How to Build a Straw Bale Garden

Once you’ve compiled your supplies, you’re ready to learn about how to plan a straw bale garden. In this chapter, we’ll discuss how to pick the right spot for your bales and plants, how to create the best layout and how to prepare the site for watering and growing vegetables. Simply follow our 8 steps below and build a great straw bale garden!

Step 1: Know When to Start

Let’s begin with the most important question: When should you start your straw bale garden? Depending on your growing zone, it could be either fall or spring.

Fall

Fall is a good time to start your straw bed garden if you live in an area with long winters and cold springs. Straw bales are also easier to source this time of year, once farmers are done harvesting their cereal crops.

Spring

Spring is usually the best choice for setting up your bale garden. Most vegetables are also best planted this time of year. If you live in a warm area, the bale composting process can take as little as two weeks, which gives your growing season a significant head start.

Before you begin with your preparation for straw bale gardening, always wait until the last frost has passed. The date will vary from one growing zone to another, so make sure to check what applies in your area. For example, in USDA hardiness zones 5 to 7 the last frost date is typically around mid-April, while in zones 1 to 3 it can last up until the end of May.

Step 2: Find the Right Spot for Your Straw Bales

Next, you’ll need to set up a straw bale garden in a way that provides the best conditions for the straw to decompose and your plants to grow. Let’s start with the basics.

Where to Put the Bales

In any vegetable garden, the main factor that decides what kind of vegetable crops you can grow, and where, is sun exposure. But when using the straw bale method, sunlight plays an even more important part. Here’s what you need to know.

Full Sun

Any part of your garden that receives at least six hours of direct sunlight per day is considered an area with full sun. This is ideal for growing vegetables and fruit that need lots of sun to grow, such as strawberries, tomatoes, eggplants, peas, beans, cucumbers, and other vine crops. Not only that, but most straw bale gardens perform better in full sun. The heat makes the bales decompose faster, allowing you to start planting seeds sooner and giving you a longer growing season.

A spot that gets access to morning and noon sun would be perfect for straw bale gardening. This will also prevent the straw bales from drying out too fast. A garden with southern or western exposure works as well, but you’ll need to stay on top of your regular watering schedule.

Partial Sun

Sometimes referred to as partial shade, this is an area of your garden that receives 3 to 6 hours of sunlight per day. Partial sun is ideal for crops that don’t need too much sun exposure, such as carrots and other root crops. Leafy vegetables such as cabbage and salad, or herbs like basil and arugula (rocket) also benefit from partial shade, which prevents bolting and a bitter taste.

Most gardens have access to partial sun, often as a result of neighboring trees or shrubs, and even buildings. If you want to start straw bale gardening on your balcony or deck, chances are it will also be sitting in partial shade. This shouldn’t be a problem, although the bales will take longer to decompose.

Full Shade

If your garden receives less than 4 hours of sunlight per day, it’s sitting in full shade. Of course, this doesn’t mean complete darkness. However, covered porches, large trees, and even tall buildings can drastically limit the amount of light your plants receive.

Full shade is not ideal for straw bale gardening. Your bales will take a very long time to break down, your vegetable seedlings will struggle to grow, and you may even encounter problems with rot.

What to Put the Bales on Top of

In addition to considering the amount of sun your plants need, you’ll also want to choose an appropriate surface for your straw bales.

In a garden, you’ll typically have three choices: soil, grass, or concrete.

Soil

If you have an empty patch of earth in your garden, simply place your straw bales on top of it. This works really well if your garden has heavy clay soils that are difficult to break up, or would need a lot of soil amendments to yield crops. The downside is that can leave the bottom of the bale exposed to pests.

Grass

Like soil, grass can be used as a base for your straw bale garden. Yet this also leaves the bottom of the bale exposed to pests and weeds. We’ll discuss how to handle that when we get to Step 4.

Concrete

Concrete is ideal because it’s a naturally flat surface that is impervious to weeds. Also, it prevents the bottom of the bale from staying damp, which limits the risk of mold and rot. If you don’t have a concrete base for your straw bale garden, you can use an area that’s covered in gravel or paving slabs.

Balcony, Porch, and Deck Gardens

For straw bale gardening on a balcony, porch or deck, building a frame for your straw bale is a must. You can use pressure-treated garden lumber, and also place caster wheels underneath the straw bale. This will increase its maneuverability in case you need to move it to another spot.

