Vegetable gardening
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Vegetable gardening is often viewed as
the poor relation of ornamental gardening. When we talk of great gardeners it
is far more likely their reputation was gained through their use of ornamentals
rather than vegetable production. This is a fairly recent turnaround, when
survival depended on horticultural skill it was far more important to be able
to produce good vegetables. Likewise herb gardening has come to be considered
quaint rather than practical because most of us no longer have a great need to
grow their own fresh herbs.
It wasn’t until the end of the nineteenth
century that ornamental gardens started to predominate but ever since then the
interest in domestic vegetable production has been waning. Increased leisure
time and new chemical fertilisers that boosted market garden output coincided
with increased urbanisation and the rise of ornamental gardening.
Given the choice most gardeners
concentrate on ornamentals. This is a pity because there are few more
satisfying aspects of gardening than the production of your own home grown
produce. With smaller gardens becoming the norm the area required for a
productive vegetable garden may seem excessive. However, many crops can be
grown in quite restricted spaces and the satisfaction of being able to harvest
fresh, home grown, vegetables is not to be underestimated.
Although vegetable gardening is often
seen as the preserve of elderly gentlemen it’s not essential to have a
lifetime’s experience to grow good vegetables. The important thing to
appreciate is that because most garden vegetables grow rapidly and take a lot
out of the soil it is vital to constantly replenish the humus and nutrients in
order to sustain production.
Maintain the soil’s structure and
fertility with plenty of compost and vegetable gardening is no more complicated
than knowing what to plant and when. The planting seasons over most of the
country fall into three distinct groups. The summer maturing
crops that are planted when spring is warm enough to allow them to grow.
The autumn and early winter crops that are planted around
midsummer and the winter to spring maturing crops that are planted from autumn
to early winter.
With regular crop rotation and the heavy
use of compost you should never be without at least a few fresh vegetables and
there will be times when you will have an absolute glut. Often the most
rewarding part of vegetable gardening is being able to give away your excess
produce to appreciative friends and relatives.
Very few vegetable crops do well in shade
and few will produce well on poor soil. Your vegetable garden needs to get
maximum sunlight while the bulk of your efforts need to go into improving, then
maintaining, the condition of the soil.
The following is a selection of common garden vegetables. Strictly speaking some, such as tomatoes, are fruits but they are usually included with the vegetables.
Artichoke
There are two quite different types of artichoke, the globe (Cynarus scolymus)
and the Jerusalem (Helianthus tuberosus). The globe artichoke is rather like a large thistle with edible flower buds. The Jerusalem artichoke is grown for its edible tubers.
Globe artichokes are usually raised from suckers taken from the base of proven plants. They can be raised from seed but with variable quality. The flower buds must be harvested while still tightly balled. Don’t just remove the bud, instead cut the entire stem back to about
half its length. At the end of the season cut the plant down to near ground
level and mulch around the roots.
Jerusalem artichokes are more straightforward. Plant the tubers in moist
well-drained soil in spring, apply a little fertiliser and harvest in autumn
once the tops have died back.
Asparagus
Asparagus is grown by divisions of its tuberous rootstock (crown). Plants can be raised from seed but only male plants produce an edible crop.
The fresh new growth shoots are the edible part. It takes several seasons for new crowns to become fully productive but once under way they are usually trouble-free. The cropping season is short but good beds are very productive. Thoroughly prepare the soil before planting. Work in plenty of compost material, enough to raise the bed, which will also ensure the good drainage, which is essential. In very heavy soils additional coarse sand or very fine shingle chips may be needed to improve the drainage. Harvest the young spears by cutting them off near ground level with a sharp knife. The smaller the spears when harvested the more tender they will be. Do not harvest any spears until the crowns are at least two years old.
Bean
The most common types of bean are the
dwarf, or French, and runner beans. They have similar foliage but dwarf beans
grow as low mounding bushes while runner beans climb to about 2 m high. Dwarf
beans usually have white or cream flowers, runners have bright orange-red
flowers. Dwarf beans are up to 125 mm long and roughly circular in section.
Runner beans are longer and flat. The beans of both main types should be
harvested before they become old and stringy. Eating raw runner beans can
cause stomach upsets.
There are several different styles of bean. Butter beans have yellow pods, French beans are green, Italian beans are fleshy but flattened like runners. Some of the bushy French beans will behave as climbers and can be trained to about 1.2 m high.
