How to Plant in Straw Bales: Great Tips for a Great Harvest
After preparing your straw bales, it’s time to start sowing your plants and tend to them as they grow. In this chapter, you’ll learn how to decide whether potting or direct planting is a better fit for your garden bales, how to keep your plants healthy as they grow, and how to harvest different types of vegetables in a straw bale garden.
When to Start Planting Vegetables in Straw Bales
There are many types of fruiting plants and vegetables you can plant using the straw bale method, each with its own growing requirements. As a result, the one-size-fits-all approach is not ideal. For example, in warm climates, you can sow tomatoes as early as January. But in cooler climates, it’s best to wait until March.
The easiest way to decide is by checking out our garden planner. Just pick your local growing zone (we have maps for the United States as well as Europe), and depending on what you’re planning to grow, you’ll instantly know when to start planting seeds and when to harvest your crops.
Planting in Straw Bales – Two Methods
To start your straw bale garden, you can either sow seeds directly in the bale, or you can start the seeds indoors, in pots, then transplant them to the bale later. Let’s take a closer look at each method.
Sowing Directly in Straw Bales
After you have finished conditioning your straw bales, you’ll notice that the top of the bale begins to break down and look a bit like compost. This growing medium is rich in nutrients, yet not enough to sustain seed germination. Therefore, you’ll need to add a bit of actual soil to the bale.
Potting soil or a seed-starting mix are two excellent choices. Whatever you do, avoid adding ordinary garden soil to the straw bale. The soil from your garden can contain pests, weeds, and even diseases, and it would be a shame to waste all your hard work by contaminating the bales this manner.
There are two ways to add soil to straw bales, depending on what you’re planning to grow.
Create a Raised Flatbed
Make a mixture of potting soil and compost and spread it on top of the bale. Make sure it’s evenly spread out, but keep the layer thin. A thickness of one or two inches (2.5 – 5 cm) should be enough.
This method works best if you’re growing a lot of plants per bale. Use it for vegetables such as lettuce, carrots and parsnips, onions and garlic, or smaller plants like radishes, chard, spinach, or herbs. Spread the seeds on the planting surface according to the instructions on the packet, and give the straw bale a good soak. After the seeds sprout, remember to thin out the plants when they reach about 2 inches (5 cm) in height, or when they have two sets of true leaves.
Dig Holes in the Bale
This method requires less soil and compost, and works best if you’re only sowing a few plants per bale. Using a garden trowel, dig a hole in the bale about 3 inches (7.6 cm) deep and fill it with soil, then repeat the process for each seed you’re planning to grow. Remember to check the spacing requirements on the seed packet and leave enough space between the holes. Then simply push each seed in the hole, cover it with soil, and water the straw bale thoroughly.
You can use this method for growing cucumbers, tomatoes, strawberries, beans, as well as root crops.
Transplanting Seedlings to the Straw Bale
In cooler climates, you may want to kick-start your straw bale garden by sowing vegetable seeds indoors then planting seedlings into the bale when the weather gets warm enough. Simply follow the instructions on the seed package and sow your seeds at least 4 weeks before the last frost.
The trick to transplanting vegetable seedlings from pots is making sure you don’t break their delicate roots. You can easily prevent damage to the plant roots by sowing in compostable seedling pots. This way, when it’s time to transplant, you can simply put the entire pot in the straw bale, without having to take the plant out first.
Your plant seedlings are ready to be transplanted when they have at least two pairs of leaves and outdoor temperatures have risen sufficiently. Use a garden trowel to dig a hole in the straw bale, put the plug plants in, and add a bit of compost or potting soil mix to cover any exposed roots. Water your seedlings immediately, to ensure that they establish faster.
If you’re transplanting solanaceous crops such as tomatoes, peppers, and eggplants, always make a hole that’s deep enough to get all of the roots and an inch of the stem into the bale. These plants have tiny hairs on their stems called adventitious roots, which can develop into roots if they come into contact with a growing medium. This will result in plants with a stronger root system, which gives them more stability as they grow.
How to Care for Plants Growing in Straw Bales
Once your plants are settled into the straw bale garden, you’ll have to perform a few maintenance tasks to help them grow. Just like in a soil-based garden, they’ll need regular watering, fertilizers, weeding, and perhaps a helping hand dealing with pests.
Watering and Fertilizing
Straw bale gardens require a lot of water because straw dries out quicker than regular soil. Young plants in particular need plenty of moisture until they become established. A good rule of thumb is to keep watering until water leaks out of the bottom of the bale, then water again when the straw no longer feels wet.
Depending on your climate, you may need to water as often as once per day. However, installing a simple irrigation system and a timer can ensure that you will water regularly without putting in too much work.
When it comes to feeding your vegetable crops, an organic fertilizer is ideal. Try using seaweed mixes, worm castings or compost teas, or even a pre-mixed liquid fertilizer. Generally speaking, younger plants can be fertilized once a week for the first month or so. Afterward, as the straw bale slowly turns to compost, you can reduce the fertilizer doses to twice a month.
Always check the fertilizer requirements for each plant, as they will need different nutrients. Leafy greens, root vegetables, cabbage, cauliflower, herbs, and plants such as onions and leeks need a nutrient-rich fertilizer. Carrots and potatoes also benefit from a potassium boost. On the other hand, giving fruiting plants too much nitrogen can result in lots of leaves and vines, and very few flowers. Instead, you’ll want to use a fertilizer that’s rich in phosphorus when plants begin flowering in order to encourage a large harvest.
