The Best Plants to Grow in Straw Bales
The great thing about straw bale gardening is that you can grow just about anything in a bale that you can in the ground. In fact, if your garden has very poor soil, this method is a perfect match for you. However, some plants grow better in bales than others. In this chapter, you’ll learn which vegetable crops and fruiting plants grow best in straw bales, how many of each to plant per bale, as well as some helpful tips for a thriving vegetable garden.
Fruiting Plants
From tomatoes and strawberries to beans and cucumbers, fruiting plants are some of the best plants for straw bale gardening. Here are our top picks.
Tomatoes
Tomatoes are a relatively costly fruit to buy, so trying to grow them in your garden is always tempting. In fact, there’s a good chance you decided to pick up gardening simply to grow your own. They are a fantastic choice for growing in straw bales, and you may even find the process easier than growing them in soil.
Growing tomatoes in bales of straw has several benefits. The heat of the composting process helps keep the tomato plants warm during the start of the growing season. The decomposing bale provides a nutrient-rich growing medium, and the moist straw acts as a mulch, preventing water loss in the heat of summer.
How to Grow Tomatoes in Strawbales
Tomatoes are a warm-season crop, and their seeds need a temperature range of 70° to 80°F (21° to 27°C) to germinate. In cooler climates, it’s best to sow them in pots indoors, then transplant to the bale when seedlings are at least 6 inches (15 cm) tall and outdoor temperatures are above 60 °F (15 °C). In warmer growing zones, you can sow tomato seeds directly into the bale.
Always make sure that your tomato plants receive 6 to 8 hours of sunlight each day. A straw bale garden positioned in full sun would be perfect. Make sure that the plants receive consistent moisture by watering them regularly or using a soaker hose, and remember to use an organic fertilizer once every two weeks when they start fruiting. Tomatoes also benefit from supports, especially vining varieties or those bearing heavy fruit. Stakes work best, although you can also use cages for vine tomatoes.
Best Tomato Varieties for Straw Bale Gardening
The best type of tomato to grow depends on how you plan to harvest it. If you want a steady supply throughout summer and early fall, indeterminate tomatoes (such as cherry tomatoes) are a great pick. If you want to harvest everything at once and preserve it for later, go for determinate varieties.
Here are some great tomato cultivars to grow in your straw bale garden:
- Sungold: a golden cherry tomato that’s easy to grow and tastes extra sweet;
- Black cherry: a great way to combine juicy sweetness and ornamental value;
- Carmellos and stupices: wonderful mid-sized varieties that won’t overwhelm your straw bales;
- Beefsteak and Brandywine: large, meaty tomatoes, perfect for sauces.
Eggplants and Peppers
Eggplants and peppers are related to tomatoes, and growing them in a straw bale garden has similar requirements. Unless you live in a warm climate, sow them indoors at least 6 weeks before the last frost. These plants like hot weather and plenty of sunlight to grow, and will need a steady supply of water and fertilizers. Eggplants will also need stakes to help support the weight of the fruit.
On average, peppers are ready to harvest after 3 months, but chilies and hot peppers will take up to 5 months before they’re fully ripe. Eggplants need around 4 months from seed to harvest, but some Asian varieties can be picked as early as 50 days after sowing.
Zucchini, Cucumbers, Squash, Melons
Also known as cucurbits, these plants love warm weather, humidity, frequent watering, and climbing. Plant your cucumbers, zucchini or summer squash in the straw bales in mid-spring, or start them from seed indoors 3-4 weeks before moving them to the garden. Make sure to provide them with stakes and supports, otherwise they will sprawl beyond the bale and into your garden path. Once they start flowering, give them an organic fertilizer that’s rich in phosphorus and potassium but low in nitrogen.
One helpful tip that will ensure a bountiful harvest is regularly pinching the side vines. This way, the plants will branch out, creating more vines, which then create more flowers and – you guessed it – more fruit. You can also try manually pollinating the flowers, especially if you live in an area with very humid summers or if your’re growing vegetables in a greenhouse.
Strawberries
This is a fantastic treat to have growing in your bales — they don’t call them straw-berries for nothing. For best results, choose a variety that doesn’t produce many runners. Day-neutral and everbearing strawberries are ideal, whereas June-bearers produce the most runners.
How to Grow Strawberries in Straw Bales
Start with a straw bale that’s positioned in full sun. Strawberries need at least eight hours of sunlight per day to produce large, sweet fruit. You can plant them in March or April, after the last frost has passed. Planting three to four strawberries per bale will give them enough space to develop nicely. Water the bales regularly, and give the plants a nutrient boost with a balanced fertilizer. Strawberries take around 3 months to grow fruit, but will produce a larger harvest the second year.
Strawberries are perennials, meaning they come back each year. When growing them in straw, you can keep them in the same bale for a maximum of two years, before the bale decomposes entirely. You can then cut some of the established runners at the end of the growing season and transplant them to a new bale.
