Page 36 - Simply Vegetables Spring 2022

Mulching
Mulching is a technique that is more associated with ornamental gardening like shrub and herbaceous borders, around trees etc. than with vegetable and fruit growing. But it is a technique that can be used in both the fruit and parts of the vegetable garden and has many advantages.
Mulching is carried out to reduce or prevent weed growth, reduce water loss from the soil and if organic mulches are used will improve the fertility of the soil
as well as insulate the soil from extremes
of temperature. So, what is a mulch? Basically, it is a surface covering of the
soil with either an organic material (bark, woodchip etc.) or and inorganic material like geotextiles or woven polyethene. Looking at the organic materials first these include bark flakes and chunks, woodchip, compost, manure, grass cuttings, cocoa shells, straw, leaf mould, spent hops, spent mushroom compost, sawdust etc. I will give more details on these later in the article.
The inorganic materials include black polythene, Mypex, Weed Out, Plantex, other geotextiles and propriety mulches. These last for a good number of years
and some for at least 15 years and can be walked on without damage. They do not have the most attractive of appearance
but can be covered with pea gravel,
glass beads, slate, granite chippings bark flakes and other similar materials. The advantage of the textile mulches is they stop the covering material mixing with the soil below which means they last longer. Although they may look expensive in the garden centre, shop around and try the internet as large rolls are very competitively priced and you could share with your neighbours or friends. If they last 10 to 15 years and save you a lot of weeding and watering I think you will find them good
value for money. The inorganic mulches can be laid before the area is planted and pegged in place with wire pins, then an X is cut into the material where plants are planted, a hole dug and the plant firmed into place then the material folded back. If the ground is already planted lay the material over the area and around the plants and then cut slits so the material can be slotted around the plants and then pinned down.
The organic mulches are spread to a depth of 50 to 100mm (2 to4”) deep
depending on what you can afford or have available. Do not apply less than 40mm
as it will likely only last a year before it has disappeared. Also do not pile it around the base of plants especially trees at it can rot the bark, leave a 100mm gap around the plants. If applied to 100mm depth it will usually last for two or more years before
it needs topping up depending on the material used; woodchip last longer than compost as it decomposes slower. Bark, woodchip and sawdust need composting before using as a mulch otherwise they can “pull” nitrogen out of the soil as they decompose (the bacteria need the nitrogen as a source of food as they break down
the carbon in the woods, the nitrogen is returned to the soil later).
Grass cuttings should only be used to
a depth of 30 to 50mm deep otherwise they become a slimy and smelly mess,
also if they contain a lot of dandelion or daisy flower heads these can still produce seeds which will grow! Partly defeating
the purpose of mulching. Any manure or compost used should be well rotted or they may contain a lot of weed seeds that will also grow, but at least they are easy to pull out!
Mulches could be more widely used in the fruit and vegetable garden so have a look at how you could use them and save yourself some work. I will look at some uses first in the fruit garden where there use is more common, starting with the
36 Simply Vegetables