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Garden layout and DrainagePlot sizeThe use of beds Drainage There are many ways to lay out a vegetable plot, and what is best is very much a matter of individual taste, but plot size, the use of beds, and drainage are general issues that I'm going to discuss here. Plot sizeIt doesn't require an awful lot of training to produce a bountiful vegetable garden, but it takes work. Many vegetables do badly if left to them selves and the parts that most people would eat are usually the last to appear. It is very important to give vegetables the best possible conditions from the start and to make sure that growth can continue without interruptions.A well managed 25 sqm plot produces a minimum of 75 kg of vegetables. One hundred sqm and the same effort give less than 50, much of it stunted, damaged and ready for the compost heap. Depending on vegetable selection and the gardener's degree of fancy for neatness, each square meter needs three to eight minutes of attention every week during most of the growing season. A simple calculation tells us that 25 sqm means two hours of work every week. This is if you master the basic skills. For beginners we are talking about three to four hours. It can actually be done in less time, but not without a considerable loss of beauty and pleasure.
There is a dark and secret power forcing most gardeners to increase the size of their vegetable plots far beyond what they are willing to take care of. I haven't been able to figure out the exact mechanism of this strange phenomena, but to escape from the trap and realise that smaller can be better is the first step towards an excellent result. Many vegetable gardeners could probably increase their harvest greatly by reducing the size their plots. Not only will the harvest be bigger. It will look neat too.
The use of bedsIf you walk on the soil you will pack it down, especially if it's wet. If you plan to use heavy machinery in your garden, or want to weed your vegetable plot using a horse, you have no alternative but to drive or walk on the soil between every row. For everybody else I strongly recommend the use of beds and that walking is restricted to paths. Packed soil impedes root growth, microbial activity and makes weeding a much harder work. With beds you can move around in your garden even when the soil is soaking wet without doing any harm. My beds are 100 centimetres wide and the paths 50 cm including the sloping sides of the beds. This size makes it easy to reach the middle of the beds and there is enough room to crouch down. The combination of beds and the addition of lots of organic matter keep the soil loose and open. Beds that remain in the same place from year to year also make crop rotation very easy. It's much harder to determine were last years carrots were if your vegetable garden is simply a large flat soil surface.
My beds are raised, but they don't have to be. In dry climates it can actually be advantageous to lower the beds. In the cold and wet Swedish climate raised beds should be favoured because:
Not related to climate are these advantages:
Top DrainageA plain ditch is the simplest way to drain excess water from the garden. As long as the level of the water table is higher than the water level in the ditch water will move through the soil in the direction of the ditch. The major advantages of a ditch are that it is cheap and that you can be pretty sure that it is working. Disadvantages are that it needs maintenance, that it will be a reservoir for slugs, and that burrowing rodents will make it their home. It will also occupy a lot of surface area in your garden since a ditch should have sloping sides to prevent it from collapsing. You will also have to dispose of the excavated soil including boulders, old car batteries, mummies, and whatever you unearth.
Sometimes there is a strong horizontal flow of water in the soil. This was the case in my garden in Saltsjobaden. To the west of the plot there is a swamp where the water table is about two meters above the soil surface of my garden. Between the plot and the swamp there is a grass covered slope. In the spring this area is so waterlogged that water is running on the surface. This water used to collect where my garden is, but one of the first things I did was to install a single drainpipe between the wet slope and the plot. This pipe diverts the water to a nearby ditch. It may not always be that easy, but if you can figure out the direction of soil water flow, a single drainpipe or ditch can stop the excess water from ever reaching your garden.
vegetables@frideen.com Last major update 2004-12-10 Copyright© Anders Frideen |
The alternative to ditches is to lay down some kind of underground drainpipe. Perforated plastic pipes are cheap and easy to handle. A width of two inches is sufficient to drain a relatively small area like a vegetable plot, but wider will last longer before sedimentation clogs the system. There will be more sedimentation if the slope of the pipe is inadequate. A fall of at least 1 cm per m is enough provided that the slope is constant. If the pipe is embedded in gravel drainage will be more effective and root growth into or around the pipe will be restricted. The pipes should preferably be buried at a depth of 1m, but a pipe at 50 cm will be much better than no drainpipe at all in a wet soil. A shallow pipe is better placed under a permanent path, not in the root zone of your vegetables. At the outlet, the end of the pipe should be covered with wire mesh to prevent the entrance of rodents or other animals that might destroy the system. On heavy clay soils, where water movement is slow, the spacing between pipes should be less than 10 m. On other soils the spacing could be wider.