We use bales for beans and summer squash.
Our biggest, sunniest garden area has nice soil, but tomato plants won’t grow there because our neighbor has a huge black walnut tree, and black walnut trees give off a toxin called juglone in the soil. So one year Dad and I tried growing some tomatoes in straw bales above the soil so the plants wouldn’t absorb the toxin. Unfortunately, our experiment failed because those tomato roots went through the bales into the soil.
Gardening in a straw bale is like gardening in a big block of compost! Here’s how to set up an above-ground garden.
Plan Your Garden
Figure out how many bales you need for your garden and where you want to put them. One bale is big enough for two tomato, squash, or pepper plants, or for several bean plants. You can use them to create a new raised bed or put them along the edge of a garden that’s already there. Set the bales out about two weeks before you want to plant them. It doesn’t matter if the strings that hold the bale together are on the side or the top.
Prepare the Bales
If you are using new bales, you want them to be wet throughout and starting to decompose before you plant into them. Water them well and sprinkle them with a high-nitrogen fertilizer such as a lawn fertilizer or blood meal. Do this three or four times over a two-week period, adding lots of water to the bales each time. The nitrogen feeds the microbes that help decompose the straw. (Nitrogen is the first of the three numbers that is shown on a fertilizer package; for example, blood meal is 12-0-0.)
A straw bale is like a big sponge that absorbs water and anchors your plants.
In his book Growing Vegetables in Straw Bales, Craig LeHoullier says that he uses a thermometer to help him decide when bales have started to break down enough so that he can plant in them. Bale temperature, he says, is often in the 80 degrees Fahrenheit (27 degrees Celsius) range to start with, but as you add fertilizer, it can rise to 120 degrees F (49 degrees C) after a few days. As it falls back below 80 degrees F, your bales are ready to plant.
Plant the Bales
Mix some garden soil with some soilless mix. Straight garden soil might pack down too much in the bale. To transplant a seedling into a bale, use a trowel to make a hole in the bale big enough for the roots, put in the plant, and fill in around it with soil mix.
To plant seeds directly in the bale, spread a 3-inch layer of soil mix on top of the bale and plant your seeds into it.
We use last year’s bales that have already started decomposing so we don't have to wait long to plant.
Care for the Plants
The straw doesn’t have a lot of food for your plants, so you need to feed your bale-garden regularly with a balanced fertilizer. Bales can dry out quickly in hot, dry weather. Check often to see if you need to water. If you’re not sure, stick your finger right into the bale to see if it feels moist inside.
You might get surprise guests! We had some interesting mushrooms appear once. They were not edible, but they were nice to look at.
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Excerpted from Gardening with Emma: Grow and Have Fun: A Kid-to-Kid Guide by © Emma Biggs and Steven Biggs, photography by © Donna Griffith, used with permission from Storey Publishing.