Growing Sweet Corn Successfully in the Family Garden

After tomatoes, sweet corn may be the most popular crop grown in many family gardens.

However, as popular as it is, growing corn presents some difficult choices, mostly having to do with what other crops you will have to leave out.

In the limited space of a family garden corn is a poor choice if you are trying to maximize your garden yield, because one corn stalk only produces one or two ears, while a vertically-grown tomato plant taking up the same space can produce 10 to 20 POUNDS of tomatoes. Even a cabbage plant can produce 2 or 3 pounds in 2/3rds the time most corn requires to mature.

You can maximize your production of corn by planting close together in two rows per bed, and planting several short parallel rows, rather than one long one, because corn is pollinated by the wind carrying pollen from the tassels to the silks, and most comes from neighboring plants.

Build your garden using 18”-wide level, slightly raised beds with 4”-high ridges, and plant seeds or transplant seedlings 8” apart in the row, with rows 12” apart in the bed. Plant at the base of the ridges, rather than on the ridges. And aisles should be 3’ wide.

Because corn is considered a TENDER crop planting should not be done until AFTER the average last Spring frost date. Using early varieties can improve that somewhat, but even earlier and better results can be achieved by growing seedlings in a protected environment and transplanting strong, healthy seedlings into the garden on the date you would otherwise plant your seeds.

Transplanting seedlings also assures that you have 100% crop coverage, further maximizing your yield. This can be a big factor to consider, as cold weather, too-wet soil, bugs, diseases, birds, and other pests can substantially reduce the percentage of seeds that survive to become healthy seedlings.

Do NOT try to use the seeds from hybrid corn you’ve grown, since hybrid seed will be different than the parent seed, and usually produces inferior plants and ears.

Hybrid varieties have been developed in recent years that give us our choice of white, bi-color, or yellow corn, and are very high in sugar content. And the double and triple-sweet varieties will retain their sugar for several days after picking, if they’re refrigerated.

Hybridization has also produced corn with different maturity times, as well as frost and heat tolerance. This means that some varieties can be planted fairly early in the spring to give a June/July crop, and others planted later will mature between August and October. Later varieties are usually sweeter.
To maintain the sweet quality of the corn you are planting, isolation is recommended to prevent cross-pollination with other types.

When isolating corn there are four things you can do, separately or in combination, to minimize cross-pollination. Farmers often first consider distance, then time. Other considerations include barrier rows and wind direction.

For the home gardener it’s more important to isolate by TIME rather than by physical distance, barriers, or avoiding wind.

TIME ISOLATION – The home gardener rarely has sufficient space to avoid cross-pollination of corn. It’s much easier to determine the days to maturity and then plant two to three weeks before or after, so the pollen from one variety is not in the air during the time silk from another variety is receptive.

Once pollen is released from the tassel it is viable for about 24 hours, so avoiding that time period is critical. And the tassels from one planting can continue producing pollen for up to two weeks, so a minimum of 14 days should separate the tasseling time of the different types.

DISTANCE – Plants that are 12 feet apart may have as much as 50% cross-pollination, and cross-pollination of 1% requires separation of anywhere from 50 to 660 feet, depending on whose studies you believe.

BARRIER ROWS – Much of the contaminating pollen can be diluted by planting several rows of a different vegetable between varieties of corn. For this to be really effective the rows must be tall and constitute a real barrier, such as pole beans, vertically-grown tomatoes, etc.

WIND DIRECTION – By not planting different varieties of corn down-wind from each other isolation can also be improved.

If you can’t wait the requisite two weeks between plantings, the other three factors can be used to limit cross-pollination as much as possible.

Corn should be picked while the liquid inside the kernels is milky. Waiting too long will result in the sugar turning to starch and a considerable loss in the sweet flavor. Refrigerate as soon as possible to slow the sugar’s conversion to starch.

Good Eating!

Avoiding Cross-Pollination of Different Varieties of Corn

Q. I want to grow some of the different colored corn. The seed package says to isolate. How far from the other corn does this have to be to avoid cross pollination?

A. When isolating corn there are four things you can do, separately or in combination, to minimize cross-pollination. Farmers often first consider distance, then time. Other considerations include barrier rows and wind direction.

For the home gardener it’s more important to isolate by TIME than by physical distance, barriers, or avoiding wind.

TIME ISOLATION – It’s very difficult for the home gardener to find sufficient space to avoid cross-pollination of corn. But it’s fairly easy to determine the days to maturity and then plant two to three weeks before or after, so the pollen from another variety is not in the air during the time your isolated variety is receptive.

Once pollen is released from the anther, which is in the tassel, it is viable for about 24 hours, so avoiding that time period is critical. And the plants from one planting can continue producing pollen for up to two weeks, so a minimum of 14 days should separate the tasseling time of the different types.

DISTANCE – According to a study by the University of California plants that are 12 feet apart will likely have 50% cross-pollination, and while pollen concentration is only 1% at a distance of 200 feet one study showed that cross-pollination of 1% required separation of 660 feet.

Other studies indicated 1% pollination occurred at distances of only 40 to 50 feet, but even that distance is difficult to maintain in the typical family garden.

BARRIER ROWS – A large percentage of contaminating pollen can be diluted by planting several rows of a different vegetable between different varieties of corn. For this to be really effective the barrier rows must be tall, such as pole beans, vertically-grown tomatoes, etc.

WIND DIRECTION – By not planting different varieties of corn down-wind from each other isolation can be improved, but not fully achieved.

If you can’t wait the requisite two weeks between plantings, the other three factors can be used to limit cross-pollination as much as possible.

