ask-ruth-pictureDear Ruth,

Please give me the true dirt on straw bale gardening. I have read info online about this method of gardening and it sounds like it would cut down on a lot of work and cost. Straw Bales vs. making a new set of raised beds.

Much Thanks and Happy Gardens,

Lynne Michael

 

Dear Lynne,

I have never actually had a straw bale garden. Once I gardened on the beach by utilizing straw bales to frame the edge and floor of the garden (essentially walling in some imported soil). So…I researched the basics of straw bale gardening online and found lots of material, including Youtube videos. I also interviewed three knowledgeable local gardeners who often teach at the Organic Growers School ~ Jeff Ashton, Andrew Goodheart Brown, and Chuck Marsh.

One of the main advantages of the straw bale approach is that you can set a garden up almost anywhere and quickly ~ even on a concrete driveway, a patio, or a balcony that can support the weight of a wet straw bale. The straw bale will provide a relatively weedfree and disease-free garden area, and makes a great alternative when you have uncooperative hard-to-work soil, an awkward/steep location, or limited space. It will also be easier to work for those who are disabled or have trouble bending. Most garden plants can be successfully grown in a straw bale garden.

The Straw Bales:
Straw bales are available for purchase at most garden centers and feed-type stores. Buy wheat (or grain) straw, not pine straw or hay. These bales typically measure about 18” x 14” x 36” and weigh about 50 pounds. Choose bales that are in good condition and are mold-free. Avoid bales that are starting to fall apart, and keep in mind that straw is pretty messy (if you plan to haul the bales in your car, bring along a tarp or old blanket to contain the mess).

Siting your Garden:
Like any garden, your straw bale garden will need 6-8 hours of sun, and access to water. Proximity to your house is always helpful. Make sure you are happy with the location of the bales before wetting them. Once the bales are wet they will be very heavy and prone to breakage should you try to move them to a different location. Theoretically, the size of your straw bale garden is limited only by the number of bales you obtain. I would not make the garden any wider than 2-3 bales so that you can comfortably reach your veggies for harvest. Most straw bale gardeners recommend setting the bale on its side (the cut edge) so that the strings are not in contact with the ground. Others (only if the strings were wire or synthetic) laid the bales down horizontally. The bales that were laid down horizontally retained more water. Regardless of orientation, if you are using more than one bale, push them tightly together to achieve better water retention. I might try banding the group of bales together with string or wire.

Getting Started:
Once you have the bales in place, wet them thoroughly. Water once or twice a day, and don’t let the bales dry out for a week or two. It takes a lot of water. The bales will heat up and begin to decompose. It’s optional, but you can jump-start the decomposition process by adding fertilizer. This will get things “cooking”, however the addition of fertilizer will mean you should delay planting until the bale “cools down” enough. For instance, spread about 3 ½ cups of organic fertilizer (like Harmony 5-4-3) across the top of the bale, or create a layer of 1/3 Blood Meal (12-0-0), 2/3 Bone Meal (0-12-0), and a Potassium source, and water thoroughly. Once the bales are a little decomposed, they hold water a little better. Ideally, you would start this process in the fall and your bales would be ready to plant in spring. If you wait until spring to get started, it will take at least a couple of weeks of attention before the bales are cool enough for planting.

Planting:
Transplants can be planted directly in the bale. Andrew suggested using a digging bar or heavy rebar to force a hole in the straw bale where you want to plant. Both Chuck and Jeff also recommended excavating a hole in the straw bale and adding some garden soil, compost, and fertilizer. Laid on their cut sides, each bale will accommodate about two large plants or three medium plants. If laying the bales horizontally, you could probably grow about six smallish plants (like lettuce or cucumbers) per bale. Trailing plants like cucumbers, beans, or winter squash could be planted more thickly. If you are planting seeds, add a 2” layer of compost to the top of the straw bale before planting the seeds. Transplants are more successful than seeds using the straw bale method. Tall plants like corn and okra are not well-suited to straw bale gardening.

Ongoing:
Your straw bale garden must be watered and fertilized on a regular basis. It takes a lot of water to keep the bale moist; particularly at first ~ once the bales are a little decomposed they become better at retaining water. Jeff watered his straw bale garden heavily before leaving for a four-day weekend…his garden was tottering on the edge of a grim fate when he returned. If you added fertilizer initially, remember that was simply to start the decomposition process. Now you will need to fertilize on a regular basis to provide the plants with nutrients so they can grow and fruit. Liquid fish fertilizer (or a fish/seaweed blend) once a week is a good choice. Chuck pointed out that the raw bale has no natural fertility, so you will have to be generous with fertilizer. If your plants look off-color, be ready to add supplemental fertilizer. Wheat may sprout up from seeds in the bale. Just trim it off with scissors (rather than pulling it out). Harvest and enjoy your vegetables!

