Any kind of raised bed makes for an easy, convenient garden, but one technique that is especially effective is straw bale gardening. Sometimes known as bale gardening, or hay bale gardening, a straw bale garden uses ordinary farmer's straw as the principal growing medium. Conditioned with a small amount of potting soil, compost, and fertilizer, the straw itself breaks down gradually, providing its own nutrients over the course of the growing season.
What Is a Straw Bale Garden?
A straw bale can make a great growing medium, and a straw bale garden is a raised bed in which the potting soil, compost, and plants are all housed inside the straw bale.
Straw bale gardening is a great way to grow herbs and vegetables, and can also be used to grow ornamental plants. It's economical, easier on your back, and is great for people with mobility issues.
Consider the pros and cons to determine if straw bale gardening is right for you.
Tips for Straw Bale Gardening
For effective straw bale gardening:
- Use straw, not hay. Hay is made from alfalfa and grasses that still have the seeds attached, and these seeds will turn into weeds when they germinate and sprout. Straw, on the other hand, is comprised of the leftover stalks of grains such as oats and wheat—after the seeds have been removed through harvesting. Hence, straw is virtually weed-free, which makes for an easy-care garden.
- Locate the garden near a water source. If you can, put your straw bale garden near a water source. Any garden takes a fair amount of water, and it's helpful to be right near a hose.
- Solarize the bales. If you solarize the bales by wrapping them in black plastic for several weeks before you plant them, the heat will kill any remaining seeds that might otherwise sprout. It also speeds along the process of breaking down the straw into nutrients the plants can use. Remove the plastic before you begin planting.
- Use short plants. Corn, sunflowers, tomatoes, and other upright plants may grow too tall to be supported by the straw bales. And stakes are difficult to use in straw bales unless you can drive them down through the bales and into the earth. You can either grow smaller varieties of tall plants like tomatoes or keep them pruned to train on wider, shorter trellises.
- Plant in full sun. Nearly all herbs and vegetables prefer full sun locations—defined as six to eight hours per day or more. If you have only part shade locations, make sure to use plants suitable for that exposure—such as lettuces and other leafy vegetables.
- Avoid pooling water. Don't position the straw bales in low-lying locations where water pools. Too much standing water can cause the bales to rot, and it can even drown plants.
Equipment / Tools
- Garden trowel
- Straw bales
- High-nitrogen lawn fertilizer
- Potting soil
- Plant seedlings
- Wire fencing (optional)
- Balance water-soluble fertilizer
Configure the Straw Bale Garden
Once soaked with water, straw bales are very heavy, so plan the position of your straw bale garden first, before planting. The most important criteria is to have a location with plenty of direct sunlight—at least six to eight hours daily for most vegetables.
The bales should be postioned on-edge so that the sheared ends of the plant stalks are facing upward and the bands of twine are along the sides.
Arrange the bales in whatever configuration is convenient for your style of gardening. Some people like to arrange the bales in a straight row, others arrange them in an L or U configuration. The bales can also be abutted against each other to form a larger raised bed, but make sure you can still reach to the center of the garden for tending the plants.
Be aware that as the bales decompose they shrink so the spaces between the bales will get larger. Some gardeners fill these spaces with additional compost/soil mixture as they appear.
Prep the Bales
Prepping straw bales (sometimes called conditioning) involves starting the decomposition process before planting. Proper prepping requires a week to 12 days.
After the bales are arranged in your chosen configuration, spread a generous layer of high-nitrogen fertilizer on top of the bales. Water in the fertilizer, making sure to saturate every bale, every day for several days. Add more fertilizer every couple of days, spreading it generously, then soak the bales each time. A high nitrogen fertilizer, such as that used for lawns, is the best formulation to use for this conditioning stage.
After you notice the straw beginning to get warm and decompose, spread a mixture of potting soil and ordinary compost over the top of the bales in a 2- to 3-inch layer. When placed over straw that has begun to decompose, this is the only growing medium you need.
Plant the Garden
To plant seedlings in a straw bale, simply take a sharp trowel and stick it down into the straw, wiggling it back and forth to make room for the seedling. As usual, make sure to plant seedlings no deeper than they sit in their nursery pot. Also, try to place taller plants toward the back of the bale, so that when they grow, they won’t shade the smaller plants.
If you are staking taller plants, make sure to use long stakes that can be driven all the way through the straw bale and into the ground.
Seeds can be planted directly into the soil/compost layer, then watered in. Make sure to keep the soil constantly moist until the seeds have sprouted and are well established.
Tend the Garden
Like most raised gardens, straw bale gardens resist many common garden pests. But there are several critters that will not hesitate to scale your bales and eat your entire harvest. A fence may be mandatory to prevent pest such as groundhogs or rabbits from decimating the harvest. An inexpensive wire fence may discourage these pests. Serious vegetable gardeners may want to invest in a large fencing structure constructed of chicken wire and stakes to surround the entire garden.
Water regularly to keep your straw bales moist. Like any raised garden, straw bale gardens consume a lot of water. In the heat of the summer, this may mean watering every day. It’s best for plants to water in the morning, making sure to water the bale, not the leaves. Excess water will drain out the bottom of your bales so your plants don't sit in water. Plants are much less susceptible to drowning in a straw bale garden.
Even though plants will get nutrition from the internal decomposition of the bales, you still need to fertilize them, though it's required less frequently than with in-ground plants. A monthly application of a balanced water-soluble fertilizer is sufficient. At the end of the season, you can let the bales decompose, using the remnants the following season as mulch. Harvesting root vegetables such as potatoes, carrots, and onions often means breaking apart the entire bale—which is largely decomposed by this time—to extract the vegetable roots.