Plant in humus enriched well-drained soil in sun and keep the soil moist
or the beans will age prematurely. Plants are often raised from fresh seed each
year but runners will reshoot from the base. Experienced gardeners usually
replace their runner beans about every three years. Beans are rather prone to
caterpillar and other insect damage but such damage is often minor and quite tolerable.
Beetroot
This easily grown root crop is often undervalued. There are two main types, round and cylindrical, both with red or yellow flesh. Beetroot can be raised from seed but are frequently bought as young plants. The seed can be sown from spring to midsummer, and in mild areas autumn sowings may also be successful. Plant in well-fertilised moist well-drained soil in full sun. Any fertiliser deficiencies, particularly manganese, will show up as yellowing leaves and poorly formed roots. Very heavy soil will also lead to poorly formed and stunted roots.
Borecole
A cabbage family plant
that does best in cold areas. The foliage is
harvested in winter and used in the same manner as cabbage. Sow the seed in
October and November or set out young plants in early December. Several
cultivars are available. Borecole is not the most exciting vegetable but it
thrives in hard frosts and develops its best flavour under such conditions.
Broad bean
Broad bean seeds are sown in autumn; May
is quite early enough. The plants grow slowly over winter to be ready in early
to late spring depending on the climate. Spring sowings mature quickly but the
plants are usually very soft and are easily wind damaged. Sow the seed about 5
cm deep at 20 cm spacing. Planting in double rows is best as it makes staking
and tying easier. Drive in a stake at each corner of the block and along the
row if need be. As the plants grow tie twine between the stakes. Although the
beans may be used whole when very young it is more common to let them mature
and to use the individual beans, discarding the pod. Broad beans are prone to
fungus diseases that seem to be worse if the plants are handled while the
foliage is wet.
Broccoli
Green and purple sprouting broccoli may
be planted at any time but crops that mature in warm weather are likely to
flower before they can be used. Raise plants from seed or buy punnets of
seedlings. Seed sown in January will mature from late July to August depending
on the climate. A succession of planting from December to March will ensure a
steady supply. The heads should be picked when still quite tightly bunched but
the difference between immature and flowering is only a couple of weeks. Club
root can be a problem with broccoli; soil fungicides are effective
preventatives.
Brussel sprouts
Sprouts perform best in cool areas. Frosts bring out the flavour and cool weather prevents the sprouts flowering too quickly. The best sprouts are usually grown from Christchurch
southwards and in the central North Island. They prefer a reasonably heavy yet well-drained soil. Too much
rich compost or excess fertiliser will result in an abundance of foliage but
few flowering stalks. Spouts can be raised from seed sown from September to
October, however, it’s usually more convenient to buy
seedlings, which can be planted up to about the middle of November.
Water well during summer because any growth checks will lessen the
crop. Brussel sprouts are often damaged by aphids or white butterfly
caterpillars and as with any brassica club root can be a problem.
Cabbage
Apart from perhaps lettuces and tomatoes,
cabbages are the most widely grown vegetable. There are many varieties that
cover a range of sizes, foliage types and colours. By planting crops in
succession at intervals of a month to six weeks from early spring it is
possible to have plants maturing virtually all year. Cabbages can be raised
from seed but with only small quantities required at any one time bought
seedlings are generally more convenient. The time taken to reach maturity
varies considerably over the country but is seldom less than 100 days from seed
except for the very dwarf cultivars. Plant in soil that has
been worked to a fine tilth and water well during warm weather. White
butterfly caterpillars and club root are the most likely problems to be
encountered.
Cape gooseberry
Technically a fruit rather than a
vegetable but usually grown in the vegetable garden. At one
time very popular for eating fresh and for jam making but now not so widely
grown. May be raised from seed, which often self-sows, but it is often
easier to buy a few seedlings. Plant in a warm sunny position
with well-drained soil. Water and feed well. The fruit develops inside
papery calyces and is bright golden yellow to orange when ripe.
Carrot
Carrots are a common garden crop but they
require attention to the details of cultivation to be at their best. Sow the
seed in soil that has been worked to a fine tilth. Heavy soil will result in
poor root development. Although very fine the seed usually germinates well
unless the soil surface becomes caked hard.. However,
carrot fly, the larvae of which tunnels into the root, can
be a major problem. Late sowing (late November to January) lessens the problem
or soil insecticides can be used. These are applied at sowing time. Carrots
take about 80 days to reach maturity but can be used from a young age.
