No more weeding! And with a good mulch, you also save on watering. But above all, thanks to mulching, your flowers are in perfect health, and you get better fruit and vegetable harvests. There are many materials to mulch: plant mulches, mineral mulches, or even mulching cloths and felts. In this article, we explain everything you need to know about mulching. You will discover what mulching is for and which one to choose for your garden or vegetable garden.
What is mulching?
In nature, when the ground is bare, it is not normal! So it is to avoid leaving the soil bare that gardeners use the technique of mulching. Mulching covers the earth with plant, mineral, or synthetic materials to nourish and protect it. Different types of mulch can be applied anywhere in your garden. Including potted plants, fruit trees in the orchard, and vegetables in the garden.
The advantages of mulching for your garden
When correctly done, mulching will bring you a whole series of advantages that will improve your crops’ development and facilitate the management of your vegetable garden.
•Less watering: bare soil facilitates water evaporation and plant transpiration. Natural mulch helps limit these phenomena and acts as a sponge for better water absorption in rainy weather. It also acts as a thick cover that keeps the soil cool and prevents drying out in summer.
•Avoid the phenomenon of capping: clay and loam soils tend to compact and form a crust on their surface after rain. Mulching your soil with plant mulch, for example, helps avoid this phenomenon.
•Less weeding: protecting your soil from light with a mulch will prevent the proliferation of “weeds.”
•A more fertile soil: during its decomposition, your mulch will turn into humus and enrich your soil with nutrients essential to plant growth.
•Less soiled crops: your crawling crops (strawberries, cucumbers, melons) will no longer be in direct contact with the soil but with your mulch.
•Promotes life in the soil: mulch provides a protective layer that reduces temperature and humidity variations. It also encourages microbial life on the surface, which allows the release of nutrients necessary for plant development (mineralization).
•Reduces the risk of disease: the physical screen of the mulch reduces the spread of diseases transmitted by the bursting of water drops when they reach the ground. This is particularly the case for mildew spores that are projected in this way on leaves and stems close to the ground.
How to choose your mulch?
There are two main categories of mulch: mineral mulch and organic mulch. They include several varieties, and you will have to find the one that will best suit your soil or the type of crop you want to grow.
It is not biodegradable, and its use is recommended for plants that can adapt to hot and dry climates.
There are several varieties of mineral mulch, such as crushed slate, gravel, or flat stones. The most used is pozzolan: it is a volcanic rock rich in silica whose honeycomb structure is an excellent thermal insulator.
Beyond its function of protecting the soil, this type of mulch has to fertilize properties when it decomposes and turns into humus. Therefore, it can be divided into two categories according to its decomposition speed.
Long-lasting mulches > 4 years
These should be used on perennial crops that require little renewal, such as trees, shrubs, and perennial beds. You should therefore exclude them if you are looking for mulch for vegetable gardens.
•Wood chips: These provide long-lasting protection, and you should apply a nitrogen-rich fertilizer before spreading them.
•Pine bark: recommended for acid-loving plants.
•Pre-composted shredded hedge clippings from trees and shrubs: If you have a shredder, you can turn your clippings into mulch. However, remember to exclude coniferous pruning waste to avoid acidifying your soil.
Mulch with an average lifespan < 4 years
They can be used for all types of plants and short-cycle crops.
•Grass clippings: You can recycle your grass clippings into mulch. But remember to limit its thickness to a few centimeters to avoid rotting.
•Unripe compost: Use only on plants that have already developed. Avoid contact with stems and trunks to avoid burns.
•Flax chaff and hemp chaff: these mulches, with their excellent thermal insulation properties, are very well suited to mulching vegetable gardens and beds of annuals or perennials. In addition, their almost neutral or slightly acidic pH makes them ideal mulches for your rose bushes.
•Dead leaves: their excellent C/N ratio allows them to be naturally composted at the foot of the plants.
•Buckwheat hulls: this versatile mulch has strong opacifying power and has a repulsive effect on slugs and snails.
•Mulching felt made of plant fibers can be used to create a perennial bed or a hedge. It lets water and oxygen through, but not light. This particularity allows it to be used on soil already invaded by “weeds” and transformed into humus after a few months.
•Cereal straw: this is the so-called “traditional” mulch. But it isn’t easy to find untreated organic straw today. Moreover, straw tends to fly away and can bring seeds of plants that you do not necessarily want to see growing in your garden (weeds).
Here are some examples of how long organic mulches last:
•Two to three years > flax chaff, sunflower hulls, buckwheat hulls, and hemp chaff.
•About a year > depending on their size: straw leaves.
•A few weeks > grass clippings.
There is a third category of mulch, the mulching cloths felt and films woven plant cloths, plastic films, and even newspaper and recycled cardboard!
This mulch is beginning to be commonly used because they are affordable. Also, they are used together with the other two mulch.
How to make a success of mulching?
Now that you know what type of mulch is best for your crops and how long you want to protect them, you can finally start mulching your soil. Here are some tips to help you know when to mulch and how to mulch:
•Do not mulch in high winds.
•Don’t mulch on frozen soil, as you may delay its warming up.
•Do not mulch on weeded soil unless you are using plant fiber mulch felt.
Water your soil abundantly before and after mulching.
•Respect a minimum thickness of 5 to 10cm. Except for buckwheat hulls and hemp, which have a strong covering power.
•Split your mulching in two or three passes before reaching the recommended thickness to avoid smothering your young flower and vegetable plants.
•Respect the spacing when creating your perennial bed so that they cover your mulch one or two years after planting.
•Add 2 to 3 cm of mulch each year to compensate for losses when using short-lived organic mulch.
•If you want to incorporate your mulch into the soil, do so in the fall.