Milk Jug Greenhouses: Easy Way to Start a Garden

Usually I order most of my garden seeds for the year in January or February. A few weeks later I put together milk jug greenhouses. These easy, miniature greenhouses help give seedlings a jump start on the growing season. You can make them any time before your final frost date. Frost dates do vary by region.

Usually I put my milk jug greenhouses together sometime between January and March. In Northern Ohio, where I live, the final frost date is typically mid-May. This post will explain how to make the miniature greenhouses, what supplies you need and tips for starting your garden early. Really these can be made any time before that final frost date. Some years I do not get around to transplanting my seeds until a few weeks after the frost date.

Milk Jug Greenhouses

How to Make Milk Jug Greenhouses

The first time I made milk jug greenhouses I followed Kevin’s winter-sowing process. He also lives in Zone 5, but in New York state. It helps to know your hardiness zone when figuring out when to plant seeds and when to make these greenhouses.

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Milk jug greenhouses can be made from milk jugs or water jugs (if you buy water by the gallon). You only need a few other supplies an the entire project can be completed from start to finish in less than two hours.

Here’s a brief summary of how I make the milk jug greenhouses:

• Save and clean milk jugs or water jugs for a few weeks prior to planting.
• You will need one jug per variety of plant you are growing.
• Cut the top off the milk jugs with a box cutter knife.
• Leave one side of the top attached, so the jug has a “lid.”
• Puncture the bottom of the jug with several small holes for drainage.
• I use a small ice pick to do this. You could also use a power drill.
• Add soil and water to the bottom of the jug.
• Be sure to use a seed starter soil and NOT soil from your yard or garden. Then plant your seeds.
• Seal each jug with duct tape.
• Label the jugs with a Sharpie marker and leave the cap lids off the jugs.
• Place the jugs outside in an area where they will not blow away or be knocked over.

A Few More Tips

After I made make milk jug greenhouses the first time I realized I needed to cut the top of the greenhouse higher – near the handle – because mine were tipping over pretty badly. If you cut higher on the jug you can also add a little more soil.

Also, I recommend mixing your soil with some water in a 5-gallon bucket and then scooping the soil into the containers. The first year I did this project in our basement and it was rather messy. Now I typically put the jugs together in the garage and then carry them outside once I’m done.

Any mess can simply be washed down the drain in our garage. Alternatively, you could also make these directly outside. Paint sticks work wonderful for mixing the soil. I tried “watering” the soil after I put it in the containers and it turned into a mess. Add the soil to the bucket first, then add a little bit of water at a time and stir. It should be a thick mush.

I like to store the jugs close together between two raised beds. The first year I made these they were more in the open and the sun and rain beat down on the labels and I had a few mystery jugs as a result!

You can write on the jug itself with the Sharpie marker or on the duct tape – or if you are paranoid like me – you do both and label each jug at least twice. I also noticed that by storing the jugs close together the labeling tends to not wear off as easily. They are sort of “protected” that way.

Why Do I Have so Many Milk Jug Greenhouses?

The first year I made these, I had 40 of these greenhouses because I was planting a lot of perennials. I was trying to establish a new landscape after removing four-dozen evergreens from our yard. I do not normally have that many milk jug greenhouses. Typically I have about 12 to 15 milk jug greenhouses each year to jumpstart my vegetable garden.

After reading several organic gardening books that year, I fell in love with the idea of edible landscaping. Grown plants are more expensive, and I do have time on my side so I mostly plant by seed, although I have ordered a few young fruit trees and rose bushes by mail. Most of the seeds I use in the milk jugs are vegetable seeds. I do start some annual flowers and herbs in the jugs, too.

Here are some of the seeds I purchased through Botanical Interests (my favorite source for organic and heirloom seeds!) to use in my milk jug greenhouses this past year:

In Summary

Homemade milk jug greenhouses are a quick and easy way to start your garden early. There is no need to wait until after your frost date to plant your seeds. Keep in mind you can make these greenhouses anywhere from four to 12 weeks before your final frost date.

Have you tried making milk jug greenhouses?

*This post was originally published in 2013 and has been updated and republished for accuracy and comprehensiveness.