Cauliflower
A brassica that can be
planted in succession and harvested from winter to mid summer.
Seed is usually sown in trays and planted out as soon as it large
enough to handle. Transplant with care as cauliflower plants can be badly
damaged if roughly handled. Water well during warm weather and tie the foliage
over to the developing curd to protect it from hot sun or frost. There are many
cultivars. They vary in size and time to maturity but all are easily grown. The
usual brassica problems, white butterfly caterpillars, aphids and club root,
are likely to be the main difficulties.
Celeriac
Closely related to
celery and very similar in general appearance.
However, celeriac is grown for its edible roots rather than its leaf stalks.
Usually raised from seed sown in situ in spring. Most
loose well-drained soils are suitable. Later sowings will provide a succession
of fresh roots. The time to maturity is about 100-120 days. It is better to use
the roots before they are too large or they may become hollow. Celeriac is easy
to grow but may occasionally be attacked by the larvae of carrot rust fly. Soil
insecticides used at sowing time usually eliminate the problem.
Celery
Celery has a reputation for being
difficult to grow but the newer green and self-blanching cultivars are quite
straightforward. It’s true that germination is unreliable so bought seedlings
are usually the best way to establish a crop. Transplant carefully, and feed
and water well, especially when young. Any check in growth is likely to lead to
bitterness. Planting out can continue throughout the warmer seasons to provide
a succession of fresh stalks for harvest. Aphids and fungal leaf spotting are
common. They can be controlled with chemicals but the damage is usually tolerable.
Chicory
A perennial that can be found growing wild in many areas. It resembles a light blue flowered dandelion. Although now most commonly grown as a vegetable and a flavouring it has also been used medicinal. The long fleshy taproot is the part most commonly eaten but the leaves and flowers are also edible. Grows in any soil in sun or very light
shade. Raise from seed.
Chinese cabbage
The leaves of Chinese cabbage can be
eaten raw or cooked. Seedling plants are only rarely available in garden
centres so raising your own plants from seed is necessary. Germination is
somewhat unreliable, it’s best to sow the seed quite thickly and thin later.
The seed should not be planted deeply, 1-2 cm deep is
enough. Feed and water well, especially in hot weather. Easily grown and seldom
troubled by pests or diseases. Several cultivars are available.
Chives
A member of the onion
family grown for its edible foliage. Several
cultivars with differing leaf size and flavour are grown. Common chives have
very fine grassy leaves but garlic chives have broader strappy leaves up to 8
mm wide. May be grown from seed, bought seedlings, or by
dividing established clumps. Plant in well-drained
soil in full sun. Remove flower buds as they appear. Clumps should be
divided every two years or so.
Cress and mustard
Rapidly germinating annuals grown as
sprout and for their young leaves, which are used in salads. Mustard is also
grown for its seeds, which are often used in condiments. The seed germinates in
about three days and can be sprouted on moist paper towels for immediate use or
sown in the garden and the foliage or seed harvested when ready. Cress takes
about 5-7 days to germinate and can be used immediately. Wash the seed well and
sprout on moist paper towels. When grown for its young leaves simply scatter
the seed on the open ground and lightly rake in.
Cucumber
Cucumbers are very rapid growing
scrambling or climbing plants. They must have consistently warm weather and
ample moisture to perform well. Plant in a warm sheltered
position in soil that has been well manured and is high in humus. In
areas with cool nights cucumbers are best grown in greenhouses. However, their
need for high humidity makes them largely incompatible with other common
greenhouse crops, such as tomatoes. Once growing well regular
feeding and watering are all that is required. Cucumbers are mainly
differentiated by size. The smallest are the apple types, next come the medium
length, which are about 30 cm long, and then there are the long cucumbers, the
best known of which is ‘Telegraph’. Unless growing a self-fertile cultivar,
such as ‘Farbiola’ it’s necessary to have at least two plants for good
pollination. Cucumbers are sometimes grafted onto vigorous rootstock. Such
plants can become very large and are heavy cropping. The larger the cucumber the
longer it will take to mature. Cucumbers are not very prone to pests but virus
diseases can be a problem. Avoid repeatedly growing cucumbers in the same soil
unless it is sterilised each year. Cold draughts and irregular temperatures are
the main reason for failure.
