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Vegetable growing at
home is not without its grumbles. The yield of
pea pods is sometimes disappointing for the amount
of work expended whereas broad beans present the
opposite problem – a sudden glut which often
goes to waste. Onions, however, present neither
of these problems – few vegetables have
more uses in the kitchen and so there is a constant
demand. Nowadays we can obtain onions fresh from
the garden or out of store almost all year round
from just a couple of carefully-timed sowings.
But we are creatures of habit – both peas
and broad beans are two of our top-selling vegetable
seed and onions are not. If onions are not on
your list read this section carefully –
the new Japanese varieties have filled the June-July
gap of the old days, and the new close-spacing
recommendation increases the yield.
Seed facts
Fungicide-treated and pelleted seeds are available.
Germination and seedling growth are slow in spring
and also erratic in hot weather.
Expected germination time: 21 days
Approximate number per ounce: 8000
Expected yield from a 10ft row: 8lb (4kg)
Life expectancy of stored seed: 1-2 years.
Approximate time between sowing and lifting: 46
weeks (August-sown varieties); 22 weeks (Spring-sown
varieties).
Ease of cultivation: Easy – if a suitable
seed bed is prepared.
Soil facts
· Many exhibitors grow their show onions
in a permanent bed in order to build up fertility,
but in the kitchen plot it is a much better idea
to change the site annually.
· Choose an open, sunny site with good
drainage. Dig thoroughly in autumn, incorporating
a liberal quantity of manure or compost. Liming
will be necessary if the soil is acid.
· Before sowing or planting it is necessary
to prepare a traditional ‘onion bed’.
Apply a general fertilizer and rake the surface
when the soil is reasonably dry. Tread over the
area and then rake again to produce a fine, even
tilth.
Sowing and Planting
· Sow very thinly in drills 1/2in (1cm)
deep and 9in (23cm) apart. Water very gently if
the soil is dry, and cover with soil.
· Thin the spring-sown crop in 2 stages
– first to 1-2in (2-5cm) when the seedlings
have straightened up and then to 4in (10cm) apart.
Lift the seedlings carefully – the soil
should be moist and all thinnings removed to deter
onion fly.
· Seedlings raised under glass should be
transplanted 4in (10cm) apart, leaving 9in (23cm)
between the rows. The roots must fall vertically
in the planting hole and the bulb base should
be about ½ in (1cm) below the surface.
Plant firmly.
· Salad onions should be planted in rows
which are only 4in (10cm) apart – thin the
seedlings, if necessary, to 1in (2.5cm) spacings.
· Seeds of Japanese varieties should be
sown at 1in (2.5cm) intervals in rows spaced 9in
(23cm) apart. Thin seedlings to 4in (10cm) intervals
in spring.
Calendar
· For an August or September crop sow as
soon as the land is workable in the spring (late
February-early April depending on the location
of your garden).
· Sow in mid August for an earlier crop
– Japanese varieties mature in late June
– standard varieties such as Reliance and
Ailsa Craig are less hardy, less reliable and
later cropping (late July onwards), but they can
be stored.
· In cold areas and for exhibition bulbs
sow under glass in January, harden off in March
and transplant outdoors in April.
· Salad onions should be sown in March-July
for a June-October crop. Sow in August for onions
in March-May.
Looking after the crop
· Hoe carefully or weed by hand –
dense weed growth will seriously affect yield.
Water if the weather is dry (not otherwise) and
feed occasionally. Feed an autumn-sown crop with
Instant Bio in March.
· Break off any flower stems which appear.
Mulching is useful for cutting down the need for
water and for suppressing weeds. Stop watering
once the onions have swollen and pull back the
covering earth or mulch to expose the bulb surface
to the sun.
Harvesting
· The salad varieties should be pulled
when the bulbs are ½ - 1in (1-2.5cm) across.
The harvesting season is March-October.
· When the bulb is mature the foliage turns
yellow and topples over. Leave them for about
2 weeks and then carefully lift with a fork on
a dry day.
· The onions which are not for immediate
use must be dried. Spread out the bulbs on sacking
or in trays – outdoors if the weather is
warm and sunny or indoors if the weather is rainy.
