Growing Corn

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Some corn kernels don’t fill out at the tips of the corn ears

Sometimes the tips of the ears, or kernels even deep down in the ear, don’t fill out. That’s okay.

Sinking your teeth into a perfectly ripened ear of sweet corn is one of the finest pleasures of summer, and early-maturing sweet corn varieties like Sugar Buns will offer a harvest sooner than you might think. You will need to wait 3 weeks longer for Silver Queen, but your reward will be kernels packed with sweetness and rich corn flavor.

Corn needs plenty of space for two reasons — it is a heavy feeder, and it is primarily pollinated by wind. As grains of pollen are shed by the tassels that grow from the plants’ tops, they must find their way to the delicate strands of silk that emerge from newly formed ears. To make sure silks are nicely showered with pollen, grow corn in blocks of short rows rather than in a long, single row. In a small garden, 15 plants set 1 foot apart can be grown in a 3 x 5-foot bed. Growing corn on this tiny scale is a good way to introduce yourself to the crop if you’ve never grown it. After the first year you will probably want to increase the size of the planting to at least 4 rows 10 feet long.

Corn plants are not like tomatoes or most other vegetables, which bear over a long period of time. Instead, they form a few ears per stalk and they are finished. Because of this, gardeners who have the space often make 2 or 3 plantings 2 weeks apart to keep the harvest coming.

Soil, Planting, and Care

Corn planted in a garden with black groundcover to warm the soil

In areas where the soil stays cool longer, cover the ground with black plastic or IRT film a week or two before planting and set plants through holes cut into the material.

Corn needs a spot with that gets full sun and has fertile, well-drained soil with a pH of 6.0 to 6.8. Seedlings can be set out as soon as the last spring frost has passed. Space plants 8 to 12 inches apart. In case of a surprise late frost, be prepared to cover seedlings with a fabric row cover. In cold climates you can plant in a raised bed covered with black or IRT plastic (infrared transmitting plastic) that will warm the soil. If possible, lay the plastic a week or so before planting.

Plan to fertilize twice because corn is a hungry plant. Before setting out seedlings, amend the soil with compost and mix a balanced organic or timed-release fertilizer into the soil. About a cup of 10-10-10 per 10 feet of row is a good general rate, but be sure to check and follow rates given on the label of any fertilizer you are using. About 6 weeks or so later, when the plants start to produce tassels, fertilize them again. (If you amend the soil with cottonseed meal or other high-nitrogen amendment, it may not be necessary to feed the second time.) Use a hoe or trowel to mix the fertilizer into the top inch of soil between the plants. After this booster feeding, water your corn once or twice weekly if the weather is hot and dry.

Normal plants should grow fast with dark green healthy leaves. Corn will tell you if it is hungry by turning very light green. If so, feed again.

Corn grows fast and needs lots of water to grow properly. It also has shallow roots that make it susceptible to drought. Soaker hoses will insure that your corn gets the water it needs. However, for a large planting, soaker hoses may not be practical.

Hopi and Navaho Techniques
Native Americans in arid climates planted corn in basins to catch spring rainwater and help keep the corn roots down where water would be available longer. The basin was about 4 inches deep and 2 to 3 feet wide with a raised ridge made from the excavated soil around it. Plants were arranged so that they formed a spiral from the center to help with support in wind and with pollination. If you live in an arid climate or a hot climate and have poor sandy soil, as in the Coastal Plains, this technique could help ensure a good harvest.

Troubleshooting

Corn growing in a garden with other vegetables

Corn plants need plenty of space because they are large, but they can be planted with other vegetables in a large garden. Plant corn in blocks of rows at least 4 across so the wind can scatter their pollen to neighboring plants.

