Preparing a
Vegetable Plot
Growing your own vegetables is enjoying
a resurgence in popularity. During World War II the countries of the UK were told to "dig
for victory" so that every patch of suitable ground was used to produce the crops
to feed the nations of the British Isles. This reduced the quantities which up until then were
imported and reduced the burden on the embattled shipping industry.
Not only is
allotment gardening a great and rewarding pastime and a perfect stress
relieving hobby, the crops are fresh, taste better and the vitamins and
other benefits they contain, such as antioxidants, are more potent. Some of
the crops come under the description of so-called Super-foods which contain
higher proportions of these beneficial compounds.
With the current concerns about energy
usage, any reduction in the journeys taken by our food will reduce the
effect we have on the environment. It has been estimated that all of the
ingredients which make up the average family Christmas, clock up about
48,000 miles (that's twice the circumference of the Earth). These 'food
miles' all contribute to our carbon footprint, so as well as cutting down on
the energy we use directly, growing some vegetables in the garden is another
way of doing your bit to combat global warming. Even when buying organic
produce the food miles are a consideration, many of them travel great
distances before they reach the shops. Some are imported from the other side
of the world, while the locally grown crops are cultivated with machinery
then go to be packaged and to a central dispatch depot before they are
distributed to the supermarket.
The cut flower market clocks up even
greater mileage so if you like to have a display indoors, set aside a small
area to grow some flowers for cutting. This could be an area being left
fallow as part of a crop rotation cycle.
Allotments have been around since the
eighteenth century and are supported by Acts of Parliament which control the
size and the rent which should be paid, eg. the rent for a 10 rod plot was
about £20 per year in the late 1990's. There is a renewed interest in
allotments and it is more likely to be younger people from the 'professional
classes' who are signing up for growing their own, rather than the
traditional image of the flat-capped, retired labourer of old. Most
sites have waiting lists.
One council allotment officer estimates
that it requires 16 to 20 hours per week to keep the average plot in good
order during the peak growing season. He also suggested that to show some
sense of competence, applicants should not arrive at his offices wearing
stilettos if they want to have any chance of obtaining a plot! So if not
familiar with some hard work or would not be able to commit that amount of
time to a vegetable plot, it may not be the route to take - or consider
sharing with a friend or two. Visit any allotment site and there are
numerous plots which have been abandoned, much to the annoyance of the other
tenants who have to suffer the weeds and pests they harbour.
If growing vegetables for the first
time, you can try a few among the flowers, clear a small patch or two and
sow some lettuce, beetroot or spring onions - or try using large containers.
A Potager can be a neat way to add vegetables to the ornamental garden. A
series of beds are laid out in a formal pattern with stones or low hedges
around their edges and the vegetables can be planted within these boundaries
to some sort of design. Colourful varieties of many vegetables are
available, eg. bright red or yellow chard and peas with purple pods.
Most people try to grow their
vegetables by organic methods or at least with the minimum of chemical
interference - maybe the odd slug pellet or some artificial fertilizers. You
may wish to be even more adventurous and follow the Biodynamic methods or
create a Perma-culture Garden which is in harmony with the environment.
When preparing a vegetable plot it can
be very daunting - faced with a blank piece of ground usually infested with
weeds. Although some of these weeds are edible as well and can be harvested
to supplement your more cultured crops. Often an allotment will have been
neglected for a few years as the previous tenant may not have been able to
tend it, but hung on to it in the hope that they might return. A good way to
tackle the work is to divide it into four areas for rotating annual crops
plus one for more permanent planting such as rhubarb, herbs and soft fruit.
Crop rotation is important to reduce the build-up of pests and diseases,
also crops use up the nutrients differently so they can be depleted if the
same one is planted repeatedly in the same place. (Go
to crop rotation diagram)
Make a path through the centre, wide
enough to accommodate a wheel barrow and edged with gravel boards. If the
site is fairly level landscape fabric can be used to keep it from being
muddy in wet weather, but on a sloping site it would be better to cover this
with bark chips or gravel to stop it being slippery. Pea gravel will
gravitate to the bottom of the slope. Broken quarry stone and dust known as
'blinding' binds well (sometimes called GAP 20 - General All Passing - ie.
contains stones from 20mm to dust); if it is difficult to obtain, mixing
sand with gravel will bind it together. Then use more landscape fabric to
make side paths running at right-angles to the main one, pinned down with
wire hoops or plastic pegs. These can be moved to work with different
planting configurations and to make cultivation easier.
