April 2012 column from Oak Park Community Garden, sumitted to
oakparkupdate.com and oakparknow.com.
IT'S APRIL. READY TO PLANT SWEET CORN?
Before we get into the details of sweet corn, here's
a word of encouragement if you forgot to plant your summer vegetables
last month. Not to worry. Lots of veggies like being planted in April.
Among them are green beans (see last
month's column) beets, carrots,
corn, endive, leaf (not head) lettuce, New Zealand spinach, pumpkins,
radishes, salsify, squash, sunflowers, Swiss chard, and turnips. Put
in cucumber and tomato transplants. (See how to support tomatoes here). About
that New Zealand spinach—don't plant it unless you love it, because
after you tear it out—it keeps coming back from seeds, especially
in interior zones. Ok. That said, here we go...
HOW TO GET A HUGE HARVEST OF SWEET CORN
- Choose a good variety. Try "How Sweet it Is"
or "Kandy Korn." Buy enough seeds for successive plantings of 12 to
20 plants at a time.
- Spade the ground deeply in a square area, in
full sun, north of shorter crops. (Corn is pollinated by wind. Pollen
from the male flower must fall on the female silks, so plant in
a block rather than a long skinny row. Mix organic soil amendment into
the ground and cultivate organic vegetable fertilizer (6-12-6 is good)
into the top 6 inches according to package directions.
- Set up a drip system designed for row crops
running north to south, 3 feet apart (18" apart if you're space is
limited). Mound the rows 4" high and 8" wide between furrows that are
to be used as paths.
- Except in the hottest areas, cover the entire
area with black, not clear, plastic sheeting as mulch, to increase
heat and yields.
- For supersweet varieties, presprout the seeds
indoors over bottom heat (see the "How To" box below). Supersweet varieties
have a "shrunken gene" that causes their seeds to be shriveled and
difficult to germinate if soil is cool.
- As soon as the seeds sprout, plant them 2 inches
deep and 12 to 18 inches apart in each row. (If the rows are only 18
inches apart, use the wider spacing within rows for a bigger harvest.)
For each, use a razor blade to slice a 4-inch-square X in the plastic
mulch, make a 2-inch-deep hole with your finger, then put the seed
in with the root pointing down and the sprout pointing up. Press the
soil gently back together. Fold the cut edges of plastic under and
slip the lower edge of an upside-down berry basket into the slit area
to protect the seed from birds. (The berry basket will exactly fit
the squre space you have cut and be held firmly in place.)
- Water with a drip system—daily in sandy soil
or twice or three times weekly in clay soil—until sprouts emerge. Gradually
lengthen spacing between waterings until you're watering deeply and
well about every three days in sandy soil, once a week in clay.
- When the leaves reach the tops of the berry
baskets, remove the baskets. Plant more corn in two weeks, and feed
the first batch with fish emulsion.
the corn tassels out, give it extra water and feed it thoroughly with
a balanced liquid fertilizer—for example, fish emulsion containing
the whole fish, such as Neptune's Harvest (2-4-1), mixed double-strength,
or alfalfa or manure/compost tea. (See compost tea recipe at the end
of this article.) Pour it around plants with a watering can or, using
a water wand attached to a siphon, soak the ground under the plastic
with it. If you prefer to use granulated fertilizer, apply organic
vegetable fertilizer according to package directions when the corn
is 12 to 18 inches high and gain when it is 24 to 30 inches high. Or
use fish meal, an ideal fertilizer for corn (as we know from Squanto's
advice to the pilgrims).
- For full ears in a small plot, hand-pollinate.
When tassels bloom with dusty pollen, break off sections and whip them
on the silks at the tops of the ears (To activate growth in every kernel,
each silk needs one grain of pollen.)
TO PRESPROUT SEEDS FOR A FAST START WITH NO ROT
seeds, planted in the ground, may rot instead of growing. Examples
are any beans planted in cold, wet soil, some varieties of sugar
peas that have shriveled-looking seeds, and supersweet barieties
of sweet corn that have shriveled seeds caused by the "shrunken"
gene that makes them so seet. In these cases, it's easy, timesaving,
and worthwhile to sprout seeds indoors. Here's how:
- Wet a paper towel. Squeeze it out
and spread it flat. Place a few mre seeds than you need on
half the towel, arranging them so they don't touch one another.
Bend the other half over. Put the whole thing, flat, in a
zip-locked plastic bag and seal it up.
- Place the plastic bag containing the
paper towel and seeds over bottom heat at approximately 70°F.
Possible heat sources include low-wattage liht bulbs, radiantly
heated floors, antidampness bars used to keep closets, towels,
and pianos dry, heat fents, water heaters, or even the tops
of TVs or VCRs. (If a light bulb or heating bar is used, elevate
the seeds on a cookie sheet or metal tray to diffuse the heat.)
- Check your seeds daily; add moisture
if needed. Bean seeds sprout in about three days, corn and
peas in four or five. As soon as they sprout, plant them in
the garden. Handle them bently; don't break their roots.
