Corn is a tender, warm-weather crop. Sweet corn is commonly grown in gardens.
- Sow corn in the garden 1 week after the last frost when the soil temperature has warmed to at least 65°F (18°C).
- Start corn indoors 4 weeks before transplanting to the garden. Seedlings as small as 1 inch (2.5 cm) can withstand transplanting.
- Succession plant corn 1 to 2 weeks apart to extend the harvest. Time the last sowing so that harvest comes a week or two before the first expected frost in fall.
- Planting corn in cold soil or chilly weather risks poor stands and poor yield.
- Corn matures 60 to 100 frost-free days after sowing.
- Corn Sowing and Planting Tips
- Corn Planting Calendar
- Recommended Corn Varieties
- Growing Guidelines
- Hand Pollinating Corn
- Tips For Growing Corn Indoors
- Planting Corn Indoors
- Starting Corn Indoors Can Extend the Growing Season and Raise Productivity
- Starting Seeds Indoors
- Know Where to Start
- What You Need to Start Seeds Indoors
- Sowing Seeds
- Nurturing Seeds Indoors
- Learn More About Starting Seeds Indoors
- Additional Resources
- Choosing Containers to Grow Corn in Pots
- Varieties for Growing Corn in Containers
- Growing Corn in Alaska
- Growing corn in Alaska is a labor of love, says Carol.
- Start By Growing Your Corn Indoors
- Choose Your Corn Varieties Wisely
- Give Yourself Enough Space For the Corn To Grow
- Growing Corn In Alaska: Sweeter by Far
Corn Sowing and Planting Tips
- Grow corn from seeds or seedlings.
- Seed is viable for 2 years.
- Direct sow corn in the garden in spring after all danger of frost has passed and the soil has warmed to 60°F (16°C).
- Optimal soil temperature for growing corn is 65°F to 75°F (18-24°C). Corn will not germinate in soil chillier than 50°F (10°C).
- To start plants indoors, sow seed in peat pots 4 to 3 weeks before planting out. The optimal indoor temperature should be 70°F (21°C) until germination.
- Sow seed 1 inch (2.5 cm) deep.
- Seeds germinate in 4 to 10 days.
- Transplant corn into the garden after the soil has warmed to at least 70°F (21°C).
- Space corn 12 inches (30 cm) apart in all directions; plant corn in blocks of at least 4 rows for optimal pollination. About 4 plants for each square foot.
- Keep the soil just moist; letting the soil dry out will interrupt pod development.
- Fertilize with fish emulsion or a soluble complete fertilizer at half strength.
- Add aged compost to planting beds in advance of transplanting.
- Corn prefers a soil pH range of 6.0 to 7.0.
- Grow corn in full sun for best yield.
- Common corn pest enemies include aphids, armyworms, corn earworms, corn maggots, corn rootworms, cucumber beetles, flea beetles, Japanese beetles, leafhoppers, seed corn maggots, birds, and raccoons.
- Common diseases include bacterial blight, mosaic virus, rust, corn smut, southern corn leaf blight, and Stewart’s wilt.
Interplanting: Plant corn with bush beans, beets, cabbage, cantaloupe, cucumbers, melon, potatoes, pumpkins, and squash.
Container Growing Corn: Corn may not be a good choice for containers unless you have large containers that can hold multiple plants (to insure pollination). Choose a container 21 inches (53 cm) wide and 8 inches (20 cm) deep; plant at least 3 plants per container.
Corn Planting Calendar
- 4-3 weeks before transplanting seedlings to the garden: start seed indoors.
- 1 week before the last frost in spring: direct sow seed in the garden; protect seedlings from the chill with a row cover; minimum soil temperature should be 50°
- 2-3 weeks after the last frost in spring sow directly in the garden without protection.
- Every 2 weeks sow succession crops for a continuous harvest.
Sow corn in the garden 1 week after the last frost when the soil temperature has warmed to at least 65°F (18°C). Start corn indoors 4 weeks before transplanting to the garden.
Recommended Corn Varieties
- Early planting sweet corn varieties include ‘Early Sunglow’ and ‘Polar Vee’; midseason varieties include ‘Golden Bantam’ and ‘Honey and Cream’.
- Late-season varieties include ‘Country Gentleman’ and ‘Silver Queen’.
