There are many fans of straw bale gardening, especially for those who lack space, want to squeeze in more plantings, or lack quality soil. See our guide to gardening in straw bales, including a straw bale conditioning chart as well as information on fertilizing and best plants for straw bales.
If you want to build a raised bed, straw bales are a great alternative, too. First, let’s talk about what is straw? It’s NOT hay!
What is Straw?
Straw is the dry hollow stalks left from cereal stalks like wheat and barley. It has so many uses. It makes a great mulch. (See our article about mulching with straw.) It can be used to grow potatoes and mushrooms, keep ponds clear, and makes instant planters, as we’ll show you.
Straw bales will eventually decompose like any organic material, but they’ll decompose much slower because the outsides are less insulated than the center. What you’re left is a shell filled with the beginning of a compost pile—the perfect planter!
Benefits of Straw Bale Gardening
The straw bale gardening method was pioneered by Joel Karsten. Straw bales used as planters have several advantages:
As straw rots, it releases nutrients, feeding the plants growing in it.
The bales raise the planting area so less bending and back pain.
It saves buying loads of compost!
They reduce the incidence of pests, diseases, and weeds. The bales are quite tall so you rarely have slugs or any insect issues.
You won’t have to water extra. Straw bales dry out slower in hot sunny weather due to their sheer size so it helps in high heat. The inside of the straw bale remains damper.
A raised bale planter also means it’s easier to harvest!
Where to Find Straw Bales
You can source straw bales from nearby farms, garden centers, DIY stores, etc. Or, try looking online. Organic bales are harder to find. You’d need to find bales from organic farms or ensure they’re marked organic. Avoid any that have been treated with herbicides.
Once home, put your bales on hard ground, grass or paving or store in a greenhouse. Ensure the twine runs along the sides. The cut ends should face up for easier watering.
What Kind of Fertilizer to Use
To get started, you will need 1. water and a 2. quick-release high nitrogen fertilizer. For fertilizer, you could use:
Ammonium sulfate
A soluble lawn fertilizer
Blood meal as an organic alternative
Straw Bale Gardening Conditioning Chart
Bales need a little conditioning before planting. You’re starting off the composting process. It’s not complicated but there is a two-week upfront process. If you’re using organic fertilizers, you’ll need to wait an extra week as the composting takes longer.
Day 1: Sprinkle 1 cup of fertilizer evenly on top of bales. Water in with 1 gallon of water. Let it soak. Day 2: Soak bales with another gallon of water. No fertilizer. Day 3 and 5: Repeat 1 cup fertilizer and 1 gallon water. Day 4 and 6: Water only. Day 7, 8, 9: Just half a cup of fertilizer, water as usual. Day 10: One cup of traditional “balanced fertilizer” (equal parts N-P-K such as 10-10-10). During this time, temperature inside the bales will increase (up to 100 degrees F), then cool back down. Day 11 and 12: Check that bales are moist.
Which Plants to Grow In Straw Bales
You can grow most anything, from leafy greens to beans to onions.
But straw bale planters are most often used for warm-season crops like tomatoes, cucumbers, peppers, and zucchini.
It’s probably best to avoid root crops as they can be challenging and corn which gets top-heavy.
How to Plant in Straw Bales
Large seeds like runner beans can just be pushed into the moist straw.
For smaller seeds, top the straw bale with an inch of potting mix and sow into that.
For warm-season crops, start them off in pots. Then plant by pulling out enough straw to fit in the root balls. Firm them in place. Make sure there’s enough contact between roots and straw, then thoroughly water.
Tips for Straw Bale Gardening
Don’t cram in plants. Plant at correct spacing for airflow and light.
Including supports for climbing vegetables such as cucumbers.
Keep crops moist with regular watering.
Feed with a regular plant or tomato fertilizer.
Keep picking to keep the harvest coming!
At the end of the season, you can use the straw in compost or as mulch next season.
See the video to truly understand how to plant in straw bales.
Catherine Boeckmann loves nature, stargazing, and gardening so it’s not surprising that she and The Old Farmer’s Almanac found each other. She leads digital content for the Almanac website, and is also a certified master gardener in the state of Indiana. Read More from Catherine Boeckmann
As we mentioned above, root crops like potatoes present challenges, but with that being said it is definitely possible.
Given the specific conditions you outlined, it’s hard to know what the outcome will be. If you do not have another option for growing potatoes, you could try growing them in the straw bales and see what happens. Even presented with the most ideal conditions, sometimes crops fail.
If high temperatures persist for a long time, you should try to find a way to provide some shade during the hottest times of the day. Consistent watering will be key to success because if there is no rain and such high temperatures, you will want to take extra care to make sure that your potatoes are given the necessary amount of water.
I have successfully used straw bale gardening in upstate NY for the past 7-8 years. We are in danger of frost right up until Memorial day & as early as late August. I am able to start lettuces, chard, other cool weather crops as early as mid to late April as soon as the bails are processed. They really do heat up well. Tomato plants, summer & winter squashes are prolific, although they generally require staking & securing to my fence posts as bales do decompose before the season is over.My husband built a frame for my pole beans& I have invested in a large trellis for winter squash to keep them off the ground. The composted bales at the end of the season are black gold for the next year. Any # of bales can be used on any surface. Highly recommend. Joel's book is highly informative. Only thing I cannot do successfully is fall planted garlic, they freeze over the winter
I have garlic planted in buckets so I can bring inside and put them in the utility room for the winter. When it's warm enough, I put them out on the deck.