Joel Karsten’s book, Straw Bale Gardens, which I reviewed here, is, in my opinion, a good read. It is liberally illustrated with photographs plus drawings depicting how to best design a straw bale garden. But I had questions. Why bother? Straw bales are heavy, prickly and large. Why not stick with raised or flat-bed gardens and soil? Karsten, a horticulture graduate from the University of Minnesota, agreed to an interview, first explaining how he got hooked:
“I remember seeing bales decomposing next to our barn, even as a young kid of eight or nine, and I noticed how the biggest weeds grew in them,” says Karsten who started experimenting with growing vegetables in bales in 1993. “Necessity is often the mother of invention, and after having purchased a home with very poor soil in the backyard which was inadequate for a vegetable garden, I sought alternatives. Making major soil improvements is very expensive and as a young homeowner that wasn’t an option. So, I turned to the straw bales, and my experiments proved they work extremely well as a substrate.”
The whole idea seems simple: get a straw bale, spend some time composting the middle of it (Karsten calls this process “conditioning”) to create a growing medium, erect some support trellises for climbers like pole beans or tomatoes, then plant, water and harvest.
Here, Karsten provides his top five reasons for straw bale gardening.
1. The bales’ raised height is great because it allows full access for those who find ground-based gardening work difficult, says Karsten.
2. The fact the bales should be relatively sterile and weed-free is also key: people love the idea they can grow vegetables without pulling weeds all summer, he explains.
3. “Bales are warm early in the season when ground soil is cold, which makes planting into a bale advantageous,” he says.
4. “The inside [of a bale] becomes soil through conditioning, which means we are planting into virgin soil that never harbours disease or insect problems from previous plantings. Thus, no crop rotation is required.”
5. “Finally, at the end of the season, we can compost bales, so the following spring you have huge volumes of the beautiful compost. Work it into problem soils, and use it to fill annual flower containers, window boxes and hanging baskets. The ‘media’ it creates is spectacular in texture, drainage ability, moisture-holding capacity and fertility.”