- For small gardens try ‘Golden Midget’ and ‘Tom Thumb’.
Botanical Name: Zea mays var. rugosa
Corn is a member of the Poaceae or grass family.
More tips: How to Grow Corn.
Corn is more American than apple pie and it’s been cultivated in North American gardens for over 4,000 years. Even though it takes up a large share of garden space, many gardeners make room because of the unbeatable sweet taste of fresh-picked ears.
The sugar in the kernels of ears of open-pollinated sweet corn varieties starts changing to starch almost as soon as you pick the ears. However, plant breeders have developed dozens of new and ever-sweeter cultivars that retain their sugar content for days. If sweetness is your prime goal, choose varieties listed as supersweet (abbreviated as sh2 in seed catalogs), but keep in mind that these may not be as vigorous as other types of sweet corn. If you prefer good old-fashioned corny flavor, pick standard (su) varieties. For a compromise between sweetness and vigor, choose sugary-enhanced varieties (se). If you like to experiment with the latest innovations, try planting a synergistic variety. These varieties produce ears with a combination of sugary-enhanced kernels and supersweet kernels on each ear. Whichever type you decide to grow, it’s a good idea to check with other local growers or your Cooperative Extension service to see what varieties have a good track record in your area.
If you have lots of garden space, you may also want to try growing some popcorn or ornamental corn, which have similar planting and care needs as sweet corn.
Corn is very susceptible to frosts. Look out for signs of frost to know if a cold snap will kill your crop. Corn doesn’t transplant well, either, so if you garden in a short-season area and want to start corn indoors, use biodegradable pots to avoid disturbing the roots at transplanting time. It’s better to wait until all danger of frost is past and the soil warms up to the 60 degrees needed for seed germination. If the weather stays cool, spread black plastic on the planting area to warm the soil more quickly.
If you want corn only for fresh eating, plant a minimum of 10 to 15 plants per person. To extend your harvest, sow an early-maturing type every 2 weeks for 6 weeks, or plant early, mid-season, and late types at the same time. To avoid cross-pollination, keep different corn cultivars (especially supersweets) 400 or more yards apart, or plant them so they tassel 2 weeks apart.
Site your corn patch in a sunny, wind-protected area. Corn is an extremely heavy feeder, especially on nitrogen, so it thrives in a place where soil-enriching crops like beans, hairy vetch, or clover grew the previous season, or add 20 to 30 pounds from the compost pile per 100 square feet to the soil as you prepare it for planting.
The best way to promote complete pollination is to plant corn in blocks rather than long individual rows — a block should be at least three rows wide. If you plant only one or two rows, hand pollinate to improve kernel formation.
For early plantings, sow seeds only 1 inch deep; in the hot weather of midsummer, plant them up to 2 inches deep. The average germination rate for sweet corn is about 75 percent, so plant three seeds together every 7 to 15 inches. They should germinate in 7 to 10 days. Thin to one plant every 15 inches. To avoid disturbing remaining plants, remove unwanted seedlings by cutting them off at soil level.
Corn can’t compete with weeds, so be sure to kill weeds thoroughly around the stalks for the first month of growth. After that, corn’s shallow roots will spread out as much as 1 foot from the stalk; be careful not to disturb these roots, because it’s easy to damage them. Instead, apply mulch to prevent weeds from sprouting.
Corn needs about 1 inch of water a week, particularly when the stalks begin to tassel. Water stress during pollination will result in ears with lots of missing kernels, so don’t skip watering your corn patch. Apply water at the soil surface by using a soaker hose or drip irrigation. Avoid spraying plants from above, which could wash pollen off the flowering tops.
When the stalks are 6 inches tall, side-dress them with blood meal or diluted fish-based fertilizer and repeat the feeding when they are about knee-high. Don’t remove any side shoots or suckers that appear; they won’t harm production, and cutting them might damage roots.
Cutworms sometimes attack corn seedlings and flea beetles may chew holes in the leaves of young plants.
Corn earworms are one of the best-known corn pests. They also attack tomatoes and are most prevalent in the southern and central states. Earworm moths lay eggs on corn silks and the larvae crawl inside the husks to feed at the tips of the developing ears. The yellow-headed worms grow up to about 2 inches long and have yellow, green, or brown stripes on their bodies. To prevent earworm problems, use an eyedropper or spray bottle to apply a mixture of vegetable oil, Bt (Bacillus thuringiensis), water, and a few drops of dishwashing liquid to the tip of each ear several days after the silks emerge. Or you can try pinning a clothespin to the tip of each ear once the silks start to turn brown to prevent the worms from crawling through to the ear.
