Ray's Garden Rows: Straw bale gardening an (un)easy alternative

Ray Mueller

As the 2016 growing and food harvesting season have given way to an early dose of winter and as Thanksgiving ignites many thoughts of food, some people might be considering new ways of growing food or changing how they've been doing it.

There are many ways of growing food plants, starting with the traditional way of placing them in the soil. Another way that's suitable for certain species (lettuce, spinach, basil, oregano, chives, tomatoes, peppers and strawberries) is growing them in managed hydroponic and aquatic systems, which require a significant investment in equipment and supplies. In urban areas, growing food producing plants is being done on the roofs of large buildings.

Other less expensive and less labor intensive choices are the soil-based growing of plants in containers or in raised beds. I've done that in a small way for potatoes, spinach and lettuce with a damaged garbage barrel, a bathtub and a washing machine drain tank.

Straw bale option

Another idea that combines a couple of those basic techniques is straw bale gardening, which has been popularized in recent years. A good source of the nitty gritty information, available in a 36 minute instructional video on YouTube, is Joel Karsten's “The Science of Straw Bale Gardening.”

Notice the emphasis on “straw” bales. That's because those bales, made with wheat, oats or barley straw, are less likely to have the weed seeds, which can easily be a problem with hay or grass bales.

The attractions with straw bale gardening include not having to kneel or bend when planting or harvesting, being able to set the bales on solid surfaces or on grass, and avoiding mud, certain pests and some plant diseases. Straw bale gardening would also be a good choice if poor quality soil is a challenge.

A line of tomato plants are rooted in straw bale in this photo taken during the third week of June.

The nitty gritty

For the time being, I'm not going to consider straw bale gardening. I find the nitty gritty details to be a bit daunting and time consuming.

To do it successfully, the advice given by Karsten and others who have studied or engaged in the practice suggests starting a precise 10-day protocol at about 10 days before one's estimate of the last spring frost in the area.

I won't get into all of the day by day timing here but it involves watering and applying a nitrogen fertilizer (ammonium sulfate or urea) to the bales in order to get them to heat. If all goes well, that'll happen by day 11.

Once the bales' temperature drops below 100 degrees, the next step is to use a scissors or other cutting instrument to make pockets three to four inches deep in the bale as places to put seeds or young plants. Those pockets are to be filled with a growing medium such as compost, dry manure, potting soil or nutrient rich soil. When the plants are growing, there are additional recommendations for regularly supplying a 10-10-10 fertilizer (nitrogen, phosphorus, potassium) and water as needed.

Getting it done

I have a friend in the local area who has practiced straw bale gardening for several years and who gives it a thumbs up. He has grown potatoes, radish, kale, carrots, tomatoes, sunflowers other flower species, zucchini, and pumpkins in one or more years.

One caution this friend shares is to provide some kind of structure on which the vined plants can climb so their fruits won't be on the ground, grass, or pavement. Because of their prolific growth this year, he had to put support holders under the pumpkins.

In another year, he was surprised by the number of zucchini that he had but in general he finds that straw bale gardening does not increase productivity. He finds that it is better to grow potatoes in the second (and last) year that the straw bales are used.

Eggplant on the left and radish on the right in the same bale show the possibilities for growing food plants in straw bales.

Finding the bales

Finding straw bales has become a challenge because not many farmers still make the appropriate size bales, which are about 40 inches long and 15 to 18 inches wide and deep. They weigh about 40 pounds and cost only a few dollars each.

I know of only a few sources, some of which involve bales that have already been in storage for a few years. Anyone wanting to get straw bales might want to watch for any farms on which straw is baled with the older style balers. Amish and Mennonite farms might be a good source.

One caution with the bales to be sure that they don't contain weed seeds. Another problem identified online is getting straw from grains that were killed with a herbicide because of a herbicide carryover that would affect the food plants. This practice is apparently common on the West Coast and the Rocky Mountain states but I'm not aware that farmers terminate their small grain crops that way in Wisconsin.