We decided to try Straw Bale Gardening because we wanted to increase production and get an early start on the growing season. This type of gardening is different from what we’re used to, but we’re excited to see how it goes!
We left and treated our bales on a spectacular weekend just weeks from the first day of Spring.
Setting and Conditioning the Straw Bales
After the bales are situated, the next step of SBG is to “condition” the bales to start the composting process. Any organic fertilizer will do, but we’ve had great success with Milorganite.
A non-burning formulation of Milorganite that includes a bit of iron to boost the plant’s ability to make chlorophyll is more than just fertilizer. It also has a strong deer repellent.
12 Steps to Set up a Straw Bale Garden
- Select rectangular bales that are firm and tied tightly.
- Place the bales in a sunny location. Most plants need at least six hours of sunlight each day. Plants such as tomatoes that do not receive this much sun will not produce as much fruit. Once the garden is in place, you will not be able to move the bales.
- The surface where you put your garden should be a place that can accept a runoff. If you are gardening on concrete or on a rooftop, you will need to provide a place for the runoff water to go. You can place the bales on a tarp. This will divert the water to other areas so that it is not concentrated directly in one spot.
- Place the bales so that the bindings are facing upward and the grain of the straw or hay is parallel to the ground. Do not cut the bindings.
- Completely soak the bales with water from a garden hose once or twice daily for three days. If you are gardening on a rooftop, be aware that a 50-pound bale will hold 125 pounds of water. Make sure the surface you are gardening on will hold this weight.
- On the fourth day, add two cups of dolomite lime and 1/2 cup ammonium sulfate to the bale. Mix this fertilizer into the top of the bale by scratching it into the grain of the hay or straw fibers with a gardening fork and water it in by once again saturating the bale.
- Add fertilizer to the bale for the next five days. If you are gardening organically, use manure tea as your fertilizer. If not, use 1/2 cup ammonium sulfate. The ammonium sulfate or manure tea will activate microbes that decompose the bale in the center of the hay.
- On day 10, add 1/2 cup of a balanced 8-8-8 fertilizer or one cup of a 10-10-10 fertilizer. The numbers on the package represent the total amount of nitrogen, phosphorous, and potassium in the fertilizer.
- Add another 1/2 cup of this fertilizer once per month as your plants grow. Never fertilize the bales more than once per month after they have been planted.
- The bales should be ready to plant on day 11.
- Create a top cap of soil for the bale garden by mixing bagged potting soil and bagged, composted manure from your local garden center. Spread this over the top of the bales in a four-inch layer. Manure must be composted to eliminate weed seeds.
- Plant vegetable transplants by pushing aside the top cap and pulling the straw fibers open. Place the root ball of the plant directly into the straw fibers. Then push the fibers closed around the root ball and move the top cap back in place.
A bale of hay is large enough to accommodate two tomato plants or four pepper plants, but you may plant any type of vegetable in your straw bale garden. The ideal time to plant a spring garden is just after the last yearly frost date in your region. As for a fall garden, it should be planted by midsummer.
Make sure to check on your bales of hay daily once you have planted them. This is to see if they need watering or not. Even if the outside of the bale appears to be moist, the inside needs to stay damp like a rag that has been wrung out.
Straw-Bale Gardening Q&A With Craig Lehoullier
I invited Craig LeHoullier–the author of “Epic Tomatoes” and the breeder of dwarf tomatoes–to my public-radio show and podcast. He talked about the straw bale gardening how-tos from his home and garden in North Carolina.
The following is a transcript of the February 20, 2017 edition of my public-radio show and podcast.
A: When Michelle first asked me about the process, she actually spoke of hay bales. I think this is a common mistake – people often refer to straw and hay interchangeably. However, they are not equivalent in this case.
B: The word “straw” usually makes me think of something that is hard and often has a hole running through the middle. Wheat straw is probably the type of straw that most people think of when they hear the word. It is strong and does not break down easily. This is important because it means that farmers can use it for a longer time. Hay is made of thinner grass and it does not last as long as wheat straw. Anything that is organic will eventually fall apart, but wheat straw lasts longer than other materials.
Where I live, hay is usually made of timothy or other slender, soft grasses. Our straw here in the Northeast is usually made of oats.
Having used hay or straw as mulch before, I have noticed that more weed seeds sprout in the hay. Is this another negative aspect of using hay bales?
Not a negative aspect; because the bale is elevated, a lot of the grasses that would germinate are easily removed.
