The secret of growing home garden
vegetables successfully is to understand their special requirements for
cold and warm areas. Many vegetable crops fail simply because they are
planted out of season.
Cool season vegetables grow best at
temperature around 10C to 20C or even lower and are usually resistant to
frost. Plant broad beans, broccoli, Brussels sprouts, cauliflower,
kohlrabi, onions, peas, spinach, turnips and Swedes in late summer,
autumn or early winter to grow during the cooler months.
Warm season vegetables like much higher
temperatures (20C to 35C) and may tolerate even hotter weather. They
will grow poorly at low temperatures and are all important warm season
vegetables are beans, capsicum, egg plant, okra, potato, sweet corn,
sweet potato, tomato and the vine crops (choko, cucumber, marrow,
squash, pumpkin). In mild and cold climates they are planted in spring
or early summer to grow during the warmer months. In tropical and
sub-tropical climates, many can be grown throughout the year.
Beetroot, cabbage, carrot, celery,
endive, leek, lettuce, parsnip, radish, rhubarb, silver beet, spring
onions and witloof (chicory) have intermediate temperature requirements.
Some root crops may 'bolt' or run to seed if sown too late in the autumn
or winter or too early in the spring. Some varieties of lettuce will run
to seed it sown in warm weather, so it is important to select
sure-heading varieties for summer sowing.
It is not necessary to have different
soils for different vegetables. A soil that yields choice tomatoes,
should also yield choice cabbages, carrots and pumpkins. The ideal soil
for vegetables should have a loose crumbly texture to aeration and
drainage, but should also be able to hold water and nutrients. Improve
sandy soils with animal manure, vermiculite or peat moss. Clay soils are
improved by adding organic matter to improve crumb texture and coarse
sand to improve texture.
The quantity of water and the frequency
of watering depends on the water-holding capacity of the soil: Clay
soils hold water well, sandy soils poorly. Watering also depends on the
depth to which the roots of different vegetables grow, the stage of
growth and the weather conditions. Never wait until vegetables start
wilting before watering, for they do not take kindly to 'on-off'
treatment. If the soil is dry just below the surface. If the soil is dry
just below the surface, then it is time to water again. Early morning or
evening is the best time for watering vegetables to avoid high
evaporation in the middle of the day.
Mulching is another way of conserving
soil moisture. The best mulches for vegetable gardens are garden
compost, leaf mould, well-rotted manure or dry grass clippings.
For most vegetables, including root
crops, dig the soil to spade depth (20-25cm) but do not bring subsoil to
the surface. You can improve drainage of heavy soils by raising the beds
15-25cm above the surrounding level and sloping the sides of the bed to
about 45 degrees.
To grow quickly, vegetables need as
much sunlight as possible, especially in winter when days are short.
Avoid shade from buildings, fences, shrubs or trees. On level sites run
the vegetables in a north-south direction. On sloping sites run the beds
across the slope.
Always plant tall vegetables such as
sweet corn or tomatoes in such as way as to prevent shading low-grouping
crops. When growing seedlings, expose them to sunlight as soon as the
emerge, otherwise they can become tall and spindly. A few vegetables are
herbs such as choko, leeks, mint, parsley and rhubarb will tolerate some
shade.
Wind damages the leaves and stems of
vegetables and weakens the root systems. Cold winds will slow growth and
hot winds evaporate water from plants and the soil surface. Protect by
planting trees shrubs or hedges or timber wind breaks. Artificial wind
breaks also provide support for climbing beans, cucumber and climbing
peas.
Growing vegetables in containers has a
special appeal for people who live in flats, home units and townhouses.
Tubs, pots and troughs offer a simple solution for providing every home
with some fresh vegetables.
Relatively inexpensive, lightweight
containers, 'easy to apply' fertilizers and the development of early
maturing, compact vegetable cultivars have helped to create this
interesting and rewarding hobby.
Salad vegetables - capsicum, carrot,
cucumber, lettuce and tomato - are popular for containers because of
their high quality and flavor when freshly picked. Dwarf, compact
cultivars of salad vegetables and others like bush squash and marrow
(zucchini) are the best to choose. Small vegetables like cress, mustard,
radish, spring onions and most herbs, are ideal for pot culture.
Whatever containers you choose, they
must have free drainage. Container grown vegetables cannot forage for
moisture as they do in the garden. In summer, vegetables may use several
times their own weight in water every day so this calls for daily
watering.
Leave a space of 3-5cm between soil
level and the rim of the container. Fill this space slowly until the
water weeps from the drainage holes. This restores the soil to 'field
capacity'.