The paths will also reduce the amount
or trampling on the beds, so they may not need to be dug over again, apart
from some light forking to turn in some manure. This forms the basis of the
no-dig method of gardening where the organic matter is scattered over the
surface and becomes incorporated during planting and by the worms.
One of the problems with developing a
plot from weedy conditions or from pasture land is that there may be more
pests such as Leatherjackets and Wireworms. These pests live on the roots of
plants so when the weeds are removed they will turn on your crops. When
cultivating the soil destroy any that are found, birds will help and Robins
in particular tend to keep vigil as you work. Also there will be a reservoir
of weed seeds which will take quite a few years to be depleted. Some can
remain viable for over 20 years, but their numbers will be declining if they
are not allowed to mature.
It is probably best to be planting in
rows which run in a North-South direction, which gives maximum light and
fewer shadows. Also if including a shed or greenhouse, these should be
placed at the northern end to avoid shading any of the plot. If there are
trees, large shrubs or a hedge nearby, their roots may extend into the plot.
This will mean a loss of moisture and nutrients and the crops will suffer.
Smaller roots which reach beyond the canopy can be severed to lessen the
problem, but larger supporting roots cannot, so if possible choose another
site. Once they have been removed a vertical barrier should prevent them
from encroaching again.
Typical Plot Layout of four areas for rotating annual crops
The diagram above shows a suggested
layout for the first year. This will entail the addition of well-rotted
manure or compost in area 1, as the potatoes require plenty of moisture and
nutrition (Courgettes and sweetcorn are also gross feeders, so can be grown
in this area as well). If the whole plot is large this could be the only
area tackled in the first year, with a little work done on the rest. Cover
any undeveloped areas with landscape fabric or old carpet laid upside-down
to block out light which will kill the existing weeds and prevent others
from germinating. This makes it easier to cultivate later. In subsequent
years the rest of the plot gets the double digging as the crops rotate,
until after the fourth year you are back at area one again, but this time
the organic matter can be spread on the surface and incorporated with a
digging fork. On a smaller plot the whole lot can be dug over at once before
dividing into the different crop areas, incorporating organic matter in the
relevant areas.
| |
Area 1 |
Area 2 |
Area 3 |
Area 4 |
|
year 1 |
POTATOES |
OTHER |
BRASSICAS
|
ROOTS |
|
year 2 |
ROOTS |
POTATOES |
OTHER |
BRASSICAS
|
|
year 3 |
BRASSICAS
|
ROOTS |
POTATOES |
OTHER |
|
year 4 |
OTHER |
BRASSICAS
|
ROOTS |
POTATOES |
There are also other variations of crop
rotation systems. You don't have to slavishly stick with the above 4 area
system. Another equally practical system is shown below using three crop
areas, but again rotated annually. The important thing is that you divide
your plants into their relative "family" groups and then cultivate them in
their allocated planting area.
A simpler rotation can be followed on a
three year cycle by including the potatoes with the root crops or leaving
them out entirely if space does not allow. The choice of crops is for the
individual.
Digging
Remove all of the weeds, skimming them off with the spade if they are dense.
Then dig over the area with a fork removing the remaining weed roots and
large stones. To add the manure remove a trench of soil to one spade's depth
at one end and move it to just beyond the far end. Dig the manure into the
bottom of this trench, being careful not to bring the subsoil into the top
layer, then turn the next row of spits on top of this. Repeat this along the
area incorporating more manure and covering it with the turned over soil
until the end when the soil from the first trench is used to fill the last.
This is a process known as double-digging or as the gardeners of old called
it 'bastard trenching' - for obvious reasons. If the ground has been
cultivated before or is easily worked the double-digging can be performed
during the clearing operations.