Corn plants that are blown over by gusty storms usually right themselves after a few days of sunny weather. As you shuck and clean your corn, pop off ear tips damaged by corn earworms. The different types of corn should not be allowed to cross-pollinate, so plant them in such a way that pollen from one type does not reach another type. If you or a nearby neighbor grow multiple types, be sure that they are isolated by at least 250 feet or that their timing is such that they are not in bloom at the same time. If not, the pollen from types that are not the same can muddy their characteristics to the point of ruining sweetness and flavor.

Raccoons love corn. The most effective way to keep them out of the patch is to surround it with a fence with 2 strands of electric wire 4 and 12 inches from the ground. Some gardeners have been successful with throwing blackbird netting over and around the plants because some raccoons don’t like it. The methods for keeping raccoons out of corn are as varied as gardeners themselves. We’ve heard of people putting flashing lights in the corn patch, putting a radio on a timer to blare loud music, laying newspaper in rows because the raccoons don’t like to walk on the crinkly paper, spraying animal repellents, and other techniques, but a physical barrier such as an electrified fence seems to be the most reliable.

Harvest and Storage

Know when to harvest corn from the garden by looking at the silks. Brown silks mean the corn is ready.

Corn is ready to harvest when the silks are brown and the ear is filled out. Peel back the tip of the ear to check the sap.

Most corn plants will yield at least 2 ears per stalk. Hybrids may yield more. To see if an ear is ready for harvest, look at the silks. They should be brown and dry with just a little fresh green at the base. Squeeze the husk to see if the ear inside feels plump, not skinny. If you’re still not sure if the ear seems ripe, check by peeling just enough of the husk back to expose a couple of inches of the ear. Poke a kernel with your fingernail. The corn is ready to pick if it bleeds a light milky sap like skim milk. If the liquid is clear, the ear is not ready. Ears that are too ripe will look too milky, like cream versus skim milk; they often taste starchy. Remove them right away.

Perfectly ripened ears also taste sugary-sweet when sampled raw. When possible, harvest sweet corn in the morning, when the ears are cool. To remove the ear, use one hand to hold the corn stalk and the other to pull the ear down and away from the stalk, twisting a little until it breaks off.

Place harvested ears in the refrigerator right away. When kept chilled, they should hold much of their sweet flavor for up to a week, though they’ll taste best if eaten as close to harvesting as possible. Corn can be blanched and frozen, on or off the cob.

FAQs

What are the reddish spots showing up on my corn leaves?

This disease is called rust and cannot be controlled. Typically, rust won’t damage corn yields, unless growing conditions are exceedingly stressful (drought, flood, etc.).

When is the best time of day to harvest corn?

Sweet corn is ready to pick when a test kernel pierced with your fingernail bleeds a light milky sap, like skim milk. Ripe ears will taste sugary-sweet when sampled raw. After picking, the sugar in corn turns to starch, reducing sweetness. Knowing this, some people harvest corn right before cooking, thinking they’re preserving the sweetness. Corn actually has the highest sugar content early in the morning, before the sun touches them. If you want the sweetest flavor, pick ears early in the morning and refrigerate in the husk until cooking.

How do I know if ears are ripe?

Try to avoid peeling the husk to peek at ears. It’s best to keep husks in place until cooking. Ripe ears feel full and rounded and have silk that’s dried and brown on the ends. If you do peek at end kernels, pierce a kernel and look for milky sapÑthat’s another sign of ripeness.

I was weeding around the corn with a hoe yesterday. Today stalks are wilted, even though the soil is moist. What is happening?

Corn is a shallow rooted plant. You might have broken corn roots if you hoed weeds deeply, chopping into soil near stalks. Keep weeds in check by cultivating frequently so you don’t have to do much more than scuffle the soil to dislodge offenders.

The corn in my garden is attracting birds and raccoons. What can I do to protect the harvest?

A scarecrow can keep birds at bay if you dress it in loose fitting clothes that will move in the wind and decorate it with strips of aluminum foil to flutter and reflect light. Ideally, move your scarecrow every few days so birds don’t become accustomed to it. Raccoons require more aggressive tactics. Try a two-strand electric fence (one strand 4 inches off the ground, the second strand 12 inches high). Turn on the power about a week before you think the first ears will be ripe.

