Add it to your home screen and it opens full screen: no browser bars, one tap away, and everything stays signed in. Free, nothing to download from an app store.
- Tap the Share button in your browser
- Scroll down and choose “Add to Home Screen”
- Open GrowSomeFood from your home screen
- Open your browser’s menu
- Choose “Add to Home screen” or “Install app”
- Open GrowSomeFood from your home screen
Sweet Corn
The taste-of-summer crop: a tall wind-pollinated grass grown for sweet ears best eaten minutes off the stalk - plant it in a block and give it heat, sun, and rich soil.
No toxic parts. Corn allergy is uncommon; the edible corn smut fungus (huitlacoche) that sometimes forms on ears is a delicacy, not a poison, but discard ears with any other mold.
Overview
Sweet corn is the crop people grow for one reason: an ear picked and cooked within the hour is a different food from anything a store can sell, because its sugars start converting to starch the moment it's picked. A tall annual grass native to the Americas, corn asks for full sun, rich soil, plenty of nitrogen and water, and warmth - and it takes up real space, since it must be grown in a block to pollinate.
That block is the key idea. Corn is wind-pollinated: pollen drops from the tassels at the top onto the silks of the ears below, and each silk that catches a grain becomes one kernel. A single long row pollinates poorly and gives gap-toothed ears, so corn is always planted in a square block of several short rows. Sweet corn comes in three sugar genetics - standard (su), sugary-enhanced (se), and supersweet (sh2) - plus yellow, white, and bicolor, all grown the same way. (Growing corn to dry - cornmeal, masa, popcorn, decoration - is its own crop: see Grain Corn & Popcorn in the catalog.)
Quick facts
- Sprouts in
- 7 days5 to 14
- Soil to sprout
- 75 °F60 to 95
- Life cycle
- Annual
- Seed to save
- About 110 days after planting100 to 120
- Height
- 7 ft4 to 9
- Spread
- 18 in12 to 24
- Cold
- Killed by frostdamaged below 32°F
- Heat
- Struggles above 95°F
Full sun · medium water · well-drained soil · 10 in apart (8 to 12) · direct sow
When to plant
Nothing is open today. Spring sowing opens 7 months, Apr 17 to May 1.
- Direct sow Apr 17 – May 1 Opens in 208 daysAbout 7 days after to 3 weeks after your last frost (Apr 10 here)Wait a week or so past last frost, until soil hits 60°F (65°F for supersweet) - corn is frost-tender and cold wet ground rots the seed. Succession-sow every 10-14 days, or plant early/mid/late varieties together, to spread the harvest.
- Direct sow Jul 7 – Aug 1 Opens in 289 daysAbout 16 weeks before to 12 weeks before your first frost (Oct 25 here)A last sowing of an early variety 12-16 weeks before frost stretches fresh corn into September.
Frost here: last around Apr 10 (Mar 27 to Apr 24 most years), first around Oct 25. Zone averages, your own yard may run a week or two either way.
Life stages
Six stages, about 11 weeks from sowing to the first pull. Windows are typical; your zone and weather move them.
Germination
Day 0 to 8 from sowing- WaterKeep the seedbed moist but not soggyevery 2 daysCorn needs even moisture to sprout; supersweet (sh2) seed is shriveled and rots easily in cold wet soil, so don't overwater.
- ProtectSow only into warm soil (60°F, 65°F for supersweet)Cold soil gives poor, patchy stands. Standard sweet corn wants 60°F; supersweet types need 65°F+ for reliable germination.
Watch for- Patchy emergence (cold soil or seed-corn maggot)
- Birds and crows pulling up sprouting seeds
Seedling
Day 8 to 24 from sowing- ThinThin to 8-12 inches apart in the blockCrowded corn makes thin stalks and poorly filled ears; thin to final spacing once plants are a few inches tall.
- WeedWeed while plants are smallevery 10 daysYoung corn competes poorly; cultivate shallowly to avoid its near-surface roots.
Watch for- Cutworms felling seedlings
- Flea beetles (which can spread Stewart's wilt)
- Purple leaves (cold, or phosphorus in cold soil)
Vegetative
Day 24 to 55 from sowing- FertilizeSide-dress nitrogen when knee-highmonthlyCorn is a heavy nitrogen feeder; a side-dressing when plants are 12-18 inches (and again at tasseling) drives the ear-filling to come.
