SELECTED VEGETABLE CROPS [continued]
Ch. 10, pp. 90 - 93
Crops: intro |
brussels sprouts |
cauliflower | sweet corn |
herbs | herb
||Deep, well drained loam.
||6.0 to 7.0
||Warm (60° F to 75° F)
||Seed after danger of frost is past; extra
sweet varieties should be planted when soil temperatures reach
||9 to 12 inches by 24 to 36 inches minimum of
three rows side by side (preferably four rows) to insure good
||Heavy feeder; sidedress when plants are 12
to 18 inches high with 3 tablespoons of 10-10-0 per 10-foot
Sweet corn varieties differ significantly in time to maturity and
in quality, yellow, white, bi-color, standard and extra-sweet
varieties are available. Most varieties planted are hybrids which
have been bred for greater vigor and higher yields. A continuous
harvest can be planned by planting early-, mid-, and late-season
varieties, or by making successive plantings of the same variety
when the previous planting is at the three leaf stage. Use only
the earliest varieties if growing season is short. Sweet corn that
matures during cool nights will almost always be the highest
quality, since it has an increased sugar content.
Pollination is a very important consideration in
planting sweet corn. Because corn is wind-pollinated block
plantings of at least 3 to 4 short rows will be pollinated more
successfully than one or two long rows. Good pollination is
essential for full kernel development.
Most of the various types of corn will cross-pollinate
readily. To maintain desirable characteristics and high quality,
extra-sweet and standard sweet corn should be isolated from each
other. A distance of 400 yards or planting so that maturity dates
are one month apart is necessary to insure this isolation. Sweet
corn plantings must be isolated from field corn and popcorn or
ornamental corn as well. White and yellow types will also
cross-pollinate, but the results are not as drastic.
The newly developed extra- or super-sweet types convert
sugar into starch more slowly than standard varieties. They are
not necessarily sweeter than just-picked old favorites (though
some cultivars are), but they will retain their sweetness after
harvest longer than usual. Super-sweet varieties may be less
creamy than standard varieties due to genetic differences. This
characteristic decreases the quality of frozen or canned
super-sweet corn though newer cultivars of extra-sweets show
Some gardeners are interested in growing baby corn such
as that found in salad bars and gourmet sections of the grocery
store. Baby corn is immature corn, and many varieties are
suitable, but Candystick, with its 1/4-inch diameter cob at
maturity, is a good one to try, especially since its dwarf habit
means that it takes up less space in the garden. Harvesting at the
right time is tricky; silks will have been produced, but ears are
not filled out. Experimentation is the best way to determine when
to harvest baby corn.
It is not necessary to remove suckers or side shoots
that form on sweet corn. With adequate fertility these suckers may
increase yield, and removing them has been shown in some cases to
actually decrease yield.
Mulching is a useful practice in corn growing because
adequate moisture is required from pollination to harvest to
guarantee that ears are well-filled. Since main crops of corn
usually ripen during drier periods, it is especially critical to
maintain soil water supplies, mulching reduces the need for
supplemental watering and keeps the moisture content of the soil
fairly constant. Most organic mulches are suitable; newspaper held
down with a heavier material on top is an excellent moisture
conserver in corn.
Normally, sweet corn is ready for harvest about 20 days
after the first silks appear. Pick corn that is to be stored for a
day or two in the cool temperatures of early morning to prevent
the ears from building up an excess of field heat, which causes a
more rapid conversion of sugars to starch. Of course the best time
to pick is just before eating the corn; country cooks say to have
the pot of water coming to a boil as you are picking the corn,
husking it on the way from the garden to the house! This is an
exaggeration, but with standard varieties, sugar conversion is
rather rapid. Field heat can be removed from ears picked when
temperatures are high by plunging the ears in cold water or
putting them on ice for a short time. Then store in the
refrigerator until ready to use. Extra-sweet varieties will also
benefit from this treatment, but they are not as finicky.
||Stewart's wilt (bacterial disease spread by
flea beetle); Smut (especially on white varieties) remove
infected part; Stunt (transmitted by leafhoppers).
||Corn earworm, southwestern corn borer, corn
seed maggot, flea beetles, Japanese beetles (eat silks), corn
sap beetles (damage kernels after husk is loosened or when ear
is damaged by corn earworm).
||Birds eating seed, raccoons eating mature
ears of corn, gardener's impatience (picking too soon). Cover
unharvested ears with a paper bag to prevent insect or bird
||Poor kernel development- failure to fill out
to the top; caused by dry weather during silking states,
planting too close, poor fertility (especially potassium
deficiency), too few rows in block resulting in poor
pollination. Lodging (falling over) from too much nitrogen.
HARVESTING AND STORAGE
|Days to Maturity:
||63 to 100 days.
||When husk is still green, silks dry brown,
kernels full size, and yellow or white color to the tip of the
ear. Harvest at the milky stage. (Test by puncturing a kernel
with thumbnail. If a clear liquid appears, the corn is
immature. If the liquid is milky, the corn is ready. If no
liquid appears, the corn is over-ripe). Experienced gardeners
can feel the outside of the husk and tell when the cob has
filled out. Corn matures 17 to 24 days after first silk
strands appear, more quickly in hot weather, slower in cool
||5 to 10 pounds (roughly 10-20 ears) per 10'
|Amount to Raise:
||20 to 30 pounds or about 40 to 60 ears per
||Refrigerate immediately to prevent sugars
from turning to starch; Cold (32° F), moist (85%
relative humidity) conditions, 4 to 8 days, but standard
varieties will become starchy after a few days.
||Frozen on or off the cob, canned.