How Much Cow Manure For Vegetable Garden

The benefits of manure and how to choose the best type for your garden

The benefits of manure added to garden soil are enormous and totally worth the stench.

Jun 18, 2019 2:38am

Starting out as a gardener means facing a steep learning curve. There's so much to learn about clipping, pruning, weeding, fertilising, watering and more. At some point on the journey from black thumb to green thumb, you'll no doubt be confronted by a heap of steaming, smelly manure. But once you learn how to use it, manure is bascially gardening gold.

The benefits of manure added to garden soil, either dug in or spread over a garden bed as mulch, are enormous.

Every seasoned gardener knows that the secret to a great garden is healthy, happy soil. Soil quality depends on factors such as drainage, nutrient density, salinity levels, pH levels and more. The benefit of using manure in the garden is that, when used correctly, it will improve virtually all of these factors.

Healthy soil is the key to a healthy garden. Photo: Brent Wilson / bauersyndication.com.au

In essence, manure is just another type of fertilizer. Fertilizer Australia refer to manure as an organic fertilizer. These types of fertilizers are "derived from biological sources such as animal manures, and composted food and plant material."

There are quite a wide range of manures, from animal-derived to plant-derived, and here we cover some of the main types of manure used in Australian gardens and how best to use them.

TYPES OF MANURE

The word manure can refer to two things: animal manure and green manure. As the name suggests, animal manure refers to animal faeces. Green manure, on the other hand, is made from organic materials, such as lawn clippings, pruned plants and leaf material that is left to compost before working into the soil to add nutrients.

There are many types of animal manures, but the main three most well-known types are cow, horse and chicken.

Manure can be dug into the soil, or spread over the top of a garden bed to improve soil quality. Photo: Maree Homer / bauersyndication.com.au

WHAT IS THE DIFFERENCE BETWEEN HOT AND COLD MANURE?

Manures can also be divided into 'hot' and 'cold' categories. This is the layman's term for gauging a fertilizer's carbon-to-nitrogen ratio. Hot manures tend to be higher in nitrogen, which will burn plants if applied to the garden before an adequate composting period. Horse and chicken manure, for example, are both considered hot manures.

Cold manures contain a higher ratio of carbon to nitrogen and release nutrients in a much slower manner. Cow and sheep manure are both considered cold manures. It is still a good idea to allow manure to mature before using it in the garden, regardless of whether it is considered hot or cold.

Cow manure is a good all-rounder, as is mushroom compost (a type of green manure). Both of these manures are affordable to purchase in large quantities. They can be quite alkaline, however, so before applying to an established garden check its pH (the level of acidity or alkalinity). Use a pH test to check the product. You're aiming to achieve a pH level of about 6-7.

COW MANURE

Cow manure is extremely affordable and a great garden all-rounder. Once matured, cow manure can be used on all matter of plants, including native plants.

Because cows eat grass, their manure is perfect for adding structure and increasing aeration in the soil. Earthworms will also be happy in soil combined with cow manure.

HORSE MANURE

The first type of manure that probably comes to mind for beginner gardeners is horse manure.

Horse manure is pretty smelly, but allow it to compost and the smell will all but disappear. Once the smell has gone, it's ready to use in the garden.

Horses are usually fed supplements, which means that their manure is slightly higher in nutrients than cow manure.

All manure should be allowed to mature, or compost, before being applied to the garden. Photo: Sevak Babakhani / bauersyndication.com.au

CHICKEN MANURE

Chicken manure is fast-growing in popularity. That's because it is relatively high in nutrients when compared to horse and cow manure. Unlike cows, horses and even sheep, chickens have a much more varied diet, which makes their droppings highly valuable.

It tends to be high in nitrogen and phosphorous. Use sparingly in gardens with native plants (which generally require less fertilizer anyway) and ensure that the manure is well-composted before applying to an established garden.

Be warned, if chicken manure is not composted well, it can burn and even kill plants.

WHAT ABOUT DOG AND CAT MANURE?

As a general rule, dog and cat manure is not considered suitable for gardens. This is because the faeces produced by dogs and cats often contain harmful parasites, bacteria and viruses.

These pathogens could impact negatively on human health, particularly when used on gardens created for food consumption, including vegetable patches, fruit trees and herbs.

Droppings from household pets are not considered safe for most gardens, particularly in gardens where food is grown. Photo: Abbie Melle / bauersyndication.com.au

CAN YOU USE MANURE STRAIGHT AWAY?

There are some specific cases when you can use manure straight away (such as establishing a new garden or garden bed), but generally speaking, it is not recommended.

According to Fertilizer Australia, manure is often "composted, mixed or pelletized to improve the availability of nutrients, to control pathogens and weeds, and to change their handling characteristics."