- WaterWater deeply about an inch a weekweeklySteady moisture builds the stalk and root system; deep watering encourages the prop roots that keep tall corn standing.
- MulchMulch and don't disturb the shallow rootsHilling a little soil around the base supports the stalks; avoid deep cultivation near the roots.
Watch for- Yellowing lower leaves (nitrogen hunger - feed now)
- Leaning plants in wind (hill soil at the base)
- Long gray-green lesions (leaf blight) in wet weather
Tasseling & silking (pollination)
Day 58 to 78 from sowing- PollinatePlant in BLOCKS (4x4 minimum), not single rowsCorn is wind-pollinated: pollen falls from the top tassels onto the silks below. A block of short rows catches far more pollen than one or two long rows - the single most important thing for full ears. Hand-pollinate small plantings by shaking tassels over the silks on a dry morning.
- WaterNever let corn go dry during pollinationevery 3 daysDrought or heat above 95°F during tasseling/silking kills pollen and causes gappy, half-filled ears. Water is critical for these two weeks.
Watch for- Heat wave during silking (partly filled ears - unavoidable, but water helps)
- Corn earworm moths laying eggs on fresh silks
- Missing kernels/gaps (poor pollination - block planting fixes it)
Ear fill (milk stage)
Day 72 to 95 from sowing- WaterKeep watering steady as ears fillevery 4 daysKernels plump with sugar and water now; consistent moisture makes full, juicy ears. Ears are ready about 18-24 days after the silks emerge.
- ProtectGuard ripening ears from raccoons and birdsRaccoons raid the night before you'd pick - the classic heartbreak. Electric fencing, a radio, or bags over ears help; birds peck exposed tips.
Watch for- Corn earworm damage at the ear tip
- Raccoons testing ears (they strike just before ripe)
- Silks browning and drying (harvest is near)
Harvest
Day 60 to 95 to the first pull from sowing- HarvestPick at the milk stage - brown silks, plump kernelsevery 2 daysReady when silks are brown and dry, the ear feels full to the tip, and a punctured kernel squirts milky (not clear, not doughy) juice. The whole planting ripens within about a week; check daily.
- HarvestTwist down and pull; cook or chill it fastGrasp the ear, twist down, and snap it off. Sugar starts turning to starch the moment it's picked - eat, chill, or freeze sweet corn as soon as possible (old su types within hours; supersweets hold longer).
Watch for- Doughy, dented kernels (overripe - past peak sweetness)
- The whole block ripening at once (why succession or mixed varieties help)
- Raccoons the night before harvest
Harvest
- Silks have turned brown and dry
- Ear feels full and rounded to the tip through the husk
- A punctured kernel releases milky (not clear or pasty) juice
- Pick at the milk stage - brown silks, plump kernels · every 2 days
- Twist down and pull; cook or chill it fast
Per plant 1 to 2 ears, 8 to 24 ozPicking pull once
Cook with Sweet Corn
Watch out for
8 to know. 2 are high-risk: Corn Earworm, Raccoons. 5 are active in September.
Corn EarwormSeverity High PestnowThe same insect as the tomato fruitworm and cotton bollworm, which is why corn and tomatoes shouldn't be planted side by side.
Chewed, discolored kernels and dark frass at the ear tip, and a fat caterpillar (green, brown, or pink) inside the husk near the top.
Damage is usually confined to the tip - just cut it off. Bt sprayed on silks catches young larvae; the ear below is fine to eat.
Choose varieties with tight husk tips; a few drops of vegetable or mineral oil (with a little Bt) on the silk 5-6 days after silking smothers young larvae; encourage natural enemies.
The most common sweet-corn pest: a night-flying moth lays eggs on fresh silks, and the caterpillar tunnels down into the ear tip to feed on developing kernels.
RaccoonsSeverity High WildlifenowRaccoons have an uncanny sense of ripeness - the classic gardener's heartbreak is losing the crop the night before harvest.
Defenses must be up before ears ripen.
Stalks pulled or broken down overnight, husks torn open, and half-eaten ears scattered on the ground - a whole patch can be lost in one night.
Reinforce fencing immediately at first sign; once raccoons find a patch they return nightly until it's gone.