European corn borers are 1 inch long, flesh-colored worms marked with tiny black dots that feed on foliage, especially near the top of the stalk where the leaves emerge. They also bore into the developing ears. Bt and spinosad are effective controls if applied early, before the borers tunnel into the stalks. Corn borers overwinter as full-grown larvae in weed stems and old cornstalks. Pull up and destroy such winter refuges to break their life cycle.
Cucumber beetle larvae, also known as corn rootworms, feed on corn roots, causing plants to weaken and collapse. Adults are yellow beetles with black stripes or spots. To kill the rootworms, apply Heterorhabditis nematodes to the soil.
Seed-corn maggots attack kernels planted too deeply in cool soil. These yellowish white maggots are ¼ inch long, with pointed heads. If they attack, wait until warmer weather to plant another crop at a shallower level.
Animal pests can seriously reduce your corn yields. Birds may be a problem at both seeding and harvesting time, while raccoons are fond of the ripening ears.
Clean garden practices, crop rotation, and planting resistant hybrids are the best defenses against most diseases, including Stewart’s wilt, a bacterial disease that causes wilting and pale streaks on leaves.
Corn smut makes pale, shining, swollen galls that burst and release powdery black spores. Cut off and dispose of galls before they open. If necessary, destroy affected plants to keep smut from spreading. It can remain viable in the soil for 5 to 7 years.
Hand Pollinating Corn
In order to produce kernels, wind must deposit pollen from the tassels (plant tops) onto each of the silks on the ears. Every unpollinated silk results in an undeveloped kernel. If you’re planting only a single or double row of corn plants, you can improve pollination by transferring pollen from tassels to silks yourself. Collect pollen as soon as the silks emerge from the ears and the tassels have a loose, open appearance. Wait for a morning when there’s no breeze, and shake the tassels over a dry bucket or other container to release the pollen. Collect pollen from several plants. Immediately transfer the pollen into a small paper bag and sprinkle the powdery material onto the silks of each ear in your corn patch. Repeat once or twice on subsequent days for best results.
Three weeks after corn silks appear, start checking ears for peak ripeness. Pull back part of the husk and pierce a kernel with your thumbnail. If a milky liquid spurts out, the ears are at prime ripeness — rush those ears to the table, refrigerator, or freezer. Ears on the same stalk usually ripen a few days apart. A completely dry silk or a yellow or faded-green sheath means the ear is past its prime.
Leave ornamental corn and popcorn on the stalks to dry until the first hard frost. If the weather is cloudy and wet, cut and stack stalks in a cool, dry place until the corn dries.
Tips For Growing Corn Indoors
For people who live in apartments or simply need an escape from the winter blahs, the idea of growing corn indoors may seem intriguing. This golden grain has become a staple of the American diet and is as much a part of our rural landscape as cows and tractors. But, to grow corn indoors, you have to be dedicated. Growing corn in containers in your home is not impossible, but can be difficult. Let’s look at what it takes to start indoor corn growing.
Planting Corn Indoors
Start with corn seed. If you are growing corn indoors, it’s probably a good idea to plant a dwarf variety of corn such as:
- Miniature Hybrid
- Golden Midget
- Early Sunglow
When indoor corn growing, the corn plants will be relying entirely on you for nutrients. Add plenty of composted manure or fertilizer to the soil for growing corn in containers. Corn is a heavy feeder and will need it to grow well.
Corn seedlings don’t transplant well, so if you are growing corn in containers, just plant the seed straight into the container you’ll be growing the corn. The container you choose should have ample room for four to five full size corn stalks. Use a wash tub or other large container for planting corn indoors.
Plant the corn seed 4 – 5 inches apart about 1 inch deep.
Once you get the corn seed planted, place the corn in plenty of light. This can be difficult when you grow corn indoors, as the available sunlight won’t be enough. You’ll need to supplement the light. Add grow lights or fluorescent lights to the area where you’ll be growing corn indoors. The lights should be as close to the corn as possible. The more artificial “sunlight” you can add, the better the corn will perform.