· Drying will take 7-21 days, depending
on the size of the bulbs and the air temperature.
Inspect the bulbs carefully – all damaged,
soft, spotted and thick-necked onions should be
set aside for kitchen use or freezing. The rest
can be stored – the exceptions are the Japanese
varieties which are not suitable for storage.
· Store in trays, net bags, tights or tie
to a length of cord as onion ropes. Choose a cool
and well-lit place; they will keep until late
spring.
Varieties
Bulb varieties
The standard varieties are grown for their large
bulbs which can be stored throughout the winter
months. Some have a flattened shape, others are
globular. Skin colours vary from almost pure white
to bright red and flavours range from mild to
strong. Most of them are only suitable for spring
sowing but some can be sown in August for a late
July crop. The Japanese varieties make late summer
sowing a much more reliable routine but their
midsummer crop cannot be stored.
Ailsa Craig: Look no further, according to some
experts. A great favourite – very large,
globe-shaped, and excellent for exhibiting but
its keeping qualities are not good.
Bedfordshire Champion: Very popular – scored
over Ailsa Craig by being a good keeper. Large
and globular, but very susceptible to downy mildew.
Rijnsburger: The catalogues list many strains
– Balstora, Wijbo, Bola, etc. Large, globular,
white-fleshed – earliness and keeping qualities
depend on the strain you choose.
White Spanish: A large, flat bulb with excellent
keeping qualities.
Hygro: An F1 hybrid which is increasing in popularity.
No faults – heavy, globular, and suitable
for storage.
North Holland Blood Red: A red-skinned onion –
a good choice if you want a colourful onion for
exhibition.
Buffalo: A new F1 hybrid which produces a very
early crop from a spring or late summer sowing.
Onions in June, claim the catalogues, but you
won’t be able to store them.
Autumn Queen: Flattish bulbs for autumn sowing
– recommended for exhibition.
Reliance: Perhaps the best of the standard varieties
for sowing in August. The flat bulbs are large
and the keeping qualities are outstanding.
Express Yellow: The most popular and earliest
of the Japanese varieties. The flattish bulbs
are yellow-skinned. Choose one of the other Japanese
type if you want maximum yields.
Kaizuka Extra Early: Like Express Yellow the bulbs
are flattish, but the skins are paler and they
mature a little later.
Imai Yellow: A Japanese variety which is globe-shaped
and early.
Senshyu: Rather similar to Imai Yellow, but a
little flatter and later cropping.
Salad varieties
Thinnings of the bulb varieties can be used as
salad or ‘spring’ onions, but there
are several varieties which are grown specifically
for salad use. These salad varieties, also known
as scallions or bunching onions, are white-skinned
and mild-flavoured.
White Lisbon: By far the most popular of the salad
varieties. Quick-growing and silvery-skinned,
a small patch of ground can provide salad onions
for six months of the year.
Ishikura: Something new in salad onions. The long,
straight stems do not form bulbs – simply
pull out a few at a time and let the rest of the
pencil-like plants grow on for harvesting later.
Pickling varieties
Several onion varieties are grown for their small
silverskin bulbs (button onions) which are lifted
in July or August and pickled for use as cocktail
onions. These varieties should be sown in April
in sandy soil – do not feed. The seedlings
should not be thinned.
Paris Silver Skin: The favourite pickling onion;
lift when the bulb is the size of a marble.
Barletta: Another popular variety for making cocktail
onions – no particular advantage or disadvantage
compared with Paris Silver Skin.
Troubles
Although many plant disorders can attack onions,
only four are likely to seriously trouble the
gardener. They are onion fly, stem and bulb eelworm,
neck rot and white rot. Plants grown from seed
are more susceptible to onion fly, so raise onions
from sets if you have been disappointed in the
past. Leeks are much less prone to attack than
onions.
Onion Fly
Drooping Leaves
Bolting
Stem and Bulb Eelworm
Saddleback
Set Division
Smut
Rust
White Tip
Bull Neck (Thick Neck)
Downy Mildew
Leek Moth
White Rot (Mouldy Nose)
Shanking
Neck Rot
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