A two-strand electric fence (at ~6 and 12 inches) is the most reliable defense; also try bagging individual ears in mesh, a radio playing in the patch, or a dog nearby. The Three Sisters' prickly squash vines underfoot help deter them.
The single greatest threat to home sweet corn: raccoons raid the patch at night, often the very night before the ears are ripe, tearing down stalks and stripping ears.
Corn SmutSeverity Medium DiseasenowThe spores persist in soil for years, so remove galls before they burst; the same fungus that ruins an ear is a gourmet ingredient when young.
Grotesque silvery-gray swollen galls replacing kernels on the ear (or on tassels/stalks), which later burst into masses of black spores.
No spray cure - cut out and destroy galls early. Note: young, firm galls are the prized Mexican delicacy huitlacoche ('corn mushroom'), genuinely delicious cooked.
Avoid wounding plants, keep them evenly watered and unstressed, rotate, and remove and destroy galls before they blacken and release spores (don't compost them).
A fungus that turns kernels into swollen, gray-white then black galls on ears, tassels, and stalks, favored by heat, drought stress, and plant injury.
Common RustSeverity Medium DiseaseCommon on late plantings in humid regions; resistant varieties make it a non-issue in most home gardens.
Small, oval, rust-colored raised pustules scattered on leaves (upper and lower), rubbing off as reddish powder, later turning dark.
Usually tolerable on sweet corn maturing before it peaks; remove badly infected lower leaves, and fungicides are rarely needed in home gardens.
Plant resistant hybrids (most modern ones are), give good airflow and full sun, and avoid overhead watering; rust blows in on wind so timing helps.
A fungal disease producing cinnamon-brown pustules on both leaf surfaces, favored by cool, humid weather; heavy infection cuts photosynthesis and yield.
Corn RootwormSeverity Medium PestAlmost entirely a problem of corn-after-corn; simply rotating the planting site each year prevents it in home gardens.
Plants leaning or 'goose-necked' from root damage, easy to pull up, and slender striped or spotted beetles feeding on silks and pollen at flowering.
No rescue for damaged roots; rotation is the control. Heavy adult silk-clipping at pollination can be reduced by hand-pollinating.
Rotate corn to a different bed each year - the larvae starve without corn roots, so rotation nearly eliminates them; this is the classic reason not to grow corn in the same spot two years running.
Beetle larvae that feed on and tunnel through corn roots, causing plants to lodge (fall over) and lose vigor; adults also clip silks and interfere with pollination.
European Corn BorerSeverity Medium PestBroken tassels and stalks lodging in wind are the usual signs; fall stalk destruction is the best home defense.
Small entry holes with sawdust-like frass on stalks and leaf axils, broken tassels, and tunneling into the ear from the side.
Once inside the stalk, larvae are protected from sprays - control relies on prevention, fall cleanup, and Bt on early larvae.
Rotate crops, shred and destroy old cornstalks in fall (larvae overwinter in them), and plant resistant hybrids; Bt-timed sprays target young larvae before they bore in.
A moth larva that bores into stalks, leaf midribs, and ears, weakening stalks so they break and opening the plant to rot.
2 more, low risk
Gray Leaf SpotSeverity Low DiseasenowPrimarily a continuous-corn and no-till field disease; rotation in a home garden largely prevents it.
Narrow, rectangular gray-brown lesions running parallel between the leaf veins, expanding and merging in humid weather.
Seldom needs treatment in home gardens; focus on rotation, resistant varieties, and debris cleanup.
Rotate away from corn, bury or remove residue, space for airflow, and plant resistant hybrids; it survives in old cornstalks.
A fungal disease making small rectangular gray-to-tan lesions bounded by leaf veins, worst in warm, humid, no-till conditions.
Northern Corn Leaf BlightSeverity Low DiseasenowMore a concern for field and late-season corn than for early-maturing home sweet corn; resistant varieties handle it well.
Elongated (1-6 inch) gray-green to tan lesions on the leaves, starting low and moving up, that can merge and blight whole leaves.
Rarely warrants treatment in home gardens on sweet corn maturing before infection peaks; remove badly affected debris after harvest.
Rotate crops, plant resistant hybrids, and clean up crop debris where the fungus overwinters; good spacing and airflow slow it.
A fungal leaf disease causing long, cigar-shaped gray-green lesions that reduce the plant's photosynthetic area in wet, moderate-temperature weather.