Check plants weekly. Water the corn as needed — whenever the top of the soil is dry to the touch. When planting corn indoors, the corn will typically need less water than corn planted outdoors. Keep a careful eye on not overwatering when growing corn in containers; too much water may cause root rot and will kill the plants.
As we said, growing corn indoors is no easy task. To grow corn indoors, make sure that you have created the right condition for the corn to grow well. Once you have done this, planting corn indoors can be fun and rewarding.
These big plants will grow in almost any soil, but getting the cob to mature is another matter. The maturity of the ears (cobs) is not controlled by the size of the plant, nor by day-length, but by the accumulated heat the plant has had while it grew. They call this the “heat units”. Only temperatures above 50 F count after the last killing frost of spring. Temperatures above 50 F add up to create the heat units. Corn plants generally grow very tall, and will shade other vegetables. Some plants will benefit from this shade, such as lettuce, but heat-loving plants must be placed so that the corn does not shade them. This heavy-feeding plant also provides a stalk for plants such as Pole Beans. Follow along with this handy How to Grow Corn from seeds Guide and grow food.
We Recommend: Honey Select (CN363). This so-called Triple-sweet hybrid was bred with the home gardener in mind. Plants are tall and productive, and don’t require complete isolation from other corn varieties the way most do.
Season & Zone
Season: Warm season
Zone: 4 to 8 – dependent more on summer heat than zone.
Plant between May 15th and June 10th. If the soil is not warm enough, seeds often rot before sprouting – especially when not treated with fungicide. Untreated corn seeds should be planted only when the soil has warmed up above 18°C (65°F) – warmer for super-sweet (sh2) types, and even warmer for a good stand. Use a soil thermometer. If spring weather is cold, consider planting in flats indoors with bottom heat for transplanting. Seeds should germinate in 7-10 days. If it rains after planting and corn does not emerge, just replant the area.
Ideal pH: 5.8-6.8. Corn is a heavy feeder, so add manure or compost, and use 500g (1 lb) of complete organic fertilizer per 6m (60′) of row, mixing it thoroughly into the soil beneath each seed furrow. Thin to at least 20-25cm (8-10″) apart in the row. Large eared and double-eared varieties need to be 30cm (24″) apart. Keep free of weeds until knee-high, and then leave it alone. Use the days to maturity listed for comparative purposes among the varieties only – your garden may be different.
When the silks at the top of an ear are a dry brown, the cob seems to start to droop and the kernels release milky juice when cut.
Leave the ears of popcorn varieties on the plants to dry as long as possible into late summer and early fall. The husks should turn yellow/brown as they dry and the kernels should harden. Once the plants appear to be completely dry, or if wet weather is in the forecast, harvest the ears and bring them indoors. Remove the husks. Store the ears in mesh bags in a warm, dry, airy location. The ideal humidity level for curing popcorn is 13 to 14%. Curing is the process after drying that allows for long term storage of popcorn kernels. Once a week, remove a few kernels and try popping them. Popcorn that is chewy or kernels that have jagged edges after popping both mean that the kernels are not dry enough. Continue curing and test-popping until the desired texture is reached. Then remove the kernels and store them in an air-tight container.
In optimal conditions at least 75% of seeds will germinate. Usual seed life: 2 years. Per 100′ row: 400 seeds, per acre: 87M seeds.
Diseases & Pests
Disease: Prevent disease and nutritional exhaustion of the soil by using 4-year crop rotation and composting old stalks.
Pests: Wireworms are a bad pest in home gardens. Loopers are pale olive-green caterpillars up to 2.5cm (1″) long. They chew into the centre of young corn plants and can kill the plant if the growing tip is damaged. Seed corn maggot is a small, legless maggot that attacks germinating seed. Planting in warm soil or using predatory nematodes may help prevent seed-destroying soil creatures.
Corn is a good companion to beans, beets, cucumber, dill, melons, parsley, peas, potato, soya beans, squash, and sunflower. Avoid planting next to celery or tomatoes. Amaranth makes a great mulch between rows by competing with weeds and conserving ground moisture.
More on Companion Planting.
Starting Corn Indoors Can Extend the Growing Season and Raise Productivity
I’ve discovered three things that are essential for such a high success rate. The tubes must be held closely together from the start. Soil must fill any gap spaces between tubes. It’s best to start the corn no earlier than three weeks before transplant date.