Eggplant
Really a fruit rather than a vegetable,
the ‘Aubergine’ or ‘Eggplant’ is a member of the potato family. Plant after any
frost danger has past in a warm sheltered position with deep rich well-drained
soil. Usually espaliered against a sunny fence or wall, or grown in a
greenhouse. Regular liquid feeding and ample moisture during the growing season
will ensure that the fruit develops to a good size. Do not allow too many fruit
to develop on one plant. Any more than ten is likely to result in reduced fruit
size. The fruit is ripe when it becomes deep blackish purple, the flesh will be
bright golden yellow.
Endive
Now seldom grown but once a popular alternative to lettuce, particularly in areas where lettuce failed to grow well in summer. Endive grows in any well-drained soil. Pests and diseases seldom cause any major difficulties. Raise from seed, which may be sown from spring to autumn. The seed may be sown in situ or raised in trays then transplanted. The leaves are picked while still quite young. They
can be eaten raw or boiled like cabbage. As the plants age
they become bitter. Blanching, by covering the plant, improves the
flavour but is a troublesome process and doubtless accounts for the decline in
popularity.
Garlic
Once regarded as vaguely foreign and distinctly un-British garlic is now widely grown and enjoyed. It is a member of the onion family that grows well in any well-drained soil in full sun. May be raised from seed but usually started by breaking off a clove and planting it.
The cloves should be planted with the upper tip (the pointed end) at, or just
below, soil level. Garlic takes up to six months or more to mature so cloves
planted in early spring will not be ready until autumn. As the bulb matures the
foliage dies back. At that point cease watering and allow the bulbs to dry and
harden. Once all the foliage has dies back harvest the bulbs, complete the
drying process and store as you would onions. Garlic is an easily grown and
very useful crop.
Horseradish
An extremely vigorous perennial that even the most dedicated devotees of horseradish source should think twice about before introducing into their gardens. The tough white roots are used to prepare the well-known condiment. Very easily grown in any soil in sun or light shade.
Propagate by dividing established clump, however, this is seldom necessary as once you have it you have it for life.
Kale
A brassica crop that is
usually grown over winter. It is used in exactly
the same manner as cabbage. Ornamental varieties with brightly coloured foliage
are often used as winter bedding plants. The seed may be sown from early summer
to mid autumn. Crops intended for consumption are best started early but those
grown as ornamentals can be delayed to provide a longer season of colour. Very
easily grown but subject to the usual brassica problems, white butterfly
caterpillars and club root.
Kohl rabi
A brassica grown for its edible roots, which are swollen and resemble swedes. Its main use is as a winter vegetable. To mature in winter the seed
should be sown around February. Seed can be sown throughout the year but few
gardeners find kohl rabi interesting enough to give it
space in the summer garden. Kohl rabi grows in any
well-drained soil and should be kept growing steadily, any growth checks will
result in bitterness. The plants mature in 2-3 months. The roots will become
very large if allowed but are best used when young. As they become older the
roots develop a very strong flavour.
Kumara
The ‘Sweet Potatoes’ are more closely
related to the morning glory vines than the true potatoes. The edible
potato-like tubers that give them their common name require a long warm season
to reach maturity. Light well-drained soil is best for kumaras. A large area is
required as the tops grow very strongly. The usual growing procedure is to
sprout the tubers in boxes of warm moist soil in a greenhouse or some other
sheltered area then plant them out. In mild northern areas the tubers can be
planted out directly, without sprouting. Once underway the plants grow rapidly.
The tops will strike roots as they spread, which reduces tuber size, unless
they are regularly lifted from the soil surface. A routine part of kumara
growing is to disturb the tops every few days to prevent them
striking roots. At the end of the season the tubers can be lifted and used, or
stored. To store kumaras first dry them off in a sunny
well-aired place then put them in boxes of dry sand or sawdust. Stored loose
they are liable to bruise or be otherwise damaged, which rapidly leads to
rotting.
Leek
Leeks are a vegetable that has declined
in popularity in recent years to the extent that growing good leeks is becoming
something of a lost art. It’s not that leeks are difficult to grow, quite the opposite,
but many new gardeners simply do not use enough compost or fertiliser. Leeks
demand a rich soil with plenty of organic matter. The seed may be sown from
spring to early autumn in most areas. However, bought seedlings are the normal
method of establishing a crop. The seedlings can be planted out from spring
until early winter, in mild areas. Modern varieties are largely self-blanching
but better results are still obtained by mounding the soil around the stem as
it matures. Leeks need regular watering and feeding but are usually otherwise
trouble-free.