Shoots are coming out of my corn stalks near the ground. Will they produce corn?

These shoots are called suckers and won’t form ears. While it’s not necessary to remove them, many experienced home gardeners believe removing suckers produces larger, better quality ears. This hasn’t been proven. If you do choose to remove suckers, snap them off while they’re less than 3 inches tall to avoid damaging the stalk.

My garden space is small. Can I grow corn without planting it in long rows?

Corn is wind pollinated, and research has proven that it’s actually better to arrange plants in blocks of short rows rather than long rows. That means even small gardens can squeeze in a corn crop. Arrange corn in at least four rows side-by-side, spacing rows 12-24 inches apart. Wind will blow the pollen from one corn stalk to another.

34 thoughts on “Growing Corn

  1. my wife planted my corn while I was tilling my garden. I found out afterwards she planted them 3 to 4 inches apart. Will they be okay leaving them that close? What should I do….if anything?

    • Hi Jason,
      Corn does grow better when it is spaced about a foot apart. It is a heavy feeder for one – requires a lot of nitrogen since it is a grass. You could thin it to allow for more space. I would not try to transplant the corn. If you want to leave it and see what happens – you can always plant more :) Your own experiment. -danielle, Bonnie Plants

  2. I have a small garden and my 8 corn plants have corn rust. Should I pull up my corn or let it keep growing?

    • Hi Jen,
      Rust is a common fungus in cool, humid environments. It is rarely a cause for serious concern. Read more about corn rust here from Clemson Univeristy Extension. -danielle, Bonnie Plants

  3. Can you plant different types of corn near each other, I have Silver Queen and Bi Liscious Hybrid and was not sure if I could do rows next to each other or not

    • Hi Sue,
      When you plant your corn, try planting it in smaller blocks rather than long rows. Since corn is wind pollinated, planting in blocks helps fill out the cobs!
      Crosspollination can occur by wind-blown pollen between the two types of corn. This means you may have some odd colored ears – some yellow kernels in your white ears. If you plant super sweet corns and they are pollinted by other sweet corns, they may not be as sweet as they usually are.
      – Danielle, Bonnie Plants

  4. I am planning to plant silver queen seedlings in a moveable container so as to seek sun and avoid persistent wind. I installed a plastic mesh chicken wire around the container to keep my cats out. They love to eat corn seedlings! My question is this the seedling packs have as many as three seemingly viable plants in some of the partitions. I inspected the roots and they are all intertwined. Should I cut the smaller of the multiple seedlings to plant only one plant at a time?

    • Hi Martha,
      I would plant the individual partitions as is. Pick the strongest seedling and cut away the others. Corny cats :)
      -Danielle, Bonnie Plants

  5. I’m in the ‘Old Cross Forest’ of East Central Oklahoma. Critters are a major problem here, everything from poisonous snakes, bear, deer, racoons, possum, beaver, skunk, armadillo, squirrel, gopher, moles, grasshoppers, to hawks and eagles.
    I’ve just constructed an 8′ x 8′ open extension on the back of my greenhouse for corn, beans, and potatoes that I’m covering with 1″ mesh chicken wire over a 2.5′ x 18″ grid of 1″ PVC pipe, all tied to the grid, completely enclosed with a door for access. It’s a peaked top 8.5′ high at the peak, with sides 5.5′ high. It’s partially under a hundred+ years old 60′ Black Oak that I’m trying to find a service to remove. Being right off Lake Eufaula, the soil is very sandy below the top couple of inches of old leaf compost, so drainage shouldn’t be a problem, and I’m adding a composted manure to about 6″ depth. Beans will be along the sides, with corn in an elongated basin on one side, (my wife is Navajo/Chiricahua) and the potatoes on the other side in 2 rows.
    Does it sound like this is all going to work?