I have left the corn in their tubes and also removed them upon transplantation—both of these methods have yielded the same success rate as long as I make sure to bury the entire tube if keeping them intact. Interestingly, the tubes wick moisture out of the soil. For this reason, it’s important to carefully monitor moisture while indoors and to completely cover the top of the tube when planting the seedlings outdoors. The tubes will decompose by the end of the season and are well on their way by just a few weeks in the ground.
As you can see in the photo above, the corn has no problem sending its roots right through the thin cardboard. With a bit of care, the roots that have gone wandering in the bottom of the larger container can be kept intact. Even if they break off, there are plenty of other roots to maintain the health of the plant.
Most of the corn I grow now is for dry use rather than eating off the cob. Since I have my nifty Wondermill for grinding the perfect corn flour and meal, I went a little overboard with corn babies this season. Until I added this appliance to my pantry, I had a dickens of a time grinding my corn. Now, it’s a whiz! I have 180 happy little plants—five different varieties—in various parts of the garden. Most of my corn beds have at least one squash family member keeping them company with beans nearby to round out the three sisters of Native American Indian practice (corn, squash, and beans).
I have no doubt that this year’s harvest will yield an abundance of new recipes. My mind has already begun to muse on the possibilities, and my fingers are itching to wander the Internet for inspiration. I’m thinking there may be more than the usual delicious cornbread to warm our hearts, souls, and tummies come Fall and Winter.
Photos by Blythe Pelham
Blythe Pelham is an artist that aims to enable others to find their grounding through energy work. She is in the midst of writing a cookbook and will occasionally share bits in her blogging here. She writes, gardens and cooks in Ohio. Find her online at Humings and Being Blythe, and read all of her MOTHER EARTH NEWS posts here.
All MOTHER EARTH NEWS community bloggers have agreed to follow our Blogging Guidelines, and they are responsible for the accuracy of their posts. To learn more about the author of this post, click on their byline link at the top of the page.
Starting Seeds Indoors
Get ahead on your gardening by starting seeds indoors and producing your own transplants. With a little planning, a few supplies and tools, plus some know-how, you’ll be on your way to seed starting success
Starting seeds indoors has many benefits, including an earlier harvest. While some crops can be direct seeded, you can start them indoors and move up the harvest date. Another perk of starting seeds indoors is the ability to grow long season crops in short season climates. If you have to wait for outdoor soil to reach the optimal temperature, you’ll miss out on growing days. But by starting seeds indoors and transplanting them when the time is right, they’ll have a head start on growing.
Know Where to Start
A little planning makes seed starting more efficient and will help set you up for success. Almost every seed can be started indoors, but people typically start long season crops, like eggplants, okra, tomatoes, broccoli and kale, indoors. Some plants do not fare well as transplanted or need to be transplanted at the right stage of growth so they aren’t stunted by stressors. Peas, beans, radishes, carrots, and corn perform best when they are direct seeded, straight into the garden.
Consider how much space you have indoors to house your started seeds and how you will nurture the seeds as they grow indoors. Keep your outdoor space in mind, too. You’ll want to have enough transplants to adequately fill your garden plot. Take a few minutes to sketch out your garden and determine where you’ll plant each crop of transplants.
Once you know how many transplants you’ll need, you can determine how many seeds to purchase and plant. It’s also smart to add a few extra seeds to account for things like seedling mortality.
Research is also key during the planning phase. Seed packets often have guidelines about when to start seeds indoors, germination information, days to maturity, and other growing tips. But know that recommended seeding and start dates are just that: guidelines. Understand your local climate nuances (for example, a history of late, surprise frosts) and adjust as needed.
What You Need to Start Seeds Indoors
The right tools and supplies are also important for seed starting. Early plant nutrition is vital and the right potting mix/media will provide the right nutrients. Your seedlings will spend their first crucial weeks in their starting cells and they will need additional nutrition from compost or liquid fertilizer. Plants are like humans – if they don’t have the right nutrition, they are more susceptible to diseases and pest infestations.
