of 12 inches of rain/ snow a year.

  2. I do the same thing Anita does, works for me too. Staples come in long and short versions. I prefer the long ones as I have wind. You can also pile up dirt around the bottom of the jugs or push them in the ground a little. Having plants under jugs or WallOWaters also keeps bugs away from the young plants. I did have one very cold spring when nothing germiinated and transplants died but only a hoop house would have helped.

  3. My mother used #10 cans, the big industrial size 3 qt. plus a bit, to start tomato seeds in the garden and covered them with clear plastic. This was in southwestern Kansas. I was pretty young, but I think she probably tied the plastic on with a string. I did the same several weeks before our frost free date a couple years back and used rubber bands to hold the plastic and some big cans from buying dehydrated vegetables. The little plants were small compared to nursery plants and I bought several plants, but a month or so after the frost free date they were both about the same size, which surprised me a bit. If you were doing lots of plants, I think a row cover would probably be easier to do and maintain.

    Happy Thanksgiving to everyone. I, for one, am very thankful for Jackie and her advice.

  4. I live in western CO, I use plastic milk jugs and they work great. To keep them secure I punch a hole on opposite sides near the bottom and use a garden staple to hold them on the ground. I also use Wall o Waters but I still use the milk jugs for many plants and have for years.

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