Corn Sprouts – How Do I Keep Them Alive & Growing Healthy?

Q.  My corn seems to sprout alright, but for some reason I only end up with 1/3rd or 1/4th of the plants I expect.  What’s happening?

A.  Humans aren’t the only ones who enjoy sprouts.  larger birds, such as crows, will eat your corn just as it’s sprouting if given a chance. 

It may also have been that you had cold ground, though.  Corn likes warm soil, and will rot in the ground if it’s cold. 

In early spring, I recommend you plant your corn seed in the black plastic trays with 36 2″ pots, and grow it in the warm greenhouse.  Your seedlings must have full sunlight all day long,however – or growlights 16-18 hours each day.

You can grow it 3-4″ tall before transplanting.  try not to disturb the root ball, and water well after transplanting.  As with all transplants, apply 8 oz of 34-0-0 per 30′ soil-bed containing 2 rows of plants (which you probably can’t get anymore) or 12 oz of 21-0-0 before watering, and water in well – then 3 days later begin the Weekly Feed regimen.  Remember that you must give corn full sun, even in the greenhouse, or they will be pathetic and never recover fully.

Growing Corn in the Greenhouse – Possible and Practical?

Q.  Can I plant corn in a pot to start it and then replant it in the garden when it warms up, since it is still cold, or should I just wait and do it all outside?
 
A.  Corn is a tender plant and will be killed by any frost.  Also, it will not grow when the ground is cold.  So, it should not be planted in the garden until the danger of frost is past and the ground has warmed up somewhat. 
 
We have grown corn in the greenhouse successfully on several occasions, so it can definitely be done.  You can plant in pots (2″ – 6-paks are preferred), but don’t do it more than 3-4 weeks before planting into the garden because they will outgrow the pots, require transplanting, and take up even more space 
 
However, whether or not to plant under lights or in a greenhouse, and then transplant into the garden, should be decided based on other factors.
 
Any planting – and especially greenhouse production – should consider the value of the crop vs the cost and amount of work involved.  Planting 50 corn plants will yield 50+ ears of corn MOL, worth about $5.  Is it worth the time, cost, effort, and space in your growing facility, or are those scarce resources better used to grow something with more value to you?  The other end of the value curve may be tomatoes, let’s compare.  Fifty indeterminate tomato plants, grown vertically, will occupy only a little more space in your garden, but will yield 1,000-2,000 tomatoes worth $250-500. 
 
Unless there is substantial value to you in having the first fresh-from-the-garden home-grown corn in the community, you may decide to grow something else.

Lodging in Corn and Other Cereal Crops – Cause & Cure

Q.  Do you have any tips on how to keep corn from lodging?  I generally hill up the dirt about 4-5 inches when the plants are about 18 inches tall. It helps but the problem still persists if we get a big wind, especially if I have just watered.
 
A.  There are actually two problems included in his question. 
 
First, lodging is when corn stalks or other cereal grain stalks break easily.  This condition is caused by a deficiency in Potassium!  Feed your crop properly, using the Pre-Plant and Weekly Feed mixes, and you won’t have problems with lodging.
 
Second, if a crop suffers from weak stalks because of potassium deficiency, it will fall over and break when a strong wind blows.  However, corn, and to a lesser degree all the cereal grains, are susceptible to being hurt by strong winds – even if their stocks are strong.  This is because a tall stand of corn is almost solid, and catches the wind like a sail.
 
So, if a very strong wind blows across your rows of corn, it may very well bend them over, especially if it is shortly after you have watered, because watering softens the soil and allows the roots to be pulled out more easily (think of harvesting carrots immediately after watering).
 
When your corn has been knocked over by the wind, if it’s not too far – only 45 degrees or less – it may stand up again by itself in a few days. 
 
In back-yard gardens you can help it to stand up by watering, then lifting it up, placing baling twine against it about 3′ from the ground, and wrapping the baling twine around tall stakes you’ve driven into the ground at the peak of the ridges at intervals of every 3 or 4 feet. 
 
Even if you don’t get it straight up, giving it this much help will usually be enough for it to straighten up the rest of the way.  And be careful that you don’t pull the roots out of the soil in the process!
 
It’s important to get it standing again if you can, because when it bends over, the distribution of the pollen from the tassels to the silk is often substantially reduced, and your corn yield will be seriously affected.

I’ve discovered smut in my corn. Must I tear it all out? Can I plant again next year? Are there varieties that are resistant? What varieties are most susceptible?

Corn smut – a fungus disease called Ustilago maydis – is extremely common. It cannot be controlled with fungicides, nor with treating the seed. The spores can be carried into your garden by the wind, even from long distances. Plant infection often occurs through wounds. Therefore, avoid injury to roots, stalks and leaves while weeding. Insect damage can also leave the plant vulnerable, so eliminating corn worms, beetles, and earwigs may help.

No, you don’t need to tear everything out. Very rarely is a corn crop rendered unusable by smut. To minimize the damage, remove the immature galls before they break open – and eat, bury (away from the garden), or burn them.

Yes, it can safely be eaten! In Mexico, the immature smut galls are consumed as an edible delicacy known as cuitlacoche (wheat-lah-KOH-chay). Think mushrooms. Even in the USA, restaurants catering to Hispanic customers sometimes feature this item on their menus. Try them cooked with scrambled eggs.

Meanwhile, to reduce the problem of having them grow in your corn, remove the galls early, and if the infection is bad, do not plant corn in that area for 3-4 years. The white Sugary Enhancers are reported to have some resistance to common smut.