Straw bale gardening: a cheap and easy way to grow

If you’ve got terrible soil, a limited budget, or need a temporary garden, straw bale gardening might be the thing for you. 

Straw bales are convenient packages of organic matter—straw. When used to grow plants, you are essentially container gardening, but with a straw bale instead of a pot. However, it can be much more affordable and, once set up, very low maintenance. 

Most annual vegetables (and, of course, flowers) that we grow in the ground can also be grown using the straw bale gardening method. Gardeners have had tremendous success with this method of growing tomatoes, cucumbers, leafy greens, cabbages, peppers, and more. Even root crops like potatoes, carrots, and sweet potatoes can do well in straw bale gardens. 

Some garden needs are the same, whether growing traditionally in the ground or in a straw bale. You’ll still need a sunny spot and access to the garden hose for watering. But other problems can be decreased when using straw bales. Hard, rocky, or compacted ground is no issue, and even poorly draining soil and heavy clay are not a problem with this method. There is no digging involved, and weed pressure is much less. You’ll also find there is less need to bend over!

Most folks find they can use a straw bale for two years at best before they lose their ability to support a crop. But that’s no reason to frown. All that now degraded straw is well on its way to being composted and makes a great soil amendment for other areas where you may grow plants. 

Unique Advantages of Straw Bale Gardening

Straw bale gardening is perfect for growing plants in areas you might not want to dig up, and the bales can be set right on the grass if desired. It’s especially useful as a way to get a garden started right now without equipment or a big investment. Put in a straw bale garden this year and mulch between the rows of bales, and next year you’ll have a sod-free spot ready to amend with old, partially rotted straw soaked in fertilizer. 

While straw bale gardening is almost weed-free, grass and weeds can still grow up from the ground the bale is sitting on. For a low-maintenance and visually pleasing garden, lay down weed-blocking landscape fabric under the bales and in the aisles, set your bales, and then spread mulch over the exposed fabric. You’ll have a tidy-looking garden and won’t have to worry about grass growing up at the base of the bales. 

Straw bale gardening can reduce problems with soil-borne diseases like early blight of tomatoes or Septoria leaf spot as well. By growing above the soil, the opportunity for the spores of those pathogens to land on leaves and infect them is greatly reduced. If you’ve had issues with these diseases before, try a straw bale experiment and see if your crop does better with the new method. 

Finding Bales

For many folks, the big question is, where do I find the bales? While you may find straw bales at the home improvement store, they’re probably obnoxiously overpriced. I saw them at a leading nationwide store for $35 a piece! Don’t do that. Instead, check out local ads and look online at sites like Facebook Marketplace or Craigslist. You’ll often find bales for $5-7 apiece in late summer and fall. Store them under a tarp for spring.

**A note: look for straw, not hay. While the conditioning process we’ll describe below will kill some weed seeds, hay typically has many more weed seeds than straw and may have residual issues with herbicides. Straw typically will give fewer problems. If you are concerned about herbicide issues, try a germination test. Condition a bale from the batch and plant a few peas in it. If they pop up and grow fine without any oddly shaped leaves or other symptoms, the bale is probably clean.

Conditioning the Bales

A straw bale fresh from the field isn’t ready to grow anything. It’s dry and not all that fertile. Remember, straw is often used as a “brown” or source of carbon in a compost pile. But to make your pile go through the composting process faster, we add “greens” or good sources of nitrogen. Conditioning your straw bales will require the same thing–adding some nitrogen.

While there are many different recipes for how to condition the straw bales, the basic idea is to add water and nitrogen repeatedly over about 10-14 days. Just like a compost pile, you’ll now have browns, greens, and moisture. The bales will start to heat up as the process gets going, and then the temperature will return to ambient. That’s when it’s time to plant.

To condition the bales:

1. Grab a source of nitrogen fertilizer and your hose.
2. Sprinkle a cup or two of fertilizer on top of the bale and water it in well.
3. Come back and repeat the process, watering daily and providing fertilizer every other day. 
4. Watch the temperature. If you don’t have a compost thermometer, just stick your hand partway into the bale after a few rotations. It should feel warm. Be careful, it could be quite warm! 
5. After 8-10 days, stop applying fertilizer but continue to keep the bale moist. The temperature will start to come down, and it’s planting time.

Make sure you’ve placed the bales where you want them before you start conditioning. After several days of watering, they become much heavier and harder to move.

Fertilizing

Besides the initial fertilizer supplied when conditioning the bales, you’ll probably need to provide a generally balanced fertilizer several times over the growing season. Whether organic or not, choose a water-soluble product that contains a balance of NPK, nitrogen, phosphorus, and potassium. Just after planting and again a month later is a good starting point. 

Water Needs

Similar to container gardening, you’ll need to water straw bale gardens more than crops planted directly in the ground. If you only have one or two bales, a watering can or your garden hose will do fine. If your straw bale garden is larger, consider installing a drip line or similar irrigation system on a timer. It will make your watering automatic, and you’ll be able to leave town for a trip without finding a neighbor to tend your plants. 

Like plants in pots, a straw bale garden may require daily watering during hot and dry weather, especially if growing large plants that uptake a lot of moisture. Check the bales with your hand. They should be damp but not soggy. 

Suitable Crops

Straw bale gardens can grow nearly anything, and if you aren’t sure about a particular crop, grab a bale and give it a try–the experiment won’t cost you much in time or money. Many people find that “above ground” crops like cucumbers, tomatoes, peppers, leafy greens, and such do better for a bale’s first year, and root vegetables like potatoes and carrots do better in the more decomposed and soil-like consistency of a second-year bale.

Shorter crops work best. Tall plants like sweet corn can blow around in the wind, breaking apart the bales or just tipping over. Choose bushy, shorter-formed plants or prepare vertical trellising systems to support taller tomatoes or beans. A cattle panel or a few wires between two fence posts can support tomato vines and keep the garden looking tidy. Interplanting in straw bales is easy and creates a visually appealing garden. Grow beans with your cabbage or plant melons between your tomatoes. 

Remember to plant some flowers for the pollinators and for your vase. Easy-growing flowers like zinnias, marigolds, and bachelor’s buttons make great splashes of color between your tomatoes and zucchini plants and contrast well with the green foliage and the browns of the bales.