A friend introduced me to a new way of growing herbs, in a canning jar. She said she had grown basil successfully in a jar. She took a quart jar and put pea gravel in it with potting mix on top. Then she added water to where the gravel met the potting mix and planted seeds. She placed the jar in a south window, and within two weeks had basil coming up. She claimed the evaporative power of the water up through the soil kept the soil moist enough for germination and growth of the seed.
I wondered how much gravel, how much potting mix, and won’t the roots bake in the sun through the clear glass or rot eventually in the small container with no drainage? I googled “Mason jar garden.” Much to my surprise, many articles came up. While I had never heard of gardening in a jar, it seems it’s a pretty popular idea.
The first thing one article said is that any quart-size or larger jar will work, such as a mayonnaise jar. The next thing it mentioned was, starting with seeds in the jar was not likely to be successful; use seedlings instead. However, my friend did plant seeds.
Then the article talked about drilling holes in the jar for drainage. I don’t know about you, but I’m not drilling holes in glass! It did mention the alternative of putting an inch of gravel, pottery shards, colored stones or marbles in the bottom instead of drilling. I like the idea of colored marbles adding interest on my windowsill. Another author said put two inches, rather than one, of pebbles or marbles at the bottom. Of course, more rocks at the bottom means less soil for roots. Add potting mix to within an inch of the top of the jar. Moisten the potting mix thoroughly and keep it moist, but not soggy. Place the jar where it will get six hours of sun each day. When the herb gets too big for the jar, replace it with a new plant.
I’m going to try this technique on my kitchen window, since the squirrels will eat anything I put outside. It’s also a great idea for folks who don’t have any outdoor gardening space, but would love to grow herbs. The canning or recycled jar garden also works well to grow herbs indoors through the fall and winter.
JoAnne Skelly is Associate Professor & Extension Educator, Emerita at University of Nevada Cooperative Extension. She can be reached at firstname.lastname@example.org.