But that doesn’t mean you have to splurge on potting mix, especially if you are seeding out something that will be transplanted in a week or two. You can also amend a mix with compost. When amending, use at least 20% compost (35% is ideal). Use finished, not raw compost. Compost can be sourced from places like your municipality, garden centers, or other gardeners. But be sure the compost doesn’t contain herbicide residues, which can kill seedlings. For example, don’t use compost that’s been made from grass clippings that have been treated with broadleaf herbicides.
Container options for seed starting vary greatly and you can certainly get creative and even recycle and repurpose items like yogurt containers. Whatever container you choose, be sure it supplies adequate drainage (drill drainage holes if they aren’t present). A container also needs to hold its form through the entire seed starting process. Repeated watering can break down some transplant containers. Purchased or homemade paper containers are best suited for seeds that are only started a week or two before they are transplanted. Jiffy pots are a common container and work well. They are also compostable, but lose some of their structure after repeated waterings.
Planting the seed at the right depth is vital. Most seed packets will indicate the ideal depth. But if you don’t have access to that information, a good rule of thumb is that the seed needs to be planted at a depth twice the diameter of the seed. Lightly pack the soil in the container. Compacted soil can lead to poor root growth. Lightly water the seeds after planting. Start your hose or watering can away from the soil. A strong stream of water can wash away the soil and undo your careful sowing. Be sure to label your seeds too.
Nurturing Seeds Indoors
Like outdoor plants, indoor seedlings need the right conditions and environment in order to thrive. As you care for your planted seeds, keep these factors in mind:
Temperature: Look at the back of the seed packet to see what temperature your seeds need. As a general guideline, the optimal temperature for germination is often 5-10 degrees warmer than the optimal temperature for growth. (Onions are one exception.)
Light: Placing seedling containers in front of a window is often sufficient. Rotate the containers to encourage even plant growth.
Supplemental light source: If natural light isn’t adequate, use an additional light source, like a grow light. The light needs to be close enough to the container so that the seedlings don’t get spindly, but adjustable, to accommodate the height of growing plants.
Water: Overwatering is more detrimental than underwatering. Check the plants once a day, before noon and at the same time every day, and water as needed.
Humidity: You can cover watered plants with plastic domes to retain humidity. (Some people tuck containers in zippered plastic bags.) Remove the covering as soon as seeds have germinated (when you see green poking up from the soil) to allow for good air flow.
Fertilizer: Fertilize only as needed (typically four to six weeks after sowing, if you’re using a nutritive soil mix). If you are using compost and have sufficient soil in the pot, you don’t have to fertilize as soon or as often as you would if you are using a peat pot. (Peat-based potting mixes don’t have as much nutrients.)
Heat mats are essential for seeds that get a boost from bottom heat such as peppers, melons, and tomatoes. Bottom heat helps establish the plants roots.
Don’t fertilize a plant you’ll be taking out in a week or so to harden off (the process before transplanting a plant into the garden). And choose the right fertilizer for your needs. At Seed Savers Exchange, we use a fish emulsion to meet our organic growing requirements. Wait to fertilize until the plant is actively growing and fertilize at a low rate to avoid burning the plants.
The growth phase after germination is when problems tend to arise. Keep a close eye on your plants, especially for these common issues:
Pests. As you’re watering, check growth points and the undersides of leaves. Be especially mindful of pests if you have houseplants.
Damping off: Caused by botrytis, a fungus that occurs if humidity exceeds 85%. The condition comes on suddenly and is initially seen as seedling collapse. The stem withers and the seedlings topple over. The problem isn’t reversible, but can be prevented by maintaining good air circulation, not over-watering, and ensuring your soil medium is sterile. If damping off occurs, remove the affected seedling as soon as possible and maybe even some of the surrounding soil.
Leggy plants/spindly growth: Look at the lighting situation. If it’s been particularly cloudy or you live in a northern region, you may need to use supplemental lighting. High temperatures cause rapid growth and can also lead to leggy plants. Larger, older plants can also compete for light when they are close together. Space plants farther apart so that they don’t compete for resources.
Poor root growth: Poor drainage is one cause of poor root growth and can be prevented by using containers with adequate drainage. Too low temperatures and low fertility can also lead to poor root growth, as can compacted soil. When you are potting, make sure you don’t pack the soil too tightly.
Learn More About Starting Seeds Indoors
The New Seed Starters Handbook is the go-to guide for seed starting and includes guides for more than 200 plants, plus plenty of must-know tips and tricks.
