Straw bale gardening is touted as providing all the benefits of raised beds without the cost. Poor (or absent) soil can be overcome by growing vegetables in bales of straw. Also, if your soil is host to Verticillium or Fusarium wilt, nematodes, or really tough weeds, straw bale gardening may be the answer. Or, it may not.
Like other Quick Fixes, straw bale gardening is more complex than simply sticking some seeds into a bale of straw and adding water. First, straw bales do not contain enough of the nutrients needed by garden plants. Also, your straw bales will begin to decompose as plants are watered. As the bales decompose, they also generate a significant amount of heat (up to 140°F). These temperatures can kill your plants. Preconditioning is necessary to create temperature, chemical, and microorganism stability.
Preconditioning straw bales for gardening
Preconditioning takes approximately 2 to 3 weeks to complete. The preconditioning process is a controlled composting that makes nutrients available to whatever you will be planting in your straw bale garden. In a standard compost pile, the ratio of carbon to nitrogen is 30:1. A bale of straw is closer to 40:1 or even 100:1, so nitrogen must be added.
These preconditioning steps are needed for successful straw bale gardening:
When are my straw bales ready for planting?
If synthetic fertilizer is used, you can start planting on Day Twelve. If organic fertilizers were used, wait until Day Seventeen. Before you start planting, however, you need to consider other potential problems.
Potential problems with straw bales
Aside from decomposition and the need for frequent watering and fertilizing, straw bales are often produced in fields where persistent herbicides are used. These herbicide do not breakdown quickly and they can adversely affect your crops, your compost pile, and your soil. If you do not know for sure, you have to assume that these chemicals are present and are best avoided. If you can find organic straw bales, you are ready to move forward.
Seeds vs. transplants
Crops that are grown from really tiny seeds, such as lettuce, are best started in potting soil and then transplanted to the straw bale garden. Otherwise, those tiny seeds will end up somewhere in the middle of your straw bale where the only thing they can do is decompose. Adding a shallow layer of potting soil on top of your straw bales can also eliminate this problem. Use a trowel to open up a space in the straw bale for transplants and be sure to water after adding plants or seeds.
What can be grown in a straw bale garden?
Each bale of straw can be used to grow a surprising variety of plants. You can grow 2 or 3 tomato, squash, or melon plants, 4 or 5 pepper plants, or as many as 15 bean plants in a single bale. You can also grow potatoes. The most critical issues of a straw bale garden are water and nitrogen. If either of these are in short supply, your plants will suffer.
Feeding and watering a straw bale garden
Drip emitters and soaker hoses are your best bet for a straw bale garden. Early in the growing process, more water will be needed as plants send roots throughout the bale. Since straw bales are not soil, it is important to monitor your plants for signs of nitrogen deficiency. Stunting and chlorosis (yellowing) are the two most common signs. Normally, monthly feedings will be sufficient.
Until your straw bales completely decompose, you can have multiple plantings, especially if you keep tightening the twine. As the bales decompose, they will shrink. You can keep them compressed by tightening the twine with a stick inserted behind the twine and rotated over the twine as many times as it takes to keep it tight, tucking the stick behind the twine.
Straw bales gardens may last for more than one season, but they will ultimately decompose. Once the bales are unusable as growing mediums, they can be added to the compost pile or used as mulch.
What have you grown in a straw bale? We’d love to see photos!
You can grow a surprising amount of food in your own yard. Ask me how!
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