I’m glad you mentioned oat straw, because it’s functionally similar to wheat straw in that it makes really good straw bales. Whereas something like pine straw is much harder and takes much longer to break down, so it’s not as useful. Wheat straw bales will sprout, and you get beautiful wheat grass growing in them. You can leave it or you can pull it out as you wish. So it’s not really so much of a bother, just an attribute.
To me this is just dirt, just what’s in my backyard, but it had dangerous levels of herbicide A: Joe Lamp’l told me about “killer compost” a couple years ago. Apparently, if you spray persistent herbicide on straw or hay, and then animals eat it and excrete it, the herbicide will still be present in their feces. This astonished me, as I had always thought of dirt/soil as being safe.
You may have problems if you use straw or hay that has herbicides in it as mulch. You should be careful about where you get your straw bales from and ask any necessary questions.
The speaker is talking about organic growers using straw bales as a growing technique. The speaker suggests that organic growers should ask about the source of the straw bales, to make sure that there are no persistent herbicides sprayed on them. The speaker says that if the plants thrive in the first year, it’s a good indication that the straw bales are from a good source.
You can’t trust anyone, especially if you’re buying your bales from a big-box store. They may not have control over the source for a given batch of bales. So be careful.
A: In addition to straw bales, you will need some tools and materials for your straw-bale garden. These include a sharp knife or gardening shears, a spade or trowel, some fertilizer, and some plants or seeds.
The key to successful straw-bale gardening is timing your purchase of the straw bale correctly. Straw bales have very few nutrients and are mostly made up of structure. The idea behind straw-bale gardening is to add nutrients to the top of the bale, which will then start to create compost. This is where the roots of your plants will go to find nutrients and water.
I recommend waiting two to three weeks before planting crops in a straw bale. The cooler weather will slow down the internal composting process.
For a general idea of how many bales you’ll need, think in terms of two eggplants, two tomatoes, and two pepper plants. This will give you a good idea of the spacing required between plants.
A: Yes, in one bale you could get two tomato or eggplant plants.
A straw bale costs about the same as two 20-gallon containers of potting mix, which is a great deal.
To start the composting process, you need a source of nitrogen. If you’re not concerned about using only organic materials, you can use a lawn starter that contains 29-0-4. Ammonium nitrate, calcium nitrate, ammonium sulfate, and urea are other possible sources of nitrogen. If you want to use only organic materials, you can use blood meal, Milorganite, fish emulsion, or bat guano.
And just to be careful, if you’re going to use a lawn product that’s not organic, make sure to read the label to see if it’s a weed-and-feed or if it contains any herbicides.
B: You could charge your bale up to make it inhospitable to your plants.
A good fertilizer to use after plants start to break down would be a balanced food like 10-10-10 or the blue stuff. Regular gardeners would know this. Another option would be a granular organic like worm castings or alfalfa meal.
A: You need to make a pocket in it for your fertilizer and pour it in there.
Applying the Nitrogen Day 1: Apply the granular or liquid to the top and water it in deeply. Day 2: Just water. Day 3: Repeat Day 1. Day 4: Repeat Day 2. Day 5: Apply the Nitrogen and water it in deeply. After about seven days of this cycle, you will have applied the Nitrogen five times.
If you stick a thermometer in a nitrogen-soaked, balanced fertilizer and the ambient temperature is 40 or 45 degrees Fahrenheit, the internal temperature could reach 120 or 130 degrees Fahrenheit. This is essentially a compost bin that’s starting to happen.
You shouldn’t plant until the temperature drops to 75 or 80 degrees so that the roots don’t get damaged by the heat.
B: It is better to wait two or three weeks before planting in order to let the bales decompose a little bit. Planting sooner will not give the bales enough time to decompose which will cause problems.
A: There is no set answer to this question, as everyone experiences things differently. However, generally speaking, you may be able to smell something or see something when it is time to plant. Additionally, the thermometer may give you an indication that things are ready.
You can reach your hand in the bale of straw, and it will be a little soft and pliable inside. People are always amazed when they see me planting my tomato plants in containers using this method. I’ll take a trowel and make a little space for the plant in the bale. Then I’ll seat the plant in the space and add some potting mix around the base of the plant to make it level. I don’t hollow out a section and fill it with planting mix; I just seat the plant with its rootball and whatever planting material is attached to the bale, as if I am planting in a container or in the ground.
After you water it, it’s done–planting in a bale is quick and easy.