    Got strawberries, broccoli, cauliflower, tomatoes, lettuce, and asparagus already producing inside the greenhouse, garlic, onions, basil, and cucumber in an adjacent fenced open garden. Hopefully the sunflower patches I started around it will deter the birds and squirrels.
    Going to start brussel sprout seedlings in late summer, and a few other things as weather permits.

    • Wow Larry,
      You have a lot of competition in your garden! I would be leary about trying to grow veggies within the shade of the tree canopy. You may think about waiting until the tree is removed before you get the garden spot ready. All gardeners have different pests that have to deal with, fencing in the area is great idea. -Danielle, Bonnie Plants

  6. How can i stop the possums, squirrels and racoons from eating my corns ? they ate everyone last summer i live in Queens NY

    • Hi Carrol,
      Oh no. These are very opportunistic animals. The Cornell Cooperative Extension System has a publication on wildllife damage management. A two wire fence around the garden is suggested as well as filament tape on the corn.
      Happy Gardening,
      Danielle

    • A stay at home outdoor cat & some type of small aggressive outdoor dog posted 24/7 in the garden .. bada bing bada boom :-)

      • I agree with you! An outdoor cat can do wonders when it comes to varmint control.-
        Danielle, Bonnie Plants

      • We’ve got a very aggressive outdoor cat and dog. Problem is….we bring them both in shortly after noon so they’ll be safe from the bears, racoons, and bobcats. The dog likes to hang out at the lake when she’s out so doesn’t help much, and the cat prowls around for an hour or so, then gets up in one of the trees and just sits there watching the squirrels!
        The dog has brought home dead squirrels, racoons, beaver, armadillo, skunk, and parts of deer, fish, and several types of birds, but never seems to eat any.
        I’m always on the lookout for the snakes in warm weather, and have caught and killed many pigmy rattlers, copperheads, and a 5-1/2 foot water moccasin in the yard or under our decks.
        So far, looks like the 1″ mesh fencing that I’ve completely wrapped the greenhouse open extension with is keeping the squirrels out of the corn, beans, and peas growing in there. Expecting potatoes to break the surface within the next few days.
        Already have a few near golf ball sized tomatoes on last years plants, and quite a few marble sized strawberries on those. Cauliflower and broccoli have set heads, and asparagus are doing great, as is the garlic, chives, and onions. 3 varieties of lettuce inside the greenhouse doing well, and new seed starts are in progress for an on-going harvest season.
        All of this is from Heirloom seeds, except the potatoes and garlic.
        Now, if I can just get a break this summer from last summer’s 100 degree plus 3-1/2 month hot spell…………!

    • I have found that garilic will keep small animals away. Just watch it if they start to sprout and grow that is fine just break them in half and let them dry out.

  7. hi im doing a paper on produce development im wanting to know what are 5 desease that effect the corn growing process

    • Hi Jay,
      Good luck with the research on your paper. You’ll need your spell check for this one. A few of the diseases to watch for are listed by category. Corn smut, rust, fungal diseases: Pythium, Fusarium, Diplodia, and Penicillium; viral diseases: Maize dwarf mosaic virus (MDMV) and Maize chlorotic dwarf virus (MCDV), and several other diseases listed on this link from the Clemson Cooperative Extension Service. Definitely use your local Extension office for more information and photography. ~Mary Beth, Bonnie Plants

    • Hi Bruce, Yes, you should be able to pick them one at a time when they’re ready. Be sure to read above in the Harvest & Storage tab for tips on how and when to harvest corn. Happy harvesting! Kelly, Bonnie Plants

  8. Why do my corn stalks have red spots and streaks of red on them? The red spot appeared as the born of the stalks and now are showing up higher on the stalk, near the wars. I’m now also seeing baby size ants. I’m growing the Silver Queen corn in a raised bed…4×12 in size.