This may seem a lot of work but the
resulting bed will give years of excellent production. If you are not
accustomed to this kind of work, then it should be tackled in small segments
over a number of weeks when the weather is suitable. The rest of the plot
can be treated the same way later on or the following year, depending on its
size and the energy of the gardener.
The following year use area 2 for the
potatoes with the addition of the manure. In the second year area 1 is used
for the rest of the root vegetables such as carrots, parsnips, beetroot and
turnips which do better in ground that has not been recently manured.
The potatoes move to areas 3 and 4 in
subsequent years then start again in area 1. This time the area does not
require double-digging as the manure can be dug into the bottom of the
trench made to plant the 'seed' potatoes. Thus the four year cycle begins
again and moves around in the same manner. The crops to be planted in the
rotation are as follows. This is the ideal cropping arrangement, but
preparation of the plot may mean it is not established for a few years.
The permanent planting areas can be
placed at the northern end to reduce shading of the plot. The choice of
crops depends on taste and size of the area available but are the ones which
remain for a number of years, eg. strawberries for about 3 and asparagus for
up to 20 years. Preparation is the same as the rest of the plot. In
subsequent years the area should be mulched with the manure to keep down
weeds and the worms will work it into the soil. The non-cultivation or
no-dig method of crop growing uses this technique over the whole plot. The
soil is not dug, instead a thick mulch of compost or rotted manure covers
the soil and the crops are planted through it. The initial preparation to
clear the site is the same, as no amount of mulching will stop perennial
weeds such as Couchgrass.
If there are periods when an area is
not in production, e.g. after harvesting a crop, it should be covered with a
thick mulch of compost or with landscape fabric to prevent weeds from
germinating. The compost will be taken into the soil by worms, so saving the
need to dig it in the following spring. Another use for fallow areas is to
grow a green manure. This is an annual crop such as mustard (spring or
summer sowing) or alfalfa (late summer or autumn sowing). It will prevent
soil erosion, smother weeds and improve the soil structure. Before the
plants mature and still have plenty of sap, they are cut, left to wilt and
turned into the soil at least two to three weeks before re-planting - roots
and all, so that they are completely buried and will break down, returning
nutrients to the soil. The soil structure is maintained better when it is
being used, a plot left barren with nothing growing (even weeds) will become
compacted and stagnant, growing roots keep it open.
Other green manures which can be grown
in the winter are Corn Salad, Claytonia (Lamb's Lettuce) or Field Beans
which do not have deep roots and are easily incorporated. Keep within the
crop rotation principles by using varieties close to the harvested crop, eg.
Field Beans after the peas/beans or Mustard after brassicas. Phacelia (Phacelia
tanacetifoliais) is not related to any vegetable so can be used after
any crop. Some of the seed which is sold for the purpose is used by
commercial growers who use heavy machinery to incorporate the deeper roots
and are not so suitable for use in the garden.
If the soil is not of a chalky nature
it will tend to become acid as the Calcium is leached out. Also the addition
of compost and manure tends to lower the pH. It may require the addition of
lime from time to time as most vegetables grow best when the soil pH is
between 5.5 and 7. Outside this range some of the nutrients can be
unavailable to plants. It is preferable to do a pH test using soil from
several areas of the plot to work out the amount of lime to add to achieve
this optimum level.
|
pH of soil |
Sandy Soil
Grams/sq m |
Loamy Soil
Grams/sq m |
Clay Soil
Grams/sq m |
|
4.5 |
190 |
285 |
400 |
|
5.0 |
155 |
235 |
330 |
|
5.5 |
130 |
190 |
260 |
|
6.0 |
118 |
155 |
215 |
The above table gives
the amount of lime in grams, to be added per square metre of different soil
types to achieve a pH of about 6.5.
Use ordinary lime (Calcium Carbonate) as it is less
caustic than quicklime (Calcium Oxide). Choose a calm day marking out the
area in one metre strips and sprinkle the lime evenly before digging it in.
This is best done well before planting to avoid scorching of roots and
should it not be applied at the same time as fertilizer or manure to avoid
the loss of Nitrogen - a chemical reaction causes Ammonia to form which is
gaseous and escapes to the atmosphere. Late autumn or winter is
traditionally the time when liming is carried out.