Straw bale gardening makes weeding easier than in a soil garden for three reasons. First, you’ll find that far fewer weeds make their way into the bale. Second, straw has a loose structure, which makes pulling out weeds easier. Last but not least, the fact that the bale is essentially a raised bed means that weeding is far kinder on the knees and back.
Of course, you can prevent weeds in the first place by creating a barrier between the soil and the bottom of the bale. Try placing your straw bales on top of cardboard, a fabric or plastic membrane, or better yet, concrete or gravel.
If you do find weeds growing in straw bales, it’s best to just remove them by hand. Pull them out from as close to the base as you can, and make sure that the roots come out as well. To avoid weakening the bale or disturbing the vegetable roots as you weed, try placing one hand on the bale at the bottom of the plant, and use the other hand to pull out the weeds. Also, remember that prevention is the best cure, so try to remove them when they’re still small.
Pruning and Maintenance
Regular pruning keeps your plants healthy and also encourages a higher yield. Keep an eye out for any leaves and stems that look wilted, damaged, discolored, and trim them using gardening scissors. You’ll also want to remove any fruit that looks bruised or rotting. It’s a good practice to disinfect your pruning tools between use, to prevent spreading pests and diseases from one plant to the other.
If you’re growing vining plants such as beans, cucumbers, or squash, pruning them is a must. Once the plant is about one foot (30 cm) tall, you can start trimming the side vines. This will make the plant bushier, and it will also encourage it to spend its energy on flowers rather than growing leaves and stems.
Using straw bales for growing vegetables is a great way to protect them from pests. This isn’t to say that they’re completely pest-free. Yet if your aim is organic gardening, you’ll want to steer clear of industrial pesticides. Instead, try using a neem oil solution to prevent pests such as aphids, whiteflies, cabbage worms, even snails. You can use a mixture of water and Castile soap to kill pests without damaging the plants.
Also, remember to use companion planting to your advantage. Annual flowers such as nasturtiums and marigolds are an effective way to keep pests away from your straw bale vegetable garden.
How to Harvest From Straw Bales
Harvesting is the best part of the gardening process. And, luckily, harvesting from straw bales is not too different from harvesting from a regular soil garden. Fruiting plants such as tomatoes, peppers, cucumbers or beans can be cut from their stems using gardening shears. Leafy vegetables and plants such as cabbage or kale can just be picked from the bale when they’re ready.
The only vegetables that need a slightly different approach are root crops and tubers.
Harvesting Potatoes From Straw Bales
Potatoes grow deep inside the straw bale, so you’ll need to do a bit of digging. The easiest approach is to dismantle the entire bale. Cut the twine, then manually separate the bale layer by layer, picking up the tubers as you go along. You can also use this method for harvesting sweet potatoes. When you’re done, give the straw one final root through, in case some of them got lost during the process.
Harvesting Root Vegetables
The best way to harvest root crops such as carrots, beets, parsnips or horseradish is to simply pull them out of the straw bale by hand. By the time they’re ready, the bale should have a loose consistency, so you shouldn’t even need to use a trowel. This way, you’ll also prevent accidentally damaging them.
How to Reuse and Recycle Your Straw Bales
Most straw bale gardens have a lifespan of about a year. By the time your crops are harvested and the growing season is over, the bales will have started breaking down. However, that doesn’t mean they don’t have any other uses. And, depending on where you live, you may even get a chance to reuse them for a second season.
In cooler climates, straw bales can be used for up to two years. If they’re still holding their shape, you can reuse the ones that grew leafy vegetables or fruiting plants. Simply leave them outside over winter, and plant them again in spring. This should slow down the composting process and prevent them from breaking down too much in the meantime. Alternatively, you can try reinforcing them at the sides using wire mesh, or for something extra sturdy, build them a wooden frame.
If you have a greenhouse, you can even reuse the straw bales to grow winter vegetables such as cabbage, Brussels sprouts, spinach, or Asian greens. Remember the bales are heavy when full of water, so give them a week or two to dry out under a tarp before moving them
Straw bales used for growing root crops will probably look a bit worse for wear even after one year. Similarly, harvesting potatoes will make the bale too loose for reuse. In such cases, it’s best to either add the bales to your compost pile or use the straw as mulch.
In warmer climates, the heat makes the bales decompose faster, which means you can only use them for a year before they completely fall apart. On the plus side, if you plan your gardening schedule right, you’ll be busy sowing and harvesting from January until late December.
But once the year draws to an end, it’s time to retire your bales to the compost heap. They should still contain enough nutrients and beneficial bacteria, which can be used to support next year’s vegetable garden. Simply add the used straw bale to your compost pile, keep the compost moist, and use a garden fork to turn the pile frequently until it breaks down.
Try It Yourself
If you love growing your own but don’t have the space or the right soil for a productive vegetable plot, straw bale gardening is definitely worth a try. Beyond the initial two weeks of preparation, you should find yourself with minimal weeding and pests to deal with. Instead, you can enjoy growing and harvesting nearly any plant you choose in a container that is entirely natural.