What is mulch?
Mulch is any material used to cover the soil around your plants. The two types of mulches are organic and inorganic. Organic mulches are natural products such as straw, bark and leaves. They break down over time, adding to the nutrients in the soil. Inorganic mulches are gravel, pebbles, plastic and anything else unnatural. They don’t break down so won’t need to be topped up but add nothing to the condition of the soil.
Which mulch is best?
The best type of mulch is fairly coarse which allows for air circulation around plants and penetration of water into the soil. Finer mulches like lawn clippings are best put into the compost heap where they can break down and applied to the soil at a later date to improve it that way.
Types of mulch
Mulches such as sugarcane, pea straw, lucerne are good for vegetable gardens, around fruit trees and flowering plants. As they break down, they release nitrogen into the soil, which is great for general plant growth. These mulches are sold in bales so are easy to transport and distribute.
Woody mulches come in a range of different colours and can be used as a design feature around the garden. Darker mulch looks great in a native garden as it imitates how these plants appear in nature. Woody mulches have the advantage of not breaking down as quickly as straw-type mulches so you don’t have to top it up as often.
Succulents and cacti naturally grow in arid areas, so inorganic mulch like rocks and pebbles really suits them. It also makes these plants stand out so the garden is even more striking.
There are a few tips to putting in mulch for the best results. Water well before applying mulch so you start with moist soil. Lay it a maximum of 5cm deep, and around 2-3cm for inorganic mulches. Keep it away from trunks of trees and stems of plants. Woody mulches remove nitrogen from the soil as they break down so occasionally fertilise to compensate.