If you are interested in growing potatoes in straw bales, then you’ve come to the right place. We’ll walk through how to prepare a site for your straw bale potatoes, how to plant your seed potatoes, how to care for your plants, how to harvest at the end of the season, and how to cleanup afterwards.
Preparation of Straw Bales for Growing Potatoes
Before you can plant any potatoes, you need to prepare your straw bales for growing. That includes choosing a suitable location, getting the straw bales you will need, watering your straw bale, and adding fertilizer to the mix.
Choose the Ideal Location for Your Straw Bale
Potatoes require full sun, meaning that they need 6 to 8 hours of exposure to sunlight each day.
You might want to keep your straw bales near your house, to allow for easy watering. This is fine, but make sure to plant on the side of the house that gets sunlight all day (in the northern hemisphere, it is the south facing side of the house). Don’t plant so close to the house that the potatoes are shaded by the house’s shadow!
Also, be sure to avoid planting near trees or shrubs that may block sunlight to the potato plant once things start to green up in spring.
Your straw bale does not need to be placed over soil. You can put your straw bale on a driveway, patio, or concrete walkway, since the straw will be providing the growing medium for the potato plant.
One final note on your straw bale growing location: choose an area close to your compost pile or bin. This will make cleanup much easier at the end of the growing season.
Buy or Gather Your Straw Bale
If you know someone who keeps horses, they may have a supply of straw that they are willing to share with you for a reasonable price.
If not, you can buy your own straw online, from Amazon, or you can buy it locally. Many stores such as Tractor Supply and Michael’s will carry straw bales. You can also try Home Depot or Lowe’s, although these stores might be more seasonal.
Remember that a bale of straw can weigh 50 to 100 pounds, or more if wet. If you can’t lift that much by yourself, then be sure to recruit a strong friend to help you to pick up the bales, and to put them in the location you chose at your house.
One final note: you can use a container (such as a raised bed) for the straw, but no container is needed. All you’ll need to cleanup at the end of the season is a rake, shovel, and wheelbarrow.
Add Some Fertilizer
Your straw bale may not be able to provide all of the nutrients that your potatoes will need to grow – at least, not right away. Luckily, there are plenty of supplements you can use to help things along.
Take some fish or bone meal powder, or pelleted fertilizer, and sprinkle it over the straw bale before you start watering (detailed in the next step).
Water Your Straw Bale
Watering your straw bale will speed up the decomposition process, which will create compost for your potato plants to use for nutrition as they grow.
You should water the straw bale every day for at least a few days. It may take several minutes of watering, to soak a straw bale, especially in hot, dry weather.
If you have lots of straw bales, it could take half an hour or longer to water each day! To save time, you can set up soaker hoses and turn them on and off at the same time each day.
Watering your straw bales will get the composting process off to a good start. You’ll know it’s working when you feel the inside of the straw bale starting to heat up – it can get up to 125 degrees Fahrenheit!
It is tempting to get started with your garden quickly. However, you need to resist the temptation. Make sure to wait 2 weeks after the initial watering before you start planting.
If you plant too early, the straw bale may be too hot for your seed potatoes, which will damage or kill them! Use a thermometer to test the temperature inside the straw bale – it should be 75 to 80 degrees Fahrenheit (24 to 27 degrees Celsius) consistently before you plant your seed potatoes.
Planting Seed Potatoes in Your Straw Bales
When the straw bales have been properly positioned, fertilized, watered, and composted, you are ready to plant! All you need to do is get your seed potatoes, prepare them for planting, and put them in the straw bale.
Gather or Buy Your Seed Potatoes
You can buy sprouted (seed) potatoes online or at a local garden center. You can also use sprouted potatoes that you have at home. If you leave potatoes in a warm, damp, well-lit area, they will sprout quickly (each sprout is called an eye).
The eyes use the starches inside the potato to grow. They will eventually grow green leaves, if given enough time, but you don’t need to wait that long before planting them.
Cut Your Seed Potatoes into Pieces
You can plant entire potatoes all at once, if you wish. However, you can get more potato plants if you cut your seed potatoes into pieces.
Just make sure that there is at least one eye on each potato piece that you cut. Also, leave the cut potato pieces out for a few days to dry out before planting them.
Plant Your Seed Potatoes
Finally, all of your preparation is complete – it is time for planting! First, pull away some of the straw and composted material to form a hole to just about the bottom of the straw bale.
Then, put the seed potato piece at the bottom of the hole. Cover the seed potato with 4-6 inches of straw and composted material.
Caring for Your Straw Bale Potato Plants
Now that your seed potatoes are planted, you will need to care for them until they produce green growth above ground and potatoes underground. Proper care includes watering and fertilizing as needed, and “hilling” the straw to keep the potatoes covered properly to protect them from the sun.
Water Your Straw Bales Often
Continue to water your straw bales often, to keep your potato plants alive. Just as potato plants in dirt can die from dehydration, so will straw bale potato plants.
As mentioned earlier, you can use drip irrigation to save yourself time. You can turn the water on and off at the same time each day, although you may need to make adjustments, depending on heat waves or rainstorms.
If you are forgetful, you might be better off using a hose with a spray attachment, so that you can control the amount of water that each straw bale gets.
It is possible to over water, so be careful and pay attention! For more information, check out my article on over watering your plants.
Add Fertilizer during the Growing Season
During the growing season, you can use the same fertilizers mentioned above (bone meal, fish meal, or pelletized fertilizer). Simply sprinkle some onto the straw bales, and water it in so that it can soak through to the potato plant.
Just be careful about over fertilizing, or else you can burn your plants with excessive nitrogen or salts. For more information, check out my article on over fertilizing your plants.
Use “Straw Hilling” to Keep Potatoes Covered
When growing potatoes in soil, you will want to keep adding soil to cover the plant (except for the top). This “hilling” method keeps the potatoes from being exposed to sunlight, which produces solanine, a compound that makes the potato appear green, and is toxic to humans.
You can apply the same principle (“straw hilling”) when growing potatoes in a straw bale. Every 6 inches or so of growth, add some straw to cover the potato plant, except for the very top part (the leaves on top still need exposure to sunlight for photosynthesis and growth).
Harvesting Your Straw Bale Potatoes
When your potato plants start flowering, you can start harvesting the older potatoes, which are found at the bottom of the straw bale.
When the potato plants start dying back, wait 2 to 3 weeks. At that point, the plant is done growing, and you can start harvesting the potatoes.
Pull out straw and compost (decomposed straw) to find the potatoes. Clean off the potatoes, and let them dry out. Then, store them in a cool, dry, dark place to prevent them from sprouting.
Cleaning Up Your Straw Bales at the End of the Season
Gather up all of leftover straw, composted straw, and dead potato plant leaves and stems from the season. Then, add all of it to your compost bin or pile.
You can use the compost next year for traditional gardening, or for potted plants that you grow indoors. For more information, check out my article on how to make compost.
Straw bale gardening is an easy method for growing potatoes, with less dirt and mess than traditional soil gardening. As an added bonus, you can compost the remaining straw and organic material at the end of the season.