- To plant, make a hole with your finger
deep enough for the think white root to go straight down; the
thicker, yellowish sprout should point up. (In cool weather,
plant the seed only an inch deep. After the sprout comes up,
you can mound the soil higher around it.) Press the soil gently
but firmly from the sides to make good contact. If some sprouts
fail to come up, presprout more and replant to fill gaps in
WHY SOME SWEET CORN VARIETIES MUST BE ISOLATED
FROM OTHER VARIETIES
Because each kernel is individually pollinated
by wind, corn easily crossbreads when different varieties that mature
at the same time are planted closely together. Sweet corn, popcorn, field
corn, and ornamental varieties can all interbreed. For this reason, it's
best to plant only one variety of sweet corn in staggered plantings or
to plant an early, a mid-season, and a late variety so that they will
not produce pollen at the same time. Be particularly careful when planting
AE and SH2 varieties. (See box below.) Also, when planting
popcorn and orrnamental corn, make sure maturity dates are different
from all other corn varieties you'll plant. Pollination between two different
types of corn will make your corn starchy and bland tasting.
SWEET CORN VARIETIES AND HIGH-SUGAR GENES
corn varieties are available in white, yellow, or bicolor kernel
colors and in tall or short sizes. They also come in varying
maturities that are categorized as early (60-70 days) mid-season
70-80 days), or late season (90 or more days). Additionally,
you can choose varieties for their genetic heritage. These
are explained below.
Varieties. Old sweet
corn varieties such as Gold Bandam,
Early Gold Bantam,
and Country Gentleman are "open pollinated," meaning
that the seed was derivied from a natural polination process,
such as insects or (in the case of corn) wind, and that
it will breed true, or nearly so. (Open-pollinated varieties
change gradually as the years pass through natural or human
selection.) You can save and plant seed from these.
or Standard Varieties, or "Normals." The seeds of these modern F1 hybrids—including Silver
Queen, Golden Midget, and Early
Sunglow—are derived from a cross
between two other varieties; thus they are the first generation
(F1) after the cross. Hybrids have what is called hybrid
vigor. The provide the gardener with such characteristics
as high yields, disease and pest resistance, sweetness,
and dependable harvest.
or Supersweet Hybrids. This
gentic type (SH2), including such varieties as Illini
Extra Sweet, Early Extra Sweet and How
Sweet It Is, has sugar
content twice as high as that of standard sweet corn at
peak maturity. SH2 types are called supersweet, ultrasweet,
or extra sweet. The term SH2 stands for "shrunken 2" because
when the kernels dry, their seed coats shrink, giving the
seeds a shriveled appearance. Supersweet varieties retain
their sweet flavor longer than ordinary sweet corn both
on the stalk and after the harvest. But SH2 varieties must
be isolated from other types of sweet corn, or else foreign
pollen will make hard, ugly, dented kernels on the SH2
ear. (See above.)
Enhanced (SE) Hybrids. Varieties
in this class, including Kandy Korn, Early Glow, and Snow
Queen, are the result of a cross that produces a sweet
flavor and tender texture. This geneteic type (SE) contains
genetically high sugar levels, revolutionary in the flavor
of sweet corn. The seed coat of this type is not shrunken
like that of supersweet, so it sprouts more easily in the
ground. It is also much sweeter than regular sweet corn
and retains its flavor before and after harvest. SE hybrids
must be isolated from SH2 hybrids, but not from other SE
varieties or SU varieties.
RECIPE: MAKE YOUR OWN COMPOST TEA
There are a
variety of instructions available on how to create your own compost
tea brewer. Many involve purchasing and assembling the parts for aerating
the tea. Aeration helps accelerate the growth of beneficial (aerobic)
bacteria and will produce usable tea in 24 to 48 hours. However, if you
are willing to wait a few more days, you can get the same results with
a bucket, some string and a recycled vegetable bag from the market. Here
are the instructions/recipe for the most basic but effective method,
and your plants will love it:
- Save a perforated plastic or mesh bag from onions,
oranges or potatoes to use as a giant tea bag.
- Fill the bag with manure or homemade compost and
tightly tie the top closed with string, leaving 3 to 4 feet of string
- Place the filled bag in a 5-gallon bucket, allowing
the excess string to fall over the edge.
- Place the bucket in the shade and fill it to the
top with water.
- Cover the bucket loosely with a lid or with heavyweight
aluminum foil, wiht the string on top so it doesn't act as a siphon.
- Allow the contents of the bucket to ferment for
three days or longer. (The longer you leae it, the more fermented
and odiferous it will become, but also the more effective.)
- When aged to your satisfaction, mix 1 cup of the
dark brown concentrate with 2 gallons of water and p our over the
roots of plants. (On overcast days, also pour diluted solution ofer
plant leaves or use as a foliar spray.)
- After using up all the brown liquid, return the
contents of the "tea bag" to the compost pile.
- To perk up your plants for a special party or event,
apply manure or complst tea ten days prior.
Remember, corn can be planted in succession through
April, May and June. Happy planting!
by Robert Allan Williams
Sweet corn, sweet corn, so roasting hot,
I'll sing a merry tune if I may eat you up.
Sweet corn, sweet corn, warm in the pot,
I'll dance around the room and whistle through my cup.
Thanks to Pat Welch’s Southern
California Organic Gardening, from which comes much of my information.
‘til next time.
Vicki Rankin, Oak Park Community Garden