What is Straw Bale Gardening?

Straw bale gardening could easily be seen as a quirky, attention grabbing growing method. One that was thought up by gardening writers to give them something different to write about. Or TV garden show presenters a topic to discuss as an amusing aside to liven up the compost making.
But it is not a growing method to be considered as a serious contender alongside raised bed kitchen gardens and crop rotation.
Or is it?

In this article we’ll aim to answer the question What is Straw bale Gardening? By looking at how it works and where you could use it. I’ll give you a more practical How to grow vegetables with straw bales in another blog. Keeping them separately makes it easier for you to find what you want – the method or some answers and explanations.

Straw bale Gardening? Or Hay bale Gardening?

Does it make a difference whether you use hay bales or straw bales? And what is the difference between hay and straw anyway?
If you’ve been around horses, a farm or smallholding, you probably know this answer. But for those who are not sure, it’s an important distinction if you’re looking for bales to use in the garden.

Hay

Hay is dried grass or legume stalks, and has seeds and leaves attached to the stems. The whole plant is harvested (excluding the roots) and dried before use. Hay bales may include grasses such as Timothy and rye ; plus legumes such as alfalfa and clover.
Although dried, it may retain some moisture and tends to stay green in colour. High in nutritional content, including nitrogen, hay is used as feed for animals as diverse as horses and guinea pigs.

Straw

Straw is the dried stalks of grain crops such as wheat, barley, oats. In other words, the bits of the plant left after the grain (seeds) and chaff have been removed. It has little nutritional value and is used for animal bedding rather than food. Straw is also used for thatching roofs, although reeds make a longer lasting thatch.
However, the insulatory properties that make straw good for bedding, mean it’s useful in the garden too. For example –

as a winter mulch around newly planted shrubs
in the compost bin to improve the carbon ratio
to protect strawberries from mud splashes

What Type of Straw Bales?

It may be self-evident, but you need what are often called square straw bales although they’re rectangular in shape. Even the small round ones are too big and heavy for domestic handling. Besides, square or rectangular bales fit more easily and efficiently into gardens.

How heavy are the bales?

This is the dry weight, once you start watering them they get heavier. Straw weighs less than hay to begin with.

Square straw bales – small ones, called 2 string, or conventional, are rectangular, about 100 x 40 x 30 cm, weighing about 45 lbs / 20 kg. These are the best for most gardening situations. A 3 string bale is about 120 x 50 x 40 cm, and is about double the weight ( also depends on the density of the bale and the type of straw)

Square 4 string and 6 sting are also available; these are comparable to the small round for weight.

Round straw bales – small ones are about 4 foot / 1.2 m, in diameter and weigh 400-600 lbs / 180–270 kg. Too big and heavy!

Tip
Once the bales are conditioned, ie ready for planting they’ll be heavier. If you’re not able to lift the bales you’ll need someone to help you get them into place BEFORE you start the conditioning.

Is organic gardening important to you?

If you’re gardening organically, you may want to check that the straw has been grown organically, or at least without synthetic pesticides. (Not all farms that grow organically may be certified organic)

How long will a Straw bale garden last?

You may have a straw bale garden for as many years as you like. What you won’t have is the actual same bales of straw!

On its own, straw will take about a year to decompose because it consists of 90% carbon. But you’ll be adding water and making holes in it, which will encourage rotting. This means that for many gardeners, the bale will last one growing season only. But you could get two or even possibly three years’ use from the bales. It depends on the straw, where you place the bales, the crops you grow and the weather.

And of course, once the bales collapse, or you break them up to get at the crops, the straw itself can be used for other purposes around the garden. Sometimes its only in a condition to use as mulch or added to the compost bin.

Therefore you will need to plan to replace the straw bales every 1 to 2 years. This includes sourcing and purchasing new ones, setting them up and conditioning them ready for use. Plus you’ll need to have ways of using or composting the straw from the old bales.

Tip
Hay decomposes more quickly of its high nitrogen and water content. It should last a year, but may not. Difficult to be precise unless you know what grasses are making up the bales; the finer ones tend to decompose more quickly.

What is Straw bale Gardening – a No-Dig Growing Method?

The simple answer is: Yes.

No-dig growing methods would include –

Lasagna gardening, aka layer gardening
Raised beds – with or without frames
No-dig in ground level borders

Straw bales effectively offer a type of raised bed garden, however, like any growing method there is some preparation involved. Once they’re in place, the preparation, or conditioning, of the bales takes about 2 weeks.
In fact, you could start with straw bale and turn it into lasagna at the end of the growing season – more on this in the ‘How to’ blog.

Straw bale Gardening – benefits

Because it is effectively a temporary garden, it is useful for those who are renting a property, or know they will be changing the garden around.
Start-up costs are relatively cheap, as bales can be as little as £4 each.
The bales can be stood on virtually any surface – concrete, grass, soil, decking.
It is one method for beginner gardeners to try without much initial outlay other than time spent in the preparation.
You can have just one bale, or as many as you like, perhaps set up potager style, so it suits different sizes of vegetable garden.
Straw bale gardens work with different growing methods, for example, square foot gardening and crop rotation.
If you have a bad back, gardening with straw bales reduces bending.
Bales are about 18” high and can be raised, making them more accessible for wheelchair gardeners.
Weeding is reduced.
Garden pests such as rabbits, snails and slugs are less of a problem.
You can grow many types of annual crops and flowers in straw bales.
They are a sustainable, recyclable product, which can generally be bought locally and used in your own garden when they fall apart.

Straw bale Gardening – disadvantages

Because the bales only last 1 – 2 years, you have to constantly buy more.
You will need somewhere to dispose of the used bales, whether that’s a compost heap, as soil mulch or given to a friend with a larger garden.
Even dry, the bales may be too heavy for you to move around on your own.
You need to have easy access to water, both for preparing the bales and maintaining the crops. If situated in a sunny spot, the bales may need daily watering.
Too much standing water can cause the bales to rot, so consider this when deciding where to place them.
As the bales get older, they decompose, which looks straggly and untidy. It can also make them unstable if you’re growing taller crops such as tomatoes.
You will probably still get weeds – from the soil below, from seeds that were in the bale itself and from airborne seeds.
If the straw comes from a field that was sprayed in the last few years with a persistent herbicide, this could leach in to the plants which are growing in the bale and potentially into the surrounding soil.
Bales placed on wood – decking for example – will make it damp and could cause the timber to rot.
Garden pests such as rabbits are likely to still be a problem, just as they would be in an ‘ordinary’ raised bed.
You will still need soil or compost for the majority of the plants you’re growing, even if its only a small amount. This may be for stability reasons, water retention or nutrition.
As in any container garden, the plants will be dependant on you the gardener to fertilise them.

and finally

Hopefully I’ve answered the question “what is straw bale gardening?” in this article. There will be a more practical How to grow vegetables with straw bales blog. I also intend to experiment a bit more with straw bales myself and with some of the Plews Gardening Course students who are interested.

For further gardening advice and inspiration, check out Plews Potting Shed blogs, including the selection below and our monthly Tipsheet – You could come and find us on Instagram Pinterest and Facebook too.