Comments from the experts:
Jeff was writing an article on straw bale gardening, so he wanted his straw bale garden to be a successful endeavor. His garden was a conversation piece in the neighborhood; neighbors and strangers would stop and chat about the oddity in the driveway. Jeff harvested cherry tomatoes and basil from his garden, but felt it was not that productive and that it used a lot of water. Even though a straw bale gave him more “real estate” on the surface than a pot, he felt that growing conditions in a pot were superior to those in his straw bales, and that the plants in his straw bale just did not thrive the way they would have in soil (either in a pot or in the ground). After the fact, he pulled the bale apart to examine the plant roots. The roots looked stunted ~ maybe because they were searching for nutrients (even though he had fertilized). Jeff also suggested putting plastic under the bale to prevent the bale from staining the driveway. Another upside…he had some really nice compost when he was done.

According to Andrew, straw bale gardening really shines in an urban setting. Sites without much potential for gardening otherwise ~ pavement, super-compacted soil, toxic soil, etc. ~ make excellent locations for straw bale gardening. He also suggested locating straw bale gardens along the edge of ponds, theoretically making watering less of an issue as the bale would be watered from the bottom.

Chuck reported good results and mixed results with straw bale gardening (growing mostly collards and kale). “It’s actually a fairly effective way to do things if you are dealing with concrete and hard surfaces…it works well on a rooftop because its relatively
light compared to soil. If planting on a roof, put a piece of plastic under the straw bale and wrap it a few inches up the sides of the bale.” Chuck obtained better results by setting a wood frame made with 1” x 4”s directly on the top of the bale. He filled the frame with good garden soil, compost, and ½ clay. If he was in the process of developing a new garden, Chuck thinks his resources (those same straw bales) would be better utilized by creating a sheet mulch (lasagna) garden, and that the sheet mulch garden would be more productive. “It’s easy to create an instant [straw bale] garden with minimal labor, but it’s not as maintenance-free as it’s cracked up to be. The main challenges are adequate fertilizer and giving it enough water at first.”

Conclusion:
A straw bale garden would be less expensive to set up than a raised bed garden (when using the soil recipe for Mel Bartholemew’s square-foot gardening method). You can set a straw bale up anywhere, and it would be less complicated to set up and get started. It would require lots of water and fertilizer and more ongoing vigilance. It would be a great way to start upgrading a garden space over time, because you will be creating lots of awesome organic matter. I think the raised bed would be more expensive and more labor intensive to set up initially, but in the long run…a raised bed garden would probably produce a more bountiful harvest.

One bag of compost costs about the same amount as one bale of straw. If I had tools to turn the soil, I would probably choose to buy compost and turn it into my soil in a 50/50 native-soil:compost ratio. The resulting garden area would be about the same size growing area as your straw bale. The soil would retain water better than straw (therefore conserving a valuable resource), and the growing medium would be vastly superior to straw because your plants could draw on the wealth of nutrients and additional resources available in the garden soil. If you want to experiment with a fun technique or are confined to a site that dictates using straw bales (concrete, hard-packed soil) try using the straw bale method. At the very least, you will have some awesome compost material at the end of the season!

So Lynne, given all this information, I suggest that you weigh the pros and cons of straw bale gardening and decide what method would work best for you in your particular situation. If you do go ahead with a straw bale garden, I would love to hear about the
results.

Happy Gardening,
Ruth

Special thanks to Jeff Ashton, Andrew Goodheart Brown, and Chuck Marsh.

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Ruth Gonzalez

Ruth Gonzalez

Ruth Gonzalez is a former market farmer, current gardener, and local food advocate. She has written numerous local food and gardening articles, blogs about local food, and writes the “Ask Ruth” Gardening Column for Organic Growers School. In her job at Reems Creek Nursery, Ruth offers advice on all sorts of gardening questions, and benefits daily from the shared wisdom of local gardeners. She has a special affection for clouds and finds delight in the natural world at every turn. Read more from Ruth at her blog: http://tailgatemarketfanclub.wordpress.com/