When & How Mulch Your Garden (Video)

Spreading mulch is one of the best things you can do for your garden, as it adds nutrients from decayed plants back into the soil: like in nature, but better!

What is Mulch?

In the broadest sense, mulch is any substance that you spread over soil in order to keep the sun off it while still allowing rainwater through, thus preserving moisture and suppressing weeds.
It also makes pulling up weeds easier, because the weeds that do come through will tend to root in the loose mulch more than the soil, at least when they are still young.

Organic matter is the best mulch because it slowly decays and feeds the soil, but inorganic stuff like gravel works too.

In the ornamental garden, most people prefer aesthetically pleasing substances like bark chips, which come in pretty colours and last for a long time.

In the fruit and vegetable kitchen garden, well rotted mulches that release nutrients quickly are preferred, and these are typically topped up every year.
Straw is also common, being so widely available, although it won't add much to the soil nutrient-wise.

However, we cannot stress this enough: any organic matter that does not contain weed seeds or persistent herbicides makes decent mulch. 

You do not dig mulch into the soil, so it is not a growing medium: it supports the soil below it, which is where the roots of your plants are (some rugged plants will root anywhere, of course)

Yes, well-rotted material will release nutrients immediately, so it is better for hungry plants, but un-decayed stuff is fine: that is how all mulch in nature starts off! 

The big exception is fresh manure from animals that don't ruminate, like horses and chickens, which is often too high in nitrogen (known as "too hot") for your border plants (mature trees and large shrubs with deep roots should be fine).
Their manure should be well rotted before spreading around smaller plants, especially vegetables.
Cow, goat, and sheep manure is double-digested, and does not have this problem.

Woodchips make great mulch in most situations, other than your vegetable beds. There are two old chestnut myths about using woodchips,

Myth 1: Fresh woodchips rob the soil of nutrients.

Myth 2: Woodchips from conifers (like your old Christmas tree) acidify the soil. 

Both are false, and you can use fresh conifer woodchips anywhere you like!

How and When to Apply Mulch

The best time to mulch your garden is late winter / early spring, when the soil temperature is rising. But as with so many things in the garden (and life!), the most important thing is not when you mulch, but that you mulch.

The only potentially bad time to mulch is when the soil is parched dry in summer, because the mulch will prevent light rains from penetrating the soil.
During summer, always mulch after heavy rains, or a thorough watering.

You will need some organic matter like compost or our peat free magic mulch, and a garden fork or spade.

The inimitable Robert Pavlis lives in Ontario, Canada with a similar-ish climate to the UK, and is here to tell all about mulch. 

Best Mulch for Ornamental Gardens

Best Mulch for Vegetable Gardens