Good & bad neighbors
Plant nearby
-
The Three Sisters: beans climb the cornstalks and fix nitrogen the hungry corn uses. A genuinely functional, centuries-proven pairing.
-
The third of the Three Sisters: sprawling squash shades the soil, holds moisture, and its prickly vines deter raccoons and weeds beneath the corn.
- Traditional pairings, thin evidence
-
Traditionally grown at the edge of corn to draw pollinators and birds; keep it from shading the corn, since sunflowers also compete and are mildly allelopathic.
Keep apart
-
Fennel's root exudates inhibit most vegetables; keep it well away.
-
Corn earworm and tomato fruitworm are the same insect - adjacent plantings feed the shared pest - and both are heavy feeders.
- Traditional pairings, thin evidence
-
BrassicasTraditional advice that heavy-feeding brassicas compete with heavy-feeding corn and share some pests; evidence is thin.
Varieties · 27
You pick one when you add Sweet Corn to your garden. Its days to maturity set your harvest window.
Standard (su) 7 varieties
Silver Queen
Large 8-9 inch ears packed with creamy-white kernels on tall plants.
suwhitelateclassicThe legendary late-season white sweet corn, long the gold standard for flavor: tall, vigorous, disease-tolerant plants and large ears of tender, creamy-white kernels. A standard (su) type, so eat it fresh - it doesn't hold sweetness long. Synonymous with summer barbecues.
Golden Bantam
Slim 5-7 inch ears with bright golden-yellow kernels.
suyellowheirloomopen-pollinatedThe 1902 heirloom that made yellow sweet corn popular (before it, white was preferred): rich old-fashioned corn flavor on shorter 5-6 foot plants. Open-pollinated, so you can save seed. A standard sugary type best eaten straight off the stalk.
Sugary-Enhanced (se) 8 varieties
Ambrosia
8-inch ears with a bicolor mix of white and yellow kernels.
sebicolormidseasonResists Rust, Smut
One of the most popular home-garden bicolors: a sugary-enhanced (se) hybrid with an outstanding sweet, tender balance of yellow and white kernels and good disease resistance. Holds its sweetness longer than su types - a reliable crowd-pleaser.
Peaches and Cream
8-9 inch ears with alternating white and yellow kernels.
sebicolormidseasonA classic bicolor sugary-enhanced corn named for its creamy texture and mix of pale and yellow kernels. Tender, sweet, and popular for fresh eating; a dependable garden bicolor.
Supersweet (sh2) 10 varieties
Early Xtra Sweet
Uniform ears with bright-yellow, high-sugar kernels.
sh2yellowearlyResists Rust, Stewart's Wilt
An early supersweet (sh2) hybrid with very high sugar content and long-holding sweetness, unusually early for a supersweet. Isolate it from other corn to keep its sweetness pure.
Heatwave
Full ears of bright-yellow, high-sugar kernels.
sh2yellowheat-tolerantResists Rust, Smut
A supersweet hybrid bred to set and fill ears in high heat where other corn fails to pollinate - a good pick for hot-summer regions.
Flint / dry corn (not sweet corn) 1 variety
Molokai
Colorful ears, often with deep purple or near-black kernels, left to harden and dry on the stalk.
tropicalmulticolorA distinctive Hawaiian flint corn, often bearing deeply colored purple-to-black kernels. Unlike every sweet corn around it, this one is grown to DRY - for meal, for decoration, and for its looks - not picked and eaten fresh at the milk stage. It is typed here as flint corn, so its readiness signs are the dry-down ones: leave the ears on the stalk until the husks are papery and the kernels are hard, then shell and store them. See the Grain Corn and Popcorn entry for the fuller drying-corn crop model.
Other varieties 1 variety
Honey Select
8-9 inch ears with plump, deep golden-yellow kernels.
synergisticyellowmidseasonaas-winnerResists Rust, Stewart's Wilt
A 2001 All-America Selections winner and a 'synergistic' triple-sweet type combining se and sh2 kernels on one ear for exceptional tenderness and sweetness that holds well. Large golden ears; one of the best-tasting yellow hybrids.
Grower tips
Notes from growers, tagged with the zone they grow in. A person reads every post before it appears.
Nobody has posted about Sweet Corn yet. The first one usually saves someone a season.
Free account. Your post shows your grower name and zone, never your email.