Planting tomatoes in a bale of hay may seem like a strange gardening technique, but it's actually a very effective and practical way to grow a healthy crop of tomatoes. For gardeners without a plot of tillable land, hay-bale gardening is a way to garden in a relatively small space. It is also an ideal solution for wheelchair gardeners or gardeners with sore backs or stiff knees because it requires little bending over. One bale can easily support two large tomato plants. The hay bale will require preparation, so start at least ten days ahead of time.
Purchase a bale of hay or straw at a farm supply center. Straw bales from wheat or barley work well for bale gardening. The straw is what remains after the wheat or barley is harvested, and so there aren't many weed and grass seeds. Hay bales will have more seeds because they contain the complete plant, but are usually less expensive than straw bales. If possible, purchase a bale that has already begun to decompose.
Decide where you want the bale garden before you begin, as the bale will be very heavy and difficult to move once it's soaked with water. If you want to protect the surface under the bale, put the bale on a large piece of plastic sheeting or a plastic tarp.
Position the bale on the ground with the twine ties parallel with the ground. Don't cut the twine.
Soak the bale with water until it is drenched clear through. Soak the bale again on the second and third day.
Sprinkle each bale with about 2/3 cup of ammonium nitrate on the fourth day. Water the ammonium nitrate into the bale.
Water the bale again on the fifth and sixth days. On day seven, apply another 2/3 cup of ammonium nitrate, and water it in well. Soak the bale with water on days eight and nine.
Sprinkle a cup of balanced general-purpose fertilizer over the top of the bale on the tenth day, and water the fertilizer in thoroughly.
Spread 3 to 5 inches of commercial potting soil or topsoil over the top of the bale on day eleven. If desired, the potting soil or topsoil can be mixed with half compost or peat moss. This top treatment will help the bale to retain moisture, but it isn't absolutely necessary. If you prefer, this step can be skipped and you can plant the tomatoes directly into the bale.
Pull the hay apart with your hands, and plant the tomato plants in the split area. If the hay is tight and difficult to pull apart, use a trowel or other prying instrument. Plant the tomato plants in the split area. One bale can support two tomato plants.
Water the bales as needed, and don't allow the tomato plants to dry out. When the tomatoes are about the size of a quarter, feed the plants with a fertilizer formulated especially for tomatoes, and apply according to the package directions.