Mulching the garden: what vegetables can be mulched in permaculture?

Soil preparation is a key point when you start growing crops in the garden, and this is particularly the case in permaculture. One of the fundamental practices for improving soil structure and encouraging plant growth is mulching. This technique involves covering the soil with a layer of organic or mineral matter to preserve moisture, limit weed growth and enrich the soil.

Spreading mulch over plants in the garden thus helps to achieve better yields with healthy, tasty vegetables. Why? Because not only does it save time on weeding and save water, it also improves soil fertility by stimulating biological activity. Mulching preserves soil moisture by limiting evaporation and inhibiting the growth of weeds. However, it is not always easy to use it everywhere in the garden and certain precautions must be taken to avoid nutrient imbalances.

What are the benefits of mulching?

The benefits of mulching are numerous:

• A considerable time saving: less need to water and very little need to weed, if at all.

• A soil enrichment: as it decomposes, mulch nourishes the soil with organic matter and encourages underground biodiversity (earthworms, micro-organisms).

• Thermal regulation: mulch protects roots from the cold in winter and keeps the soil cool in summer, preventing water stress and frost.

• Recycling plant waste: grass cuttings, dead leaves, wood shavings... Everything can be reused in the garden.

By improving the quality of the soil in the vegetable garden, mulching also increases the production and quality of vegetables. It provides minerals and reduces the need for chemical fertilisers, making it an ideal solution in permaculture.

For effective mulching, we use a variety of materials: grass, shredded plants, dead leaves, partially decomposed compost, or even ramial fragmented wood (BRF). The thickness of the mulch should also be adapted according to the crop: a layer of 5 to 10 cm is generally recommended.

However, a major disadvantage of mulching is that it can attract certain pests, such as slugs, which find an ideal refuge under the organic cover. It is therefore essential to observe your garden and adapt your mulching accordingly.

What are the types of mulching?

There are a wide variety of materials that can be used to mulch crops:

Organic mulches

• Turf clippings (use in thin layers to prevent fermentation).

• Straw (rich in carbon, it decomposes slowly but can cause nitrogen starvation).

• Dead leaves (ideal for light soils and rich in micro-organisms).

• BRF (from the shredding of young branches, it improves soil structure over the long term).

• Pine bark and needles (acidify the soil, reserve for heathland plants such as bilberries).

• Hemp fibres or coconut stalks (biodegradable and rich in organic matter).

• Kitchen waste (vegetable peelings, coffee grounds, etc.).

Mineral mulch

• Gravel, pozzolan or crushed slate (stabilise the soil and retain heat, useful for Mediterranean plants).

• Nut or cocoa shells (slowly decomposable, enrich the soil with organic matter).

• Lime or wood ash (usable in small quantities to amend the soil with potash).

Each type of mulching has its advantages and disadvantages. For example, straw is very practical because it decomposes slowly, but it can cause nitrogen deficiencies. It is therefore advisable to supplement it with green waste to balance the nutrient supply.

What vegetables can be mulched in permaculture?

In permaculture, mulching is beneficial for many crops:

• Summer vegetables: tomatoes, courgettes, peppers, aubergines, cucumbers...

• Root vegetables: potatoes, parsnips, turnips, Jerusalem artichokes...

• Cabbage and leafy vegetables: lettuces, chard, spinach, chard, celery...

However, some vegetables require special attention before being mulched:

• Direct-seeded root vegetables (carrots, radishes, beetroot): wait until the young plants are well developed before applying mulch, otherwise they risk being suffocated.

• Bulbs (garlic, onion, shallot): these crops do not tolerate excessive moisture well. Mulching them too thickly can encourage them to rot. It's best to mulch them in autumn when the soil is at rest.

In conclusion, mulching is a valuable permaculture technique that facilitates the gardener's work while improving plant health and soil fertility. However, to maximise its benefits, it is important to choose the right material and adapt it to the specific needs of each crop. Good observation and a few adjustments will help you get the most out of this natural, environmentally-friendly method!