Conditioning is Essential to Straw Bale Gardening

Gardening is one of the top leisure activities enjoyed by Tennesseans of all ages, and straw bale gardening is gaining favor with seasoned and novice gardeners alike.

Alan Windham, a professor of plant pathology with the University of Tennessee Extension, compares straw bale gardening to gardening in containers—minus the container. Flowers, vegetables and herbs can be grown in straw bales. Given that Windham studies plant diseases, straw bales seemed a perfect fit to avoid soil-borne pathogens like root knot nematodes. Windham spoke on straw bale gardening at a recent lawn and garden show in Dickson, Tenn.

“There are definite advantages to planting a garden in straw bales,” Windham said. “First, you have an instant, rather inexpensive raised bed; second, there’s no cultivation or digging involved, and third, soil type doesn’t matter.” The primary considerations for a straw bale garden are a sunny location and a nearby water source. As the bales are essentially containers, they’ll need to be watered frequently during hot, dry weather.

Some bales are more preferable than others for gardening. “Bales of wheat straw work well as there are few weed seeds in the bale. Bales of hay are more likely to have numerous weed seed and may have pesticide residues that could be harmful to vegetables and flowers,” Windham said.

Before you plant into bales, they need to be conditioned. Windham says conditioning involves wetting the bale over a period of 12-14 days and adding a small of amount of fertilizer to soften the bales and get them ready for planting. “A few days after initiating conditioning, add a one-half cup of urea or ammonium sulfate to the top of the bales. At the end of the conditioning period if the internal temperature of the bale is 99°F or less, it’s time to plant. During the season, you can fertilize plants with fertilizers designed for container plants. Follow the label instructions to determine the amount of fertilizer to use,” said Windham.

Finally, insects and plant diseases may show up on the foliage and fruit of developing plants. Windham recommends that you manage these as you would in a traditional garden. “As your bales weather and decay through the season, mushrooms and slime molds may appear from the wet straw. These are not plant pathogens and are not a problem,” he said.

For more information on gardening, you may call or visit your local county Extension Office. To view Windham’s presentation on straw bale gardening, go to the UT Soil, Plant and Pest Center website: ag.tennessee.edu/spp/ and click on the “presentations” link under the “publications pull-down menu. Follow the UT Soil, Plant and Pest Center on Facebook for timely discussions of gardening issues in Tennessee.

Photo: A. Windham