If you’re an urban gardener who’s despaired of finding enough space to grow even a tomato plant or two, “building” a garden with straw bales creates a whole new range of possibilities. Do you have rocky, uneven, or unyielding clay soil? Are you unable or unwilling to dig up a big plot of ground to prepare the soil for a garden? No problem!
Is it difficult for you to stoop or bend to garden? With straw bales, you’ll be creating the biodegradable equivalent of a raised bed. Now imagine growing your plants in a mud-free, weed-free medium that turns to mulch after a growing season or two. Are you ready to begin?
Even if you want to start with only a couple of bales, or if this technique brings out the engineer in you, you can grow almost any vegetable, herb or annual flower in a straw bale. You can tuck a few bales along the side of your house or garden wall. A parking strip is often the sunniest spot for many urban gardeners but poor soil and passing animals can make this less than desirable for food gardening. Bales are a great solution. If you are concerned about how attractive they’ll look, tuck in a few marigolds around the base and sow nasturtiums on the corners of the bales. Plant several varieties of colorful lettuce and perhaps a squash or pumpkin vine spilling a few fruits over the side.
You can plant a wonderful kitchen herb garden right next to your house, even on your concrete patio. Imagine a neat little row with a couple of bales overflowing with parsley, cilantro, five or six different types of basil, arugula, sweet marjoram…oops, guess I’ll need to make that at least three bales.
You can use bales of grass hay as well as straw, however you should be prepared to do some more initial "weeding" on these bales as some grass seeds may sprout. You can simply pull up the small sprouts as soon as they show, or give your bales a haircut. Check to see what's available in your area, you may find that someone has a few bales of grass hay to sell that's less expensive than straw.
Plan your layout carefully. I’ve never tried to weigh a soaking wet bale of straw, but that’s because I couldn’t even budge it to begin with. You’ll not want to change your mind and move things around. Gardeners seem to be divided on the best way to lay the bales down…string side on the ground, or string parallel to the ground, so follow your fancy on this one. If you are laying out your bales in side by side rows, leave enough space to mow. Think about what you’ll be planting in each bale. Remember that whatever you plant will want all of the sun you can find.
You can grow just about any vegetable or annual you choose with the straw bale method, however the taller the vegetables the more attention you'll have to pay to staking or other support. You can plan on two to three tomato plants, four pepper or cucumber plants, or four to six lettuce plants per bale. Remember that tomatoes will have to be staked or on a trellis (always use the longest stakes you can find, the tomatoes will rise to the challenge and grow to the top). If you live in a favorable climate, you could even grow an early crop of sugar snap peas on the supports before you start the tomatoes.
PREPARE THE BALES
You’ll have to prepare the bales to make sure they’re past the initial heat of decomposing. With the proper fertilizers and water your straw bale should warm up to a temperature of about 100 degrees. As in many gardening techniques, there are proponents of several different methods. You can prepare your bales by just keeping them wet for three to four weeks prior to planting. If you prefer a more proactive approach, here’s one widely recommended method.
Days 1-3: Water the bales thoroughly and keep them damp.
Days 4-6: Sprinkle each bale with a 1/2 cup of a high nitrogen fertilizer like ammonium nitrate (34-0-0) or ammonium sulfate per day, and water it well into the bales. If you’d like you can substitute blood meal for the nitrate.
Days 7-9: Cut back to 1/4 cup of fertilizer per bale per day, and continue to water it in well.
Day 10: No more fertilizer, but continue to keep the bales damp.
Day 11: Stick your hand into the bale. If it has cooled down to less than your body heat, you may safely begin planting as soon as all danger of frost has passed.
Organic gardeners often follow a similar method to condition the bales, substituting a natural fertilizer such as fish oil or compost tea.
You can grow plants from seeds or transplants. To sow directly, top dress each bale with a couple of inches of seed starting mix and water in well. To transplant, use your hands or a trowel to make a crack in the bale for each plant. Add a little commercial potting mix around each plant. Do not use soil from your yard! It could spread diseases, bacteria and weeds to the bales. Place the plant down to its first leaf, and gently close the crack back together. Fertilize and water as necessary as your plants begin to grow. Don’t let the bales dry out, you may need to water more than once a day in the beginning. As the bales begin to decompose, they will hold more water and you should be able to water less frequently. A soaker hose placed over the tops of the bales is a great way to gently deliver water to your plants.
There are a number of great online sites for further information, cultivating tips, and conversations about straw bale gardening. Gardeners love to share their tips, triumphs, and tragedies. You’re sure to find some great stories as you do your armchair gardening planning this winter.
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