Lettuce
Lettuce is almost certainly the most
widely grown vegetable crop. It matures quickly and in many areas may be
planted year round. There are two main forms, heart-forming and
non-heart-forming. Heart forming lettuces develop densely packed central
leaves. Usually the whole plant is cut and used when mature. Non-hearting
lettuces can be used as they grow, a few leaves picked as required. Both forms
come in the traditional green leafed or the increasingly popular red leafed
style. Red leafed lettuces tend to have a stronger flavour. Lettuces are not
fussy about soil type but they must have a steady supply of moisture and
nutrients. Composting and fertilising before planting is best but liquid feeding
is also very beneficial. Plants that grow slowly or that suffer from drought or
nutrient deficiencies are likely to become bitter tasting.
Lettuces are not difficult to grow but
they are subject to pests and diseases. Birds will destroy young plants that
are not covered with netting or other protection. Slugs and snails often damage
the foliage. Rotting can be a problem too if the weather is very wet or humid.
However, a little protection when young is all that is usually required to
ensure a good crop.
Marrow and courgette
Very easily grown cucurbits. Marrows are now rather unpopular but
courgettes, which are really just small marrows, are widely used. All
courgettes will develop into marrows if not harvested when young but not all
marrows are suitable for picking young. Seed should be sown in spring,
preferably indoors to give it a quick start. The young seedlings should not be
planted out until the soil is warm and all danger of frost has past. When young
the plants grow rapidly and need plenty of moisture and feeding. Marrows
usually require the whole season to reach full size and to ripen but courgettes
can be harvested throughout summer. Regular picking will encourage continued
flowering and fruiting. In humid areas mildew can be a problem but provided the
weather is warm enough to keep them growing steadily these plants are usually
trouble-free.
Melon
Melons need consistently warm weather
over a long season to ripen properly. They are only rarely successful outdoors
in areas south of Marlborough. Young plants should be started under cover. The seed may be sown
in early spring and the young plants set out when the soil has warmed and any
danger of frost has past. Melons should be grown as quickly as possible. If the
weather is warm it is very difficult to overwater or overfeed
them. The plants will cover a large area by the end of the season. Once the
fruit starts to form it is important to prevent it from rotting. Raise the
fruit by placing it on boards, mounds of dry straw or similar material. As the
end of the season nears and the fruit is ripening cease watering and feeding.
The fruit will ripen as the vine withers. Rock melons separate from the vine
when ripe but it can be difficult to tell when watermelon is ripe, experience
is the best guide. Although they need plenty of moisture when
young melons can develop fungal diseases in very humid conditions. Avoid
getting water on the foliage and fruit if possible and ensure that the plants
are well ventilated but away from cold draughts.
Okra
Okra is, strangely enough, a hibiscus, Hibiscus esculentus to be
precise. It is grown for its edible seed pods. The pods must be used
young as they rapidly become very stringy. Okra grows best in a rich, moist,
well-drained soil in full sun. The young plants are very tender so they are
usually started under cover and planted out when all danger of frost has past.
The plants grow quickly in areas with warm summers but fail to do well if
exposed to cold draughts or variable temperatures.
Onion
To ‘know your onions’ may mean that
you’re fairly knowledgable but that doesn’t mean that onions are difficult to
grow. There are many types but they all fall into two basic categories, those
to be used immediately and those that will keep for several months. Onions are
usually raised from seed or bought as young seedlings ready fro planting out.
In mild areas the seed can be sown in autumn and spring but spring is the main
sowing season. The seed be should be well-worked but
not too light and dusty. The seed is usually sown quite thickly and thinned
later to allow the bulbs to mature. The thinnings can be planted elsewhere or
used as spring onions. The soil should be kept moist while the bulbs mature but
excessive watering and extended periods of humid weather can lead to mildew.
Thrips are also a problem in some areas.
Non-keeping onions can be used at any
time during the season but keepers are left to mature naturally. As the bulbs
mature the tops begin to die back. Once the tops have died off the onions
should be lifted and dried. When the skins are properly dried the onions can be
strung up in the traditional manner or stored in string bags.
