Our Straw Bale Gardening Experiment

by Marty Fisher, EMGV

After three painful years of crop-destroying diseases on our beloved heirloom tomatoes, my husband and I decided to give straw bale gardening a try.

I had tried grafting—attaching an heirloom scion onto a hardy root stock—for two years with some success, but it was a long, painstaking process, and we still weren’t getting the yields we enjoyed in the days before the dreaded fungal, viral, and bacterial diseases took over in our garden. We also tried disease-resistant tomatoes like Early Girl, Better Boy, Celebrity, Sweet 100, etc., but we missed the complexity of flavors and variety of colors of our favorite heirlooms like Carbon, Amana Orange, Green Zebra, Pineapple, Lucky Tiger, and more. We also tried removing the lower branches of our plants to keep them away from disease spores in the soil as well as spraying with copper sulfate—it all seemed a lot of work for a limited return on investment!

I started researching straw bale gardening in January, thinking it offered the advantage of a sterile environment for the tomato plants as well as the effect of a raised be d. I found a book written by the man who pioneered the concept, Joel Karsten. He came up with the idea after observing healthy, vigorous weeds sprouting in old straw bales on his family farm. He began experimenting with vegetables, and over decades, developed the techniques for gardening with straw bales. Since then, he has published two editions of his book, Straw Bale Gardens, and has spoken all over the world about what is touted on the book jacket as “the hottest new method of veggie growing.” The book contains a wealth of useful information, plans, diagrams, and more.

Our first task was to find straw bales—they must be wheat straw bales, not hay. They are not cheap, especially given the size of our garden. The best price we found was about $6 a bale. We inquired about delivery and were told by several farm supply stores that they sell the bales at a loss or break-even and were not interested in delivering them. So, several pick-up truck trips later, we had lots of bales on our garden site.

The next step was placing and conditioning the bales, a process that takes 10-12 days. Conditioning should be started two weeks before the average last frost date.

Although I had reservations about the fertilizer recipe given in the book, we decided to just follow the instructions and evaluate the results. Over the conditioning period, fertilizer and water are applied to the bales according to a day-by-day schedule. My reservation concerned the recommendation of nitrogen-rich “traditional refined lawn fertilizer.” Instructions are also given for organic nitrogen sources, but this seemed more complex, and we followed the conventional method. Fertilizer is sprinkled over the top of each bale, and water carries it deep into the bale, starting the bacterial process of breaking down the bales to release nitrogen.

On Day 10, the instructions call for one cup per bale of 10-10-10 general garden fertilizer, watered in.

Planting can begin on Day 12. A little sterile potting soil can be used to anchor the plant in the straw bale, but all the nutrients and growing medium the plants will need are contained within the conditioned bales. Adding garden soil or compost could introduce fungal spores to the sterile bales.

Results

Our concerns about using lawn fertilizer were confirmed over the spring and early summer: TOO MUCH NITROGEN! Our plants quickly became enormous, with fewer blooms than normal. They also began to shade out the eggplants and herbs that we had planted beside the tomato plants. We added a phosphorous- and potassium-rich fertilizer and gradually the plants started to have more blossoms and bear fruit. We also noticed that plants growing in straw bales require more diligent watering. Karsten recommends placing soaker hoses on top of the bales, controlled by a timer.

In researching this article, I found an N.C. Cooperative Extension Service article (see “Hay” Bale Gardening link below) that recommends a different conditioning method. It calls for simply watering the bales for three days. On Day 4, you add 2 cups of dolomitic limestone and a half cup of ammonium sulfate, and water it in. On Days 5-9, you add more ammonium sulfate, followed by a cup of 10-10-10 or 8-8-8 on Day 10. Planting commences on Day 11.

This year we did lose a few plants to “the *%#* fungus,” our common term for fungal, viral, and bacterial diseases including early blight, late blight, fusarium wilt, tomato spotted wilt, various cankers—you name it. My husband also sprayed the plants with copper sulfate as a preventative.

Overall, we deemed the straw bale gardening experiment a success. We canned, made salsa, roasted, sliced, and froze plenty of colorful tomatoes to get us through the winter. We plan to try it again next year using the Extension Service-recommended fertilizer recipe.

I also plan to graft tomatoes again next year after taking this year off. And, I’ll give some of the newer disease-resistant varieties a try. Some I’m particularly interested in include Iron Lady, described as “super resistant,” and Mountain Magic, which was developed by Dr. Randy Gardiner, professor emeritus at North Carolina State University. Apparently, some breeders are also developing disease-resistant heirlooms, including two old favorites of mine, Lemon Drop and Mr. Stripey.