Mulching, according to the WordReference Random House Learner’s Dictionary, is a covering, as of straw, spread on the ground around plants to prevent loss of water or soil. Today, this term includes covering the soil around the crops with organic and mineral materials which will favour its development.
In this article, we are going to see how mulching can protect and feed the plants.
We will explain in details the benefits of mulching and with which materials we can do so. We will answer to the following question: can we mulch all the crops? Finally, we will see at which moment during the year we can mulch.
The benefits of mulching are numerous; we are going to list them here:
- Less watering: mulching reduces evaporation and maintains humidity in the soil. Water being a precious and more and more expensive commodity (except if you have a water source at your house), better as well save it. If you mulch fruit and vegetables in direct contact with the soil, they will be cleaner. So you will also save water in the kitchen.
- Less weeding: by covering the soil around your crops with more or less thick layers (we will see that below), you forbid the light from reaching the ground and thus, weeds (which can be very interesting as a natural treatment or in our plates as you can see for example through our recipes around the nettle: as a manure or as a soup!) It is important to take off hard-to-control perennials before, such as quackgrass and bindweed.
- Less hoeing: with rain, soil gets packed. It becomes denser which troubles gaseous and aqueous exchanges. It prevents water from penetrating and roots from growing.
- Protect the plants: cover the ground around plants will attenuate the vagaries of climate: excessive warming or cooling (intense heat and frost). It will reduce plants stress and enable their growth. At the end of the season, mulching will enable to gain a few days of maturation while limiting cold effects.
- Protect and even enrich the soil: mulching protects against flows and erosion. According to the type of mulch you use, you can even enrich the soil! Life is hidden under: insects, mushrooms, bacteries. They will all eat the materials and transform them into nutritive elements which will feed your plants.
I also have to underline the drawbacks of mulching:
- A soil covered with mulch wams up less quickly than a naked soil at the end of winter. The seeds which need a certain temperature to sprout will be a bit late at the beginning. It is also true for weed seeds.
- Mulching can choke out young plants especially if the collar between the stalk and the roots is too tight. It is important to clear the collar. Be careful if you mulch with materials that are too packed, they might ferment and give diseases to plants.
- Slugs and voles like to shelter under mulch. It is better not to mulch if there are voles because there is nothing you can do against them. If you have slugs, mulch a bit later when the plants have grown a little and their leaves won’t be soft enough to their taste.
- If you don’t know where the mulch comes from – I think about straw for example – there might be chemical products in it, so be careful.
What are the different types of mulch?
Dry vegetal mulches
- straw: the first mulch to come to mind is straw. It is what is left of cereals after harvesting the seeds. It is light and lets water and air go through. The mulch layer should be between 5 and 10 cm. Straw won’t bring many nutritive elements but will last quite long. It is very good for fruit and vegetables which are in direct contact with the ground: cucumbers, squash, strawberries, melon…
- dead leaves: except walnut leaves which are toxic.
- hemp or flax mulch: they are sold in stores, are light, covering and do not contain weed seeds. They retain water, they are very good for fruit and vegetables . Flax mulching is perfect with small plants and it seems that it pushes slugs away. Have you ever noticed that?
- pine needles: use them sparingly because they are very acid. They can be used to mulch red berries, hydrangea or rhododendron.
- small shredded branches: also called Ramial Chipped Wood (RCW), it is a type of woodchips made only from small to medium-sized branches (with a diameter up to 7 cm). This shred lets water and air go through. Be careful, do not store it to avoid fermentation. It can be incorporated in the soil at the end of the season. Its main asset is its availability if you have shrubs.
Humid vegetal mulches
- hay, tweeds or vegetables greens and tops (if you don’t use hem in a soup): all there are rich in nitrogen which is very interesting. However, they are not dry and will prevent water front running through and rot if the layer is too thick. Spread them on a 1 cm layer. It costs nothing and can contain weed seeds. It will have to be renewed several times during the season. Contrary to straw, this mulch is good for fruit and vegetables which are NOT in contact with the ground.
- big leaves: think about using burdock or rhubarb leaves, they are thick and large and cover the soil quickly.
- grass-cuttings: same benefits and drawbacks as hay and other green herbs. Let the grass dry before putting it at the bottom of your plants to avoid fermentation.
Mineral mulches and others
- stones: for example pozzolan (volcanic stone) for rock plants, fully appreciated by hydrangeas. Tiles and clay balls can also be used. These types of mulch last but do not bring any nutrients. They are for ornamental plants which like warm.
- jute cloth, mulching flet and plastic sheeting: perfect to avoid weeds. They have to be put before the plants, contrary to other mulches.
- cardboard: wedged with stones on the ground to maintain it, it will be a good cover. Use unprinted cardboards and straight lines to avoid cuttings !
What can we mulch?
We can mulch nearly everything, except:
- garlic, onion, shallot because their bulb may rot.
- young plants: salad because if slugs come hiding in the mulch, they will also devour the leaves.
- it is also true for vegetables that we seed such as carrotts, beetroots, turnips, radishes. Wait for them to grow to avoid slugs eating them
According to the amount of mulch you have, give it in priority to high water-demanding vegetables such as coliflowers, cucumbers, courgettes, melons, salads and tomatoes.
When to mulch?
At the start of the season:
- wait for the ground to heat up
- wait for the plants to grow for them to be less attractive to slugs!
At the end of the season:
- you can incorporate the rests of the mulch, especially if it is vegetal and green
- you can also spread dead leaves out (see above)
- to protect the soils from winter’s bad weather and enrich the soil after harvesting, have you ever tried green fertilizers?
I hope you liked this article and that it will invite you to start mulching. We advise you to favour mulching with your own materials, untreated if possible. Mulching weakens weeds which compete with your plants and save you water and sweat to weed!
Get ready, get set and go mulching!