Hay bales provide a gardening medium that offers many benefits to the home vegetable garden. The hay bales create a raised bed, which offers better drainage, easier accessibility and fewer weed problems than a traditional bed. The hay bales also compost down throughout the gardening season, adding needed nutrients to the vegetables growing in them. Straw bales usually have the fewest weed seeds and are readily available, but wheat, barley and rice hay bales can also be used.
Determine the best location for the bales. Choose an area that receives at least eight hours of sunlight a day. Position and set them up so the twine runs parallel to the soil.
Soak the bales with water, providing about 15 gallons per 40-pound bale. The bales should be as damp as a sponge when properly watered.
Sprinkle 1 pound of limestone and 1/3 pound of ammonium nitrate on each bale. Work these fertilizers into the bale with a garden fork.
Water the bale as needed to maintain this level of moisture for the next 10 days as they compost. The bales should heat up within three days; if not work in 2/3 pound of ammonium nitrate to jump start the composting process. Bales heat up to 100 degrees F or more as they compost.
Mix 1 part soil with 1 part compost once the bales cool down to the touch, usually within two weeks of fertilizing. Place 3 to 5 inches of compost mixture on top of the bales.
Plant the vegetable seedlings in the compost mixture on top the bale. Dig a hole in the compost and set the seedlings in the hole at the same depth they were at in their nursery pots. Firm the compost around the seedlings with your hands after planting.
Water the bales throughout the gardening season so that they stay moist but not soggy. Provide enough water at each irrigation so that the water penetrates the interior of the bales where the vegetables roots are.