Benefits of summer mulching
Mulching in summer, after early crops have been harvested has many benefits. It prevents weeds and saves hours of weeding or digging in the autumn and it improves the soil for the following year.
The following photos were taken in early August 2018 on a patch that had been used for broad beans (Vicia faba) and onions (Allium cepa). These two crops had been harvested during July. A few weeds were growing, but it wasn’t too bad. 2018 was a dry hot summer and the crops had been hoed. In wetter years the weeds are much more vigorous.
Stage 1 – flatten weeds and any crop residues
It is not necessary to pull out or dig the weeds. They may need flattening a little so that cardboard can be placed on top of them more easily. If the soil needs to be enriched, add manure or well-rotted compost onto the soil now (do not dig it in, place on top of the soil but before the cardboard.
Stage 2 – assemble your materials
You will need cardboard (or possibly newspapers), and plenty of mulch. The bags shown below contain pulled-out weeds from another garden and sawdust. Other materials used in this session were tree shreddings (leaves and twigs). I often use grass cuttings, straw or whatever organic matter is available in bulk.
Stage 3 – Prepare cardboard to cover the weeds
It may be necessary to cut some of the card. I use an old saw. Whole newspapers may also be used, but difficult on a windy day! Ideally remove any sticky tape from the cardboard as this is plastic and will not rot,
Stage 4 – Place card on top of the weeds and soil. Secure with heavy objects if there is a breeze.
Best not to do this if there is a fierce gale, but even a gentle breeze may move the card. Use bags of weeds, mulch or even pallets to secure the card.
Stage 5 – Cover the soil and weeds as thoroughly as possible. Try to avoid gaps as weeds will grow through them.
Stage 6 – cover the card with a thick layer of mulch
As mentioned before – whatever is available. This time I had pulled out weeds from another garden, sawdust and tree shreddings. On other occasions I have used grass cuttings, straw, wood shavings etc. Any bulky organic matter will do, but try to avoid weeds with seeds. The seeds may germinate.
Stage 6 (continued) – make sure the mulch is thick
At least 10- 15 cm thick. The card shouldn’t be visible at all. Thicker is better. More mulch can be added in subsequent days or weeks to build up the thickness.
The pallets in the above photo is where the mulch is not yet thick enough. When more mulch is available the thickness will be increased.
Stage 7 – leave and allow the mulch to work
The card will kill the weeds, as they have no light for photosynthesis. The dead weeds, card and mulch will gradually rot and decay, becoming compost. Worms will do the work for you. In a few months time, the soil will be weed-free, crumbly, soft and ready for planting. Rain will soak through the mulch and weeds, but the surface will not get sticky. If necessary you can walk on the bed in wet weather. if any weeds do find a way to grow through the card and mulch they can be removed easily.
Here’s one I did earlier – a nearby squash plant is trailing across the mulch.