Building a deck-based straw garden also relies heavily on providing proper drainage and air circulation. Ideally, your straw bale should sit on top of metal or wood slats, which should keep the bale raised by at least an inch. This way, you’ll prevent issues with the deck or porch rotting due to excess moisture.

Step 3: Pick a Layout and Design

Once you’ve found a spot, it’s time to think about your straw bale garden plant layout. The design of can be as creative or simple as you wish. The most important thing is leaving enough space between them to water, trim, weed, and harvest your produce.

If you’re growing in an open space, like a garden or a backyard, leave a gap that’s wide enough for you to walk through. If your bales are placed directly on top of the grass, leave enough room for your lawnmower to pass through.

The location and amount of space you have will determine the best design for your straw bale garden.

An open space garden provides a wide planting surface and gives you plenty of room to experiment. If you’re just getting started, you may find the row design works best for straw bales. This also allows you to organize your vegetables by types, such as root crops, climbing plants, and herbs. Or feel free to play around with complex designs, such as stacking your raised beds in a step design, or positioning bales into a square block with flowers on the inside and veggies on the outside.

Porch, patio, and deck gardening: try covering the sides with screening or wooden slats, and maybe paint them in vivid colors and patterns for an artistic touch. If you want to keep things simple and also protect your deck from moisture, you can also place the bale in a metal feeding trough.

Balcony: to save up space, you can try tying a bale with string and hanging it on the inside of your balcony rail. This will also help with drainage and air circulation, keeping the bottom of the bale from going mushy.

Step 4: Prepare the Ground

If your straw bales are sitting on top of soil or grass, you’ll need to prepare the base before putting the bales in place.

Unlike traditional soil gardening, straw bale gardening allows you to leave the ground as is. But if your property is rife with pests like moles and groundhogs, you can lay galvanized bird wire beneath the bales so diggers don’t destroy your hard work.

If you’re placing the straw bale on top of grass, the lack of sun and the heat resulting from the decomposing bales will kill it in time. However, you’ll want to protect your straw bale from weed seeds. The easiest way to prevent weeds from sprouting is by placing a protective layer between the grass and the bottom of your bale. Cardboard is a cheap and easy to find material, but you can also use landscape fabric, burlap, or plastic sheeting.

Step 5: Place Your Straw Bales

Your straw garden beds can be placed in any design that allows you adequate access to your plants. The trick that makes all the difference is placing the bales the right side up.

You may be surprised, but there is a right and wrong way to place your straw bales down. Let’s start by taking a look at the dry bales. You’ll notice that one side has the cut ends of the straw stalks poking out. Usually, this is the narrow side of your bale. On the other sides you’ll notice the stalks laying flat or folded.

The side with the cut end is the one you want facing upwards. This way, the straws tubes will transport the water inside the bale and to the roots of your plants. If you place the bales with the flat side pointing up, the water will drain off the straw, and the bale will dry out faster.

Step 6: Make a Path

After your bales are in place, adding a garden path is a great way to provide both functional and decorative features. Here are some materials you can use.

Mulch or wood chips work great at keeping weeds at bay, and are a great low-maintenance way to add interest to your garden. They’re soft to walk on, which is particularly beneficial for bale gardens placed on concrete. Use fabric or a plastic membrane for an extra level of protection and to make sculpting the path easier. To learn more about producing your own mulch and wood chips, check out our review of the best chipper shredders.

Straw itself can also be used to line your garden path. It’s soft on the feet and blends in well with your bales. As a bonus, it also helps deter weeds from your garden.

Gravel or stone is an excellent choice for those after a more organized, upscale feel. Unlike mulch, which has a typical lifespan of 3-5 years, it lasts forever, and doesn’t get soggy.

Step 7: Add Supports

Once you smooth out an easy-to-use path, it’s time to think about adding supports for your vegetables. Whether or not you need them will depend on the type of plant you’re growing.

Which Types of Vegetables Need Supports?

Top-heavy plants need supports by default. This includes fruiting shrubs such as raspberries or currants, and taller plants from the nightshade family, such as tomatoes and bell peppers. Beefsteak tomatoes and globe (or American) eggplants, in particular, can become very top-heavy once they start fruiting. Stakes provide the best support for these plants, but you can also use wire cages if the space allows it.

