Gardening with straw bales is becoming very popular for lots of very good reasons. This method is easy, produces great results and it eliminates many drawbacks of gardening that keep some people from growing their own vegetables.
For starters, straw bale gardens are easy to set up and materials are readily available from local farmers and farm supply stores. For people who have stopped gardening due to arthritis or problems getting around, straw bales are a God-send. There’s no need to bend or kneel or till or hoe or spend hours in the sun pulling weeds. The bales can even be stacked two high so that people who use a walker or cane can walk right up to them. Bales work well for people who have small yards – just a couple of bales on a patio will grow a bumper crop of tomatoes or peppers.
Be sure to buy straw bales. Hay bales are not suitable for this project because hay contains seeds. One of the best things about straw bale gardening is that it almost totally eliminates the need to weed. New straw bales are sterile (meaning they don’t carry fungus or disease) and free of seeds - and the lush plant growth keeps everything shaded – so no weeds! Crawling insects don’t bother to burrow into or scale the bales to get to your crop.
There’s also no need to dig or till the soil. You can put bales right over areas of lawn, on top of septic drain fields, over heavy clay or in places in your garden that are depleted of nutrients. There’s no need for traditional crop rotation because there are no soil-borne issues. Elevated crops allow for improved air flow and strong plant stems.
If you have soil that’s contaminated by fungus or pesticides, put down a layer of heavy landscape cloth under the bales. Landscape cloth also works well between rows of bales – or you can simply trim or mow right up to the edges. It’s not a good idea to put straw bales on wooden deck surfaces, because the moisture will affect the deck boards. Be sure to place the bales a good distance away from fences or building.
Sunlight is key to your success. Choose a sunny, well-drained area of your yard or patio that gets at least 6 – 8 hours of light a day. Orient the bales north to south to catch the most sun. Place the bales with the cut straws facing up to allow water and air to penetrate down inside. Leave the string in place on the sides to hold things together. Be sure that your bales are close to a hose attachment or rain barrel.
Add tomato cages, if you wish. Or you can drive 7’ metal stakes (T fence posts) at the ends of the line of bales and string wire (12 - 14 gauge fencing wire works best) at several levels to support climbing or heavy vegetables. The first row of wire is strung about 10” above the bale with two or three more levels at 10” intervals. This gives good support to stems laden with tomatoes, squash, beans and cucumbers.
Extend the growing season
To create a mini-greenhouse over your bales, you can stretch 2- to 3-mil plastic sheeting over the support wires early in the growing season. The sheeting will protect tender plants on cold nights (45° or lower). The plastic can be raised as the plants grow taller and removed when daytime temps reach 65°.
To make watering easier, run soaker hoses along the tops of the bales and attach to your water source – be sure that the holes in these hoses face down into the bale. You can add a timer for watering when you’re not around. Water early in the morning to allow things to dry out during the day.
Bales act like big square planters filled with decomposing straw. The break-down of the straw generates warmth that lets plants grow very early in the season when night temperatures are still chilly. The idea is to increase the nitrogen level to get the bales “cooking.” This is the same process used to make compost, but bales are not turned to aerate them.
Straw bales and compost piles are equally alive with microbes and worms– while the heat kills off harmful bacteria. Because the straw bale method relies on the decomposition work of beneficial bacteria, there’s a 12-17 day preparation schedule – or “conditioning” cycle to follow before planting.
Prepare the bales
The Traditional Method uses commonly-available turf fertilizer (but only the kind without herbicides). The Organic Method gives the same results, but relies on fertilization from organic sources such as bone meal, feather meal or blood meal. Well-composted chicken manure can be used on a 50:50 radio with another fertilizer source.
In USDA Zone 7 a-b, so you can start working on the bales about two weeks before the last frost of winter. At the end of the 12-17 days of conditioning, the bales are broken down inside enough to make nutrients available to plant roots.
ON DAY ONE: Set the bales in their final pattern. Add ½-cup of fertilizer evenly across each bale. Water the fertilizer in well from the top. Avoid using cold hose water, since this may slow down bacterial activity. Note: The Organic Method substitutes 3 cups of an organic nitrogen source on days 1, 3 and 5.
DAY TWO: Water bales until thoroughly saturated, using warmed water from buckets or rain barrel.
DAY THREE: Spread another ½-cup of fertilizer evenly over each bale and wash it in with warmed water.
DAY FOUR: Soak bales thoroughly (1 – 2 gallons per bale) until water runs out the bottoms.
DAY FIVE: Add ½-cup fertilizer to each bale; wash it in with w
wash it in with warmed water.
DAY SIX: By now, you should notice a slight elevation in bale temperature and a pleasant, earthy scent that signal the progress of conditioning. Water again thoroughly with warmed water to encourage bacterial growth. If the temperatures have been cold, conditioning may be delayed - just continue the process as planned.
DAYS SEVEN THRU NINE: Add 1/4-cup fertilizer to each bale, followed by warmed water. Note: The Organic Method uses 1 ½ cups of organic source fertilizer on these days. Bacteria are working hard at this point and the bales may get 10° to 40° hotter than outside air temperatures. Any flies buzzing around the organic fertilizer will dissipate as the fertilizer gets incorporated into the bales.
DAY TEN: Spread one cup of general garden fertilizer (10-10-10) on each bale, to add more phosphorus and potassium. Be sure this fertilizer doesn’t contain any weed killer. You could also use 50% wood ash for potassium and bone meal or fish meal for phosphorus. Mushrooms may sprout at this point– just leave them be as they will not harm anything. Water the
bales and check for any cracks along the sides where water may escape. Just spray more water into these cracks and don’t be tempted to pack them with soil from your garden.
DAY ELEVEN: Be patient and let everything “cook.”
DAYS TWELVE THRU SEVENTEEN: Using the Traditional Method, you’re ready to plant. Your bales are warm, moist, weed-free and disease-free: the perfect place to introduce tender plant starts or to spread seeds. Things won’t look much different from the outside. Stretch the soaker hoses across the tops of the bales before planting and secure with U-hooks of wire. Note: If using the Organic Method wait to plant until at least Day 17.
Plant seedlings - or start from seed
To plant seedlings, use a hand trowel or serrated knife to cut down into the top of each bale. Rock the trowel back and forth to open a hole large enough to insert the whole root mass. A pair of pliers can also be used to remove straw to make more room. If the inside of the bale feels hot to your hand, it is probably too hot (over 105°) to plant transplants. Check the temperature with a meat thermometer and wait a couple of days for things to cool down. Be gentle with plant roots – don’t let them dry out and don’t force them down into the bales. Cover any exposed roots with a handful of sterile potting mix and water gently.
Seeds can also be planted on bales. Create a seedbed by spreading sterile potting mix 1 – 2 inches deep along the tops of bales and out to the edges. Use a board to pat the mix down. Follow the seed packet regarding the spacing and depth at which the rows of seeds are planted. Seedlings will germinate fast due to the warmth of the bales. Be sure to thin the seedlings to the recommended density.
Everything planted on straw bales matures early, so crops can be replanted often during the season. If bales get a little heavy in late summer and start to tip over, stake a long board against the sides for support.
Another advantage of straw bale gardening is that at the end of the gardening season, the straw is totally recycled. Bales can be broken apart to spread out under other plants as mulch. Or they can be piled together and allowed to compost, to add their nutrients back into the soil next year.
Straw bales truly are a break-through concept for creating beautiful, functional, productive gardens for everyone.
Southside Master Gardener Association, Halifax County, VA