Shallots are small onions. There are two main types, French, which are
usually eaten raw, and the larger Russian, which are usually pickled. Shallots
are treated much like garlic. Grow by planting the offsets (cloves) in
well-drained soil in full sun. They are usually planted around mid-winter. They
are ready when the tops die back, which is usually from late December to early
January. The bulbs are dried and stored in the same way as onions. Mildew and
thrips are the only problems of any significance.
Parsley
A clump forming
biennial that is grown for its foliage, which is used as a garnish.
It has a tough taproot that is larger in some cultivars, such as
‘Tuberosum’. The roots of ‘Tuberosum’ are the size and shape of a small parsnip
and can be cooked or eaten raw. Parsley prefers to grow in cool moist soil in
light shade. Raise from seed, which germinates quickly
provided it is fresh.
Parsnip
This root vegetable is easily grown in
most well-drained soils. It is raised from seed, which is sown in spring and
summer to mature from early autumn. The seed must be fresh or germination will
be very erratic. Sometimes the seedlings have difficulty pushing through the
soil surface. Mixing in a few quick germinating seeds, such as radish or
mustard, with the parsnip seed helps to break the soil crust. Provided the soil
is well-drained parsnips hold well over winter if left in the ground. They
develop their best flavour when exposed to frosts. Once
germinated parsnips are fairly trouble-free. Early sowings may be
damaged by carrot rust fly larvae, which can be controlled with soil
insecticides.
Pea
Fresh peas are marvellous but the pods
age quickly and frozen peas are far more convenient consequently peas are now
not very regularly grown in domestic gardens. Peas are not difficult to grow.
They are climbing plants so some form of support is necessary. Wire netting
attached to stakes is the most common method. The soil should be prepared well
before planting. Work in plenty of compost and a general fertiliser. Acid soils
will benefit from a light dressing of lime. Sow the seed in spring, in very
mild areas autumn sowings are also possible. The soil should be reasonably warm
or gemination may be erratic. Soak the seed for a few hours before sowing.
Plant at about 5 cm depth. It is usual to plant in double
rows so that the two rows can support one another. The peas should be used as
soon as they are large enough, they quickly become
hard and chewy so don’t hesitate to use them young. The pods of some varieties,
such as ‘Sugar Snap’ are edible. Peas are often damaged by mildew and may
occasionally be attacked by aphids. Birds often eat the
young seedlings as they emerge from the soil.
Peanut
Something of a novelty crop and one that
needs a long warm summer to mature properly. The plants resemble small sweet
peas but after flowering an unusual structure develops at the base of the
flower. This ‘peg’ grows down to ground level and then into the soil. The
subterranean tip develops into the peanut, which is ready about 120 days after
planting. Obviously this type of growth habit demands a reasonably loose soil,
preferably one that is sandy. Peanuts may be grown by simply planting the raw
peanuts that are available at any supermarket.
Pepper
Peppers (capsicums) come in several
different types. The most familiar are the rounded bell pepper, which starts
out green and ripens to red (or black), the slightly spicy yellow Hungarian pepper
and the very hot long thin chilli peppers. The plants may be raised from seed
but it is more common to buy young seedlings. They should be kept under cover
until any danger of frost has past. Grow in humus enriched moist well-drained
soil in sun. Shelter the young plants from cold draughts. In areas with cool
summers it may be better to grow your peppers in a greenhouse. The plants grow
rapidly and crop heavily for their size. Peppers usually pose no great
cultivation difficulties but they may need staking and plants grown indoors are
often attacked by aphids.
Potato
Which is the best potato? Among vegetable
gardeners no other topic provokes such earnest debate. Whatever
your choice, large, small, yellow, white or red, there’s no
doubt that potatoes are a staple. They take up a significant amount of space,
which may be a consideration in a small garden, but they are a crop that is
certain to be used and appreciated.
The soil should be humus enriched and
well-drained. Work in plenty of compost well before planting and apply a
general fertiliser. Potatoes can be raised from the true seed but are generally
grown planting small ‘seed’ potatoes. Experimentation and the advice of garden
centre staff will soon tell you which varieties are best for your soil. Whichever
variety you choose buy only government certified seed potatoes. These are true
to type and should be free of viruses.