Legumes
Legumes or podded vegetables are a must-have in any garden and will develop wonderfully in your straw bales. They are easy to grow, harvest, and store, and the fact that their roots fix nitrogen into the soil means that they don’t need too much fertilizer. Beans and peas are the most common plants grown, but you can also use your straw bales for lentils and chickpeas.
For an abundant harvest, legumes need at least 6 hours of sunlight per day, so plant them in an area with full sun. Beans are sensitive to frost and are best planted in mid-spring at the earliest. Peas, lentils, and chickpeas seedlings can tolerate a light frost, but are best planted in early spring. With the exception of Lima beans, most legumes will struggle to grow in very hot climates, and may drop their flower buds from heat stress.
All legumes are natural climbers, so you’ll need to provide them with supports. Trellises are a great choice for shorter varieties such as bush beans, green beans, peas, and lentils. Taller vines such as pole beans and runner beans will need tall metal stakes or canes to keep them from falling over.
Roots and Tubers
Root vegetables and tubers are two great and low-maintenance options for straw bale gardening. The loose and aerated structure of the straw, paired with its moisture-retentive properties, makes it a fantastic growing medium. Also, root crops are far easier to harvest from straw bales than from soil – just wipe off the damp straw and you’re done.
Carrots, Parsnips, Celeriac
Carrots come in many colorful varieties, from classic orange to white, yellow, and purple. Parsnips, celeriac, and even parsley root are not to be dismissed either. Sow them in early spring in a sunny part of your garden, and make sure to keep their straw bales moist. Parsnips benefit from a light frost, which makes them taste sweeter, so you can leave them in the bale well into winter.
Growing Carrots in Straw Bales
Sow your carrot seeds directly in the straw bale in mid-spring, then thin out the plants when they’re about 3 inches (7.6 cm) tall. Ideally, you’ll want to thin them out when the straw is damp, to avoid disturbing the roots too much. This will prevent issues with twisting and forking, and ensure that the roots are growing nice and straight.
Carrot roots bruise easily, so avoid using sharp tools such as a garden trowel to dig around them. Once bruised, they can easily attract carrot flies, and that’s your crop gone. Try doing your weeding by hand, and plant onions and carrots together to protect them from the carrot fly. Also, go easy on the nitrogen fertilizer. Instead, use an organic fertilizer rich in potassium and phosphorus, which promotes healthy root growth.
Potatoes
Everyone’s favorite tuber, potatoes are perfectly suited for straw bale gardening. If you’ve ever grown potatoes in a bag of soil, you may find the process similar, yet decidedly easier – especially if you’re not a fan of digging.
How to Grow Potatoes in Straw Bales
Start by planting your potatoes 4 to 6 inches (10 to 15 cm) deep inside the straw bale, spaced out at about 10 to 12 inches (25 – 30 cm). Small potatoes can be left whole, while larger ones can be halved or quartered, leaving one “eye” on each piece. Cover them well, as any amount of sun will turn the tubers green and inedible.
As the potato shoots grow, you’ll want to cover them with more straw when they reach 4 – 6 inches tall. Repeat the process for the next 3 to 4 months, making sure that the bale is kept evenly moist. Early-maturing varieties such as Yukon Gold or Red Pontiac can be harvested 80 days after planting. Meanwhile, purple potatoes can take up to 120 days to be ready. At harvest time, simply dismantle the bale, dig out the potatoes by hand, and add the remaining straw to your compost pile.
When growing potatoes in straw bales, you may notice that the bale loses its shape as you pile up the straw and as the roots start pushing at the sides. You can use wire fencing to reinforce the bales. Or better yet, make a wooden frame for the bales, similar to what you’d use for a raised bed vegetable garden. 
If all this still seems a bit complicated, you can try growing sweet potatoes in straw bales instead. They are a vining crop so you won’t need to worry about constantly piling straw on top of the new shoots. You can buy sweet potato slips from garden centers or make your own by half-submerging the potato in water. Plant the slips directly in the straw bale, in full sun, water regularly, and you can harvest sweet potatoes after about 4 months.
Cruciferous Vegetables
Crucifers (or Brassicas) are one of the best vegetables to grow in straw bales. The straw provides a soilless growing medium that protects them from the dreaded clubroot disease. Meanwhile, the moist, nitrogen-rich bale will ensure a steady harvest from early summer until early winter.
Cabbage
Cabbage is a cool-season crop, best planted in a spot that gets at least 6 hours of full sun each day. Ideally, you’ll want to plan your sowing to harvest it before the heat of summer sets in. Otherwise, it will bolt and turn bitter. In USDA hardiness zones 3 to 6, you can sow it from March until September. In hotter climates, you can sow it as early as January, and harvest it by the beginning of spring.