Choose a large container that is at least 12 inches deep and wide. You can grow about four corn plants in this size of pot. Make sure your pot have enough drainage holes in the bottom.
Varieties for Growing Corn in Containers
As you grow corn in pots, choose a dwarf variety that does not exceed 4 or 5 feet (1.2 to 1.5 m) height. Some good choices are short stemmed ‘Trinity’ and ‘Sweet Painted Mountain’.
Sow four to six seeds per pot about 1 inch (2.5 cm) deep and rake a bit of soil above them. Don’t worry if the corn is planted together closely in a pot. In fact, sowing seeds closely helps in pollination and allow the corn to fruit abundantly.
Sweet corn needs full sun, plenty of water and fertile soil to thrive. It depends on the wind for pollination, which is best achieved when the corn is planted in a block of several short rows.
Mulch around the corn to hold in moisture. Use wood chips, newspapers or grass to help prevent moisture loss. Mulching also keeps weeds to a minimum.
Corn plants require soil that retains moisture without drying out quickly but drains well enough so it doesn’t become soggy or waterlogged. A peat based potting soil works best for them.
Water the plant every other day, keeping the soil constantly moist. Water is important ingredient to get sweet and soft corns, especially at the time of fruiting you’ll need to water your potted corns more.
Add fertilizer after 10 weeks from sowing. Dig a hole about 2 cm in depth and diameter around each plant. Pour 1/2 tablespoons of 5-10-10 or 10-20-20 fertilizer per plant, and incorporate the soil.
If you know how to grow corn in pots, you can grow your own corns without the need of lot of space, usually corns are ready to harvest between 60 to 100 days after planting, depending on the variety and weather conditions.
Growing Corn in Alaska
We get a lot of questions about growing corn in Alaska, so we took a second to sit down with farmer Carol Kenley who owns and operates Kenley’s Alaskan Vegetables and Flowers. Carol, along with her mother June, has been growing sweet corn in Alaska for 50 years.
Growing corn in Alaska is a labor of love, says Carol.
“We love the taste of fresh picked sweet corn and we grow it because we can,” said Carol who annually grows 300 plants- enough to feed her family and give some away to extended family and friends.
Start By Growing Your Corn Indoors
The process for growing sweet corn in Alaska takes some time. You need to start seedlings around April 27th. Carol grows the seedling under grow lights or starts them in her greenhouse. After sprouting, they transplant the sweet corn out into the fields by May 10th.
But here is where it gets a little tricky. You can’t just transplant them into the ground. you need to dig a hole for them, transplant the plant and then cover them with clear plastic entirely. They will stay under the plastic until the end of May in order to maximize the warmth underneath the plastic. You cut them out of the plastic at this point and the plants will be about two feet tall. If you miss out on this stage of under plastic growth, you are missing out on a significant period of growth for this sun loving plant. The old-adage is that one day in May is worth two in late July. Corn growis successfully in Alaska because we have the daylight length even if we don’t have the soil temps.
Carol applies a pre-emergent to the soil so she can leave the plastic down for the whole growing season. If you skip this step, you’ll need to pull up the plastic to weed.
Choose Your Corn Varieties Wisely
Carol’s biggest recommendation is to choose your varieties wisely.
Look for the the very shortest day length corn varieties. Look for for 65 day varieties in order to get ears on before frost. In good years (read warm years) Carol has harvested as early as July 27, in colder, wetter years harvest happens in mid-August. If you choose later varieties, you could be harvesting as late as mid-September.
Give Yourself Enough Space For the Corn To Grow
If you have room, then you can grow the corn, but you’ll need plenty of space. For each hill of corn you need a 2’ x 2’ space. That is a lot of space for a home gardener but if you’ve got a big garden patch, it might just be worth it for you. Each hill of corn gets maybe 2-3 ears, so if you’re trying to be economical, you may want to consider growing potatoes instead.
Growing Corn In Alaska: Sweeter by Far
Corn is one of those unfortunate crops that converts all of its simple sugars (which makes the sweetness) to longer storing starches. It explains why grocery store sweet corn tastes so starchy in Alaska. New varieties on the shelves have started to come in that maintain some of that sweetness, but Carol still says that picking it straight from the fields is the sweetest way to eat your sweet corn.