  9. Hello
    This is my first year of planting corn. I planted golden bantum. The plant is not suppose to be hybrid but it grew multiple stalks off off the main shoot. I don’t know if this is freak corn or what. This evening I just pulled off my first 2 ears. I don’t know if I picked them to early or not. I pulled part of the husk away and pierced one of the kernerls and it was milky. So I braught it is and husked the corn. Well it looks like there are alot of kernels that were still forming. The were a bunch that were huge but alot looked un-developed. This plant has about 10 cobs on it. Where ever one forms another one forms right from the base of that one.I baught the seeds from one of those survival seed vault things and it said it was was no gmao or hybrid. I have a few pics of the corn I husked and the plant itself. I wanted your opinion. Did I harvest too soon or was the corn ripe and not all pollinated. I’m ex- army special operations not a farmer. Hunting, fishing, and trapping I am awesome at. Living off the land we were trained in but not the actual farming part so this is new to me. I have never given up in my life and I don’t want to start now. Or should I just should stick to tomatoes and beans???.I did fine with that stuff….if I can send you pics and get your opinion it would be greatly appreciated…..thanks for your time
    Frank

    • Hi Frank, Don’t give up! I don’t know the answer but our expert at our Ask an Expert service will. You can submit your question with a photo for the best answer. Submit here: http://bonnieplants.com/ask-an-expert/. I hope this helps, and happy growing! Kelly, Bonnie Plants

  10. I planted 5 corn plants in a row about one foot apart. They grew real fast and were real dark green. But all of a sudden came gobs of little black ants. The ants wern’t so bad but they started to bring little black bug that I think we’re aphids. The ants created small black patches of the bugs all over the leaves and stalks. At first I tried hoseing them off. This worked pretty good but the next day they were back with vengeance. This went on for a few days. In the mean time I try to kill the ants. I tried boric acid to no avail on the ants. Bought several different brands of bat traps, but this didn’t work either. After a while the leaves browned, the corn wasn’t well developed and very small. What could of should I have done?
    Larry

    • Hi Larry,

      Sorry about your corn plants! Those black bugs sound like aphids and the ants probably came in after them to feed on the honeydew aphids create. Here’s a link from the University of Arkansas Cooperative Extension Service that discusses insects in corn and their control:
      http://www.uaex.edu/Other_Areas/publications/PDF/FSA-7021.pdf. I hope this helps you for next year!

      Kelly, Bonnie Plants

  11. why can’t soaker hoses be modified to irrigate our crop land and end the effects of the drought?

    • Hi Ron,
      I’m sure there are a million answers and ideas for this seemingly-simple question. One thing to remember is that drought conditions are not merely lack of rain; oftentimes the extreme heat and temperature highs affect pollination, stunt growth and retard production. Many farmers do indeed use drip irrigation, which is an even better conservation of water than a soaker hose. If you are interested in learning more about this, become a part of the U.S. Dept of Agriculture’s conversations online. Thanks for writing! Mary Beth, Bonnie Plants

  12. the kernel on the cob is not full to the top. I did fertilze twice useing -12-12-12

    • Hi Roy,

      This is a common complaint that can be caused by various growing conditions, from dry weather to planting too close to lack of potassium or poor natural pollination. Be sure to keep plants watered well, plant at recommended spacing (not too close), fertilize, and plant in blocks for more complete pollination. Your corn is fine to eat and enjoy, though, as it is. Happy growing!

      Kelly, Bonnie Plants

  13. My silver queen corn is very tall but ears are skinny this year. Could this be lack of sun. It gets only 6 to 7 hours sun where its planted. Ears are long but skinnier. Can you tell me any info. Thanks. Steve

    • Hi Steve,

      Thin ears or poor kernel development can be caused by a variety of factors: dry weather during silking, planting too close, poor fertility, or too few rows in a block resulting in poor pollination. Do any of these sound possible for your garden? Remember that corn plants need lots of water and fertilizer. You might need to increase both to increase the size of your harvest. I hope this helps!

      Kelly, Bonnie Plants

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