The seed tubers are spouted from late
winter by putting them in a well-lit airy position that is frost free. They can
be planted out in early spring if the soil is not too wet. Time
your planting so that the tops do not emerge above soil
level until the frost danger has past. Plant in a furrow that
is about 10-12 cm deep. Fill the furrow by raking the soil back over it
to create a mound. By continuing to mound up the soil as the foliage emerges a
greater area of roots, and hence more potatoes, can be developed.
Some potatoes keep better than
others, these are known as main crop potatoes. They are usually
left until fully mature (when the tops have died back) before harvesting. New
or early potatoes are harvested and used as soon as they are ready. Some
cultivars, such as ‘Chippewa’ can be used for both purposes.
Potatoes are subject to fungal diseases known as ‘blights’. They are also likely to rot if the soil remains wet after heavy rain. Good soil conditions and ventilation are the best ways of preventing disease.
Pumpkin and squash
Pumpkins are very rapid growing plants
that can quickly cover a large area. Squash is more restrained but still
requires a large area. Both are best grown a well-drained humus enriched soil
in full sun. The old method (and still one of the best) for raising pumpkins
was to sow the seed in a patch of warm compost but starting the seeds in pots
is neater and more convenient. Provided all danger of frost has past and the
plants are not exposed to cold draughts there should be little difficulty in
growing pumpkins or squash. Feed regularly with liquid fertiliser and make sure
that the fruit is not sitting on wet soil. Mildew and botrytis sometimes occur
in humid areas. Some cultivars are better keepers than others but this makes no
difference to their growth requirements.
Radish
An extremely easily grown root crop. The seed germinates quickly and the seedlings mature in about 3-4 weeks. For best results sow on loose well-drained soil that has plenty of compost worked in. In mild areas radishes can be sown at monthly intervals throughout the year. Where the winters are very cold the seed will not germinate in winter but autumn sowings will
withstand early frosts.
Rhubarb
Rhubarb is a very unusual plant: a tuberous rooted perennial grown for its edible leaf stalks. It grows best in moist, humus enriched well-drained soil in sun or partial
shade. The foliage dies back completely in winter, when the roots can be
divided, and grows back rapidly in spring. The leaf stalks are ready to eat
when they have developed the characteristic red colour. Any flower buds should
be removed as they appear. Rhubarb is generally trouble free but benefits from
regular feeding and division every two or three years.
Salsify
Salsify is a relatively uncommon root
crop. It prefers a rich well-drained soil and benefits from occasional liquid
feeding while growing. Raise from seed, which can be
sown at any time except from about mid January to April. Autumn sown seed will
remain as small plants until spring and then grows quickly. The roots are ready
for harvest about 4 months after sowing but the time to maturity will vary
considerably depending on the season and the climate. Apart from possible
carrot rust fly larvae damage on spring sown seed salsify is very easily grown.
Silverbeet
Silverbeet is leaf crop widely grown as
an alternative to spinach. The large deep green glossy bullate leaves are the
edible part. The seed may be sown throughout the year in mild areas but may be
difficult to germinate where the winters are very cold. Bought seedlings are
often the best way to establish the crop and ensure a succession of tender
young leaves. A rich moist well-drained soil will give the best results but
silverbeet will grow almost anywhere. The seed should not be sown too deep (2
cm) and young plants should be protected from snails, slugs and birds,
otherwise silverbeet is largely trouble-free. Rust can be problem in humid
weather but usually only attacks plants that are grown under less than ideal
conditions.
Spinach
A very easily grown leaf crop that is high in iron. Spinach should be grown in humus enriched moist well-drained soil. Work in plenty of compost well before planting and add a general fertiliser. Spinach is planted in the autumn and matures in winter or early spring. New Zealand spinach is a similar plant that is planted in spring to mature in summer. Apart from slug and snail damage there are no particularly troublesome pests or diseases.
Swede
Swede is a variety of turnip with a
particularly large rounded root. They grow in most soil types but benefit from
the addition of a general purpose fertiliser prior to planting. The seed is
sown from late spring to mid summer. Autumn sowing is possible in areas with
very mild winters. The plants mature in about 3 months but will keep in the
soil over winter provided the drainage is good. Aphids and white butterfly
caterpillar may damage the foliage but the plants can usually withstand such
attacks.
Sweet corn
One of the traditional tastes of summer. Sweet corn is probably the only cereal crop to be grown in the domestic garden. It is raised from seed, which is sown in spring once the soil has warmed (around 15°C), or from bought seedlings, which may be planted out once all danger of frost has past.