Vine tomatoes, such as cherry tomatoes, will always need supports unless you want them hanging over the side of the straw bale. Cages, trellises, and standard stakes work perfectly. Keep in mind that, despite the name, vining tomatoes aren’t actually climbers, so you’ll need some string or twine to secure them to their supports.

Peas and beans are natural climbers and, unless you’re growing dwarf varieties, they will need a tall support to wrap around. For most varieties, wire or wood-based walls work fantastically, but stakes, tepees, and trellises will keep them standing up too. 

Vine vegetables like melons, cucumbers, squash, and zucchini (courgette) love to climb, and they also produce heavy fruit. For vegetables with thinner skin, such as zucchini or garden cucumbers, you’ll also want to keep them elevated, so that they can ripen without blemishes. Cages work best for melons and squash, while cucumbers will happily grow on a trellis.

Best Supports for Your Plants

Many materials can be used to create DIY supports for your straw bale garden. Branches made from everything from willow to bamboo create an earthy and sturdy support system. Plastic fencing or metal stakes, on the other hand, are the most permanent staking solution.

Stakes are easy to implement, and you’ll need one for each plant. Ideally, you’ll want to set them in the straw when the plants are still small, to avoid damaging the roots.

Trellises are also easy to set up, although it’s best to position them before the plants start climbing. For vining tomatoes, make sure to have some string handy, to help secure the plants to them.

A tepee-shaped support is a great alternative to trellises, especially if you have stakes or branches going spare. The downside is that they take up a lot of space and, depending on the size of the plant, you will only be able to fit a maximum of two per straw bale.

Depending on their size, cages can be set in place as soon as the plant has reached a height of at least 4 inches (10 cm). Remember to factor in the size of the plant once it reaches maturity, and build a cage that fits. For example, eggplants can easily reach a height of 3 feet (90 cm), while pumpkins can spread over a width of up to 5 feet (1.5 meters).

Alternatively, you can also place your straw bale garden next to a tall, flat surface such as a fence or a wall. Attach some hooks or nails to the surface, then simply run some string between them for an easy DIY trellis.

Step 8: Install a Watering System

Watering can be a chore to begin with, but with straw bale gardening, you’ll need to water fastidiously especially in the beginning.

Straw has a looser structure than soil, so water runs through it faster. Like compost, straw is decomposing as the season progresses. This creates heat, so water is lost more quickly that way. Finally, air circulation within the straw bales also allows water to evaporate faster.

Brand-new straw bales will need frequent watering while you condition them. In hot, dry climates, you may even need to water them more than once a day. Here are a few options that will make your job infinitely easier.

Use a Drip Irrigation System

A drip irrigation system allows you to control water usage while going light on labor. You can buy a ready-made one online or from most garden centers. The system is easy to install, and if you pick one with a timer, it will also ensure that your straw bales are watered regularly and evenly.

Make Your Own Soaker Hose

• Step 1: Using a small drill bit, prick holes in a length of garden hose. It’s easiest to lay the hose flat on the ground before starting. Go for one hole per inch of hose.
• Step 2: Avoid pricking the holes in a straight line, because the water won’t run out sufficiently if the hose gets twisted. Instead, rotate the hose as you make the holes.
• Step 3: Fix one end of the hose to your faucet and lay the remaining hose across the bales.
• Step 4: Block off the far end of the hose using a sprayer head. This can remain switched off as you need the water to seep through the holes in the hose but can be used for overflow if the water pressure is high.

DIY Drip-Feed System for Smaller Gardens

Straw bale gardening does use a lot of water, so if you’re looking for an environmentally friendly DIY project or planning a small balcony garden, consider capturing natural rain water in barrels to use before employing your faucet’s help.

Then, take it a step further and turn your garden into a recycling system by skipping the drip-feed hose and using unwanted plastic jugs instead. Here’s how:

• Step 1: Remove the lining from the plastic cap.
• Step 2: Pierce the cap itself using a small drill bit from a power drill.
• Step 3: Fill the bottle with water, replace the cap and push the bottle cap-first down into the bale.

This will enable you to save on water as well as watering time.

It’s Time to Condition the Bales

Now that you know how to create a straw bale garden to accommodate your plants’ needs and suit your gardening style, let’s take a look at how to condition and fertilize a straw bale for planting.