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Make a sheet mulch bed
by Patrick Whitefield from Permaculture in a Nutshell
There are many ways of using mulch in the garden. One of the most valuable ways is when starting a new garden from scratch on a site full of perennial weeds.A task that looks utterly daunting when you think of digging it becomes quite easy when you use mulch.Here is how to go about it:
Knock the weeds down flat. It is not necessary to cutor remove them. A thin scattering of a high-nitrogen manure, such as blood and bone meal or chicken manure, is helpful at this stage but not essential.
Cover the area with a layer of cardboard, newspaper or other organic sheet material.The purpose of this layer is to kill the weeds by excluding light. There must be no gaps and plenty of overlap between the pieces, say 20 cm, to prevent vigorous weeds zig-zagging up between them. Big sheets of cardboard are best because you will get fewer joins, and an old carpet is ideal as long as it is made entirely out of natural fibres because everything you use must be able to rot down. Newspaper is only thick enough if you use the whole thing, opened out; do not try to economise by using just a few sheets.
Next comes a layer to weigh the sheets down and provide some nutrients. Manure is ideal (most of ourcities are ringed by riding stables which have plenty of it to get rid of), though seaweed will do, or partly rotted compost, provided it is free of weed roots and seeds.The manure does not need to be very well rotted; three months old is sufficient. This layer should be 5 to 10 cm thick.
Now it is time to plant. Potatoes do especially well on this system. Next best are plants which are grown at wide spacings, such as marrows, sweet corn or the cabbage family. Transplants often do better than seeds,as seedlings which have only just germinated can get buried when birds come and scratch the mulch in search of grubs and insects.Take a sharp tool, such as an old screwdriver or knife, and stab it through the mulch in the ground.This makes a hole in the sheet layer for the plantâs roots to get to the soil below. Scrape away the manure from around the little hole, replace it with a couple of double handfuls of topsoil from elsewhere in the garden, and plant into this. It isnot necessary to get the roots down into the soil below the sheet mulch. They will find their own way there.Water the individual plants well, but do not water the mulch between the plants. As mulch isso efficient at conserving moisture, this is the only watering you will ever need to do, except in avery dry year.Crops with many small seeds, like carrots,are not suitable. But remember, this system is specifically for opening up new ground. You can grow carrots on this patch next year, or specially dig a piece of ground for them if you cannot wait until then.
Finally, cover the bed with a layer about 20cm thick of straw or something similar. A mix of grass clippings and fallen tree leaves works well,and most local councils have plenty of both to get rid of. Hay is risky, because it may be full of seeds which will germinate and give you a big weed problem.If you have planted potatoes you cover the whole area, but seedlings need to be left poking through. If the weather is wet, leave this layer off until the plants have grown big enough to be able to survive the attention of slugs. Collecting the mulch can take a little time, but it is as nothing compared to the task of digging up all those weeds and picking the pieces of root out of the soil one by one. As well as saving labour and cutting down on water use, sheet mulching is an excellent way of converting some of the detritus of the throw-away society into soil fertility.
Published by Permanent Publications and distributed in the United States by Chelsea Green Publishing Company. ISBN 1-85623-003-1 Used with permission of publisher.
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