Plant in humus enriched soil in full sun.
Perfect drainage is essential. The young seedlings grow only slowly to start
with but once the days near maximum length they begin to grow rapidly.
Ultimately the plants may be over 2 m high. Because of their height, which can
lead to wind damage, and because of their pollination requirements it’s best to
plant sweet corn in blocks or at least double rows.
The corn cobs are usually ripe once the
flower tassels have withered and dried. The cobs soon become hard and chewy so
check out a few cobs before the tassels dry fully just in case they’re ready to
harvest. Sweet corn is not particularly prone to diseases but the cobs are
sometimes damaged by caterpillar, although rarely to the extent that control is
necessary.
Tomato
It’s every vegetable gardener’s objective
to grow the best tomatoes. There are many different cultivars, enough for the
most discerning connoisseur. They range in size from tiny cocktail tomatoes to
huge beefsteaks. The fruit can be round, cylindrical
or deeply lobed. The colour can be yellow, orange, red or striped and they can
be low acid and bland or extremely tasty.
Tomatoes may be raised from seed but as
the quantity of plants required is usually not great it is more common to buy
seedlings from a nursery or garden centre. Take care to choose the cultivar
that best suits your requirements. Do not plant your tomatoes until the soil is
warm and all danger of frost has past.
Most tomatoes are upright plants that
should be staked or grown against a wall or fence. However, a few are low and
bushy. Bush tomatoes are easily grown but the fruit often forms under the foliage
and is difficult to ripen or it rots through sitting on wet ground.
Upright tomatoes should be encouraged to
grow straight up by removing any side shoots (laterals) that form in the leaf
axils of the main stem. Take care not to remove the flower stems or damage the
growing tip. Once the plant has reached as high as is practical the growing tip
can be pinched out and a lateral or two allowed to develop.
Some tomatoes are grafted onto very
vigorous rootstocks. These plants are treated as climbers. They are grown
against a fence or on a series of stakes. Remove the lower laterals but train
two or three out either side of the main stem. Grafted tomatoes can become very
large plants and often crop extremely heavily.
Tomatoes respond to regular feeding.
Special tomato fertilisers are available. They are usually divided into two
types, a base mix to be used prior to planting and a side mix to be used on
growing plants. Liquid feeding is also beneficial. However do not overwater
your tomatoes. Young plants need just enough moisture to keep them standing up.
Once the fruit has set it is important to make sure the soil moisture is even
but not excessive. Watering then allowing the soil to dry can cause the tomato
skins to split. Irregular watering and water on the fruit can also lead to a
fungus disease known as blossom end rot.
Several pests and diseases damage
tomatoes. Virus diseases are the most devastating, they are invariably fatal.
Do not plant tomatoes in the same position year after year or if you must then make
sure the soil is sterilised each year. Fungus diseases, such as mildew and
botrytis, can usually be traced to poor ventilation and overwatering. Looper
caterpillars are often a major pest late in the season. Most fungicides and
surface acting insecticides are suitable for tomatoes.
Turnip
Turnips are brassicas grown for their
edible roots. They are easily grown but appreciate a rich well-drained soil.
Turnips are inclined to become woody or bitter if they suffer any checks to their
growth. Although the seed can be sown from spring to autumn it is the mid
season and later sowings that generally do best. The plants take about 3 months
to mature and are better if used young rather than being allowed to become old
and woody. The seed may germinate poorly if sown too deeply (1-2 cm is ample)
or if the soil surface becomes caked otherwise turnips are usually
trouble-free.
Watercress
A perennial salad herb that is also
valued for its medicinal properties. Grows in wet soil or shallow water and
often found growing wild. Not always easy to cultivate because of its high
moisture requirements. If you don’t have naturally wet areas then pots that can
be kept very moist are probably the best option.
Yam
Yams are the tubers of a genus of tropical
semi-climbers. They are easily grown but frost tender so they should not be
planted out until the soil is warm and any danger of frost is past.
Pre-sprouting tubers in boxes of warmed soil gives the plants a quick start but
in most areas it’s not really necessary. Yams should be grown in humus enriched
moist well-drained soil in full sun. In most areas they are relatively
trouble-free. harvesting the tubers should be left as
late as possible. In most areas they are harvested when the tops are cut back by
frost. In mild areas they can often be left well into winter provided the
drainage is good.
Copyright Geoff Bryant
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