Cauliflower and Broccoli
Cauliflower and broccoli are great in-between-season crops that can be harvested until at least the start of winter. Plant them in late spring, give them access to full sun, keep their bales moist, and you’ll enjoy a delicious and healthy food well into the winter. These plants grow best when the straw bales are treated with plenty of nitrogen-rich fertilizer.
Turnips, Radish and Kohlrabi
Straddling the line into the root vegetable category, turnips, radish, and kohlrabi grow so fast you can even harvest two crops the same year. Plant one batch in early spring, harvest them by early summer, then plant a second batch in early fall. Avoid sowing them in summer, as the intense heat will only make them bolt. One way to mitigate intense heat is by planting them in partial shade.
Sow your turnips, radishes, and kohlrabi in full sun to encourage large roots, and thin them out 3 weeks after the seeds have sprouted. Radishes can be harvested in as little as 30 days if they get more than 6 hours of sun per day. For the others, wait around 7-8 weeks before harvesting. Try picking them before they fully mature, to avoid them becoming too bitter.
Asian Greens
Add an exotic touch to your straw bale garden by growing Asian greens such as gai lan, bok choi, yu choi sum, and even Chinese cabbage. They have the same growing requirements as regular cabbage and will bring a unique flavor profile to your table.
Leafy Greens
Leafy greens, like root vegetables, are easy to grow and perfectly suited to straw bale gardens. Here are some that are worth a shot.
Lettuce
The classic salad green, lettuce can be planted in both spring and fall. For uninterrupted harvests, you can sow new seeds every two weeks. When you grow lettuce in straw bales, keep in mind that this crop loves a constant supply of compost and nitrogen-heavy fertilizers, so add some to the bale 2-3 weeks after each planting.
Spinach, Kale and Chard
This tasty trio is easy to grow and requires minimal maintenance. Spinach, chard, and kale can grow well into the chilly months, and really help you make the most of the space your straw bale garden has to offer. Plant spinach and kale in the early spring and then again in the fall, as they tend to lose their delicious flavor when summer heat sets in. Chard is the most versatile of the three, and a spring planting will keep you busy harvesting until the first frost.
Alliums
Onion, garlic, leeks, shallots, and chives are a staple ingredient in most recipes, and definitely deserve a spot in your straw bale garden. They don’t take up too much space either, and the nitrogen provided by the decomposing bales will promote an abundant harvest. All alliums need at least eight hours of direct sunlight each day, so try positioning them in the part of your garden that gets the most sun exposure.
Herbs
Growing your own flavoring and garnish makes the gardening experience all the more fulfilling, and herbs are just as simple to plant and harvest as leafy greens. Whether it’s parsley and cilantro (or coriander), thyme and rosemary, or basil and oregano (the Italian seasoning dream team), always make sure to leave some room for herbs in your garden.
Companion Planting
No straw bale garden would be complete without companion plants. These are your top allies on an organic farm, attracting pollinators such as bees and butterflies, and pest-eaters such as lacewings and ladybugs. Marigolds and nasturtiums help keep aphids off your vegetable plants and will look absolutely dashing while doing it too. Geraniums and certain herbs such as thyme, basil, and mint contain fragrant oils that deter bugs, as well as flies and mosquitoes.
How Many Plants Should You Plant Per Bale?
The plants you choose will determine how many you can grow in each bale. The seed packet should give you a guide to spacing but, if in doubt, more space is always better. Keep in mind that, when growing vegetables in straw bales, you should never plant them up to the edge of the bale. On average, a single bale can fit up to two horizontal rows to facilitate healthy plant growth.
Here is a rough guide you can use to plan your bales.
| Two plants | Three plants | Four plants | Five plants + |
|---|---|---|---|
| Corn (dwarf) Squash Melon | Tomato Eggplant Zucchini Chard | Pepper Cucumber Cabbage Garlic Beet Carrot | Pea Bean Radish Annual flowers Lettuce |
Plants That Don’t Do Well in Straw
Luckily, the list of plants that are not suitable for straw bales is quite short. Top-heavy plants like corn are not a good choice, as the bale might break apart under their weight. Tall plants such as pole beans are also at risk of toppling over in strong winds if their supports are not firmly secured in place.
If this is your first attempt at straw bale gardening, try keeping things simple. Start with a few straw bales and grow tomatoes, peppers, lettuce, dwarf beans, radishes, and herbs. This will give you a better idea of how fast the bales break down, how the plants grow as the season progresses, how much water your bales need, and so on. You can then use your knowledge to grow more challenging crops such as strawberries and pumpkins the following year.
Ready to Start Planting
Now that you’ve picked your plants, it’s time to start planting. In chapter 5, you’ll learn how to plant in a straw bale garden, how to keep your plants healthy as they grow, and what to do when the fruits (and vegetables) of your labor are ready for harvest.
