Horse manure makes an extremely good soil improver for the garden. Often combined with stable bedding and allowed to rot down for a couple of years, horse manure is perfect for digging into planting holes or spreading onto the surface of bare soil. Fresh manure mustn’t be used directly on the garden as it can actually remove nutrients from the soil and scorch plants, but it can be added to compost heaps.
What is horse manure?
Horse manure is the waste (excrement) that comes from horses. It’s often mixed with stable bedding. In stables, the floors are covered with a layer of organic material to absorb the waste that horses produce. Bedding material varies and may be straw, elephant grass (Miscanthus), wood shavings, pulp or pellets. If sourcing manure direct from a local supplier, find out the type of bedding material used, as this affects how long the manure should be left to rot down before using.
Why is horse manure good for the garden?
Horse manure is good for gardens because it contains nutrients that help to feed ornamental plants, fruit and vegetable crops. Rotted or composted manure combined with horse bedding is high in organic matter, which acts like a sponge in the soil, holding on to nutrients and water for plants to use, and improving the structure of all types of soil. Horse manure is often regarded as more nutritious than garden compost as it’s likely to contain more nutrients and organic matter, however this is a broad generalisation as compost quality varies, depending on the type of waste material and composting method used.
How to use horse manure in the garden
When using horse manure, ensure it’s well rotted or composted, and at least six months old. If the horse bedding is wood-based, manure should be a year old to ensure the wood has broken down completely, otherwise it takes nitrogen (a major nutrient required by plants) from the soil. Bagged manure from manufacturers is guaranteed to be well rotted.
The easiest way to apply horse manure is by spreading it onto the surface of bare soil in autumn, a technique described as ‘mulching’. Autumn is the best time of year to mulch with manure, so worms and other soil organisms have times to take it into the soil before the next growing season starts.
Early spring is also a suitable time to spread manure on soil, particularly around established plants in borders. Using a fork, spread a 5-8cm thick layer over the soil, breaking down any large lumps as you go. Keep manure away from plant stems as this may cause rot. When spreading manure around low-growing plants or clumps of perennials that have been cut back, you can cover the plants with buckets or trugs to keeps them free from manure.
Using fresh horse manure
Fresh manure isn’t suitable to use directly on plants as it would scorch roots and the bedding material wouldn’t have broken down. Only add fresh manure to soil that won’t be used for growing for at least six to 12 months, depending on bedding type. However, fresh manure does make a good compost activator, helping to speed up the rotting process and improve compost quality.
Potential problems of using horse manure
Manure direct from stables may have several disadvantages. Even well-rotted manure is likely to contain weed seeds, both from hay that the horses have eaten, and those that have blown onto manure heaped outside. The same goes for roots of perennial weeds that quickly grow in a manure heap – this means you could be importing problems into your garden.
Weedkiller contamination is another potential danger to be aware of. Ask if the pasture fields have been treated with hormone-type weedkiller used to combat broad-leaved weeds, as the chemical remains on undigested material eaten by horses. It may persist for years and, if contaminated manure is added to your soil, can lead to damaged and distorted plants.
Horse manure may contain bacteria harmful to human health so it’s a good idea to observe basic hygiene precautions when handling.
- Wear gloves, sturdy outdoor footwear, and old clothes or a boiler suit, that can be left outdoors after use
- Wear a face mask if handling dry material
- Do not eat, drink or smoke whilst handling manure
- Wash hands thoroughly after handling manure, even when wearing gloves
Which plants benefit most from horse manure?
While most plants benefit from an improved soil, there are some types often described as ‘hungry’ or which need a rich moisture-retentive soil, so give them priority. These include most fruit plants, roses, dahlias, beans and peas.
Marrows, courgettes, pumpkins and squash are closely related plants that absolutely thrive on a lot of manure. To get a massive crop, plant them directly on top of a manure heap, first making a hole large enough to fill with a bucketful of garden soil to plant into, as the plant may rot if in immediate contact with manure.
Which plants don’t like manure?
Manure is likely to be too rich for drought-tolerant plants and plants that need a free-draining soil, as well as those that require a low-nutrient soil, such as wildflowers.
Root vegetables, particularly carrots and parsnips, shouldn’t be grown on freshly manured soil as the roots are likely to fork. Soil that has been manured at least a year previously is fine and best for all root crops.
Advice on buying horse manure
- Bagged manure is available to buy from garden centres, nurseries and online suppliers. Being bulky and heavy does increase the cost of buying online, so consider how much you need and buy enough for a few months in one delivery
- Most bagged manures are described as ‘farmyard manure’ though may well contain horse manure. Although more expensive than buying loose manure locally, bagged manure has been composted in bulk at high temperatures, so weed seeds and other pathogens are much more likely to have been destroyed
- Local stables or horse owners are often keen to get rid of manure but shifting it may not be easy unless you are prepared to go and collect it, which would mean bagging it up or having a trailer. Sometimes manure is available bagged and ready for sale. If you have a large garden and space to handle it, paying for a large trailer-load to be delivered is worth investigating