Sweet corn

Zea mays · Grass family (Poaceae)

At a glance
Hardiness zones	3 to 11
Sun	full sun
Water	moderate
Life cycle	annual
Frost	Tender: killed by frost
Soil pH	5.8–7.0
Spacing	8 to 12 inches
Days to harvest	63 to 92 days
Soil temperature to plant	at least 55°F

About Sweet corn

Sweet corn is a summer favorite that is wind-pollinated, so it must be planted in blocks rather than a single row. Standard, sugar-enhanced and supersweet types differ in sweetness and must be kept apart to avoid cross-pollination.

Grown as a warm-season annual in every zone; it is killed by frost, so plant it out after the danger of frost has passed.

When to plant

Timing is counted from your average last spring frost (and first fall frost). Sow & Tell works out the actual dates for your ZIP code.

Sow seeds outdoors: up to 2 weeks after the last frost

Days count from seeding. Standard types need soil above 55F and supersweets about 65F. Plant at least four short rows side by side, and sow again when the last planting has 3 to 4 leaves.

Soil

Well-drained soil with plenty of organic matter; corn is a heavy feeder with shallow roots.

Follow a soil test and keep pH about 6.0 to 7.0; work in compost, and without a test add about 30 lb of 5-10-10 per 1,000 sq ft (about 3 lb per 100 sq ft) before planting.

Feeding

when plants are about knee high (12 to 18 inches, about 8 to 10 leaves): nitrogen fertilizer such as 21-0-0 or 46-0-0. Use about 1/2 lb of 21-0-0 per 100 sq ft, or 1/2 cup of 46-0-0 per 100 ft of row, about 6 inches from the plants, then water it in.
when the first tassels or silks appear: nitrogen fertilizer such as 21-0-0. Add about 1/4 lb of 21-0-0 per 100 sq ft about 6 inches from the plants and water it in.

Keep fertilizer about 6 inches from the stalks because corn is easily hurt by fertilizer salts; never use weed-and-feed products.

Harvest

Pick about 18 to 24 days after silks appear, when silks are dry and brown, the ear feels full to the tip, and a punctured kernel gives milky juice.

Pick ears once, when kernels in the middle of the ear are full and give milky juice; the stalk is then done.

Varieties (51)

Variety	Type	Days	Notes
Golden Bantam	Heirloom, yellow		An heirloom yellow sweet corn first introduced in 1902.
Bi-Queen	Standard (su), bicolor		Very sweet with a very tender kernel skin. Hybrid bicolor version of Silver Queen.
Butter and Sugar	Standard (su), bicolor	75 to 82 days	Classic sweet corn flavor with creamy kernels; eat soon after picking because sugar turns to starch quickly. Bicolor ears with 12 to 14 rows of yellow and white kernels.
Honey and Cream	Standard (su), bicolor	80 days	Yellow and white kernels on ears with 12 to 14 rows.
Sweet G90	Standard (su), bicolor	80 to 90 days	Very tender and sweet. Bicolor hybrid recommended across several Texas regions and Mississippi.
Silver Queen	Standard (su), white	91 to 95 days	Standard (su) sweetness; sugar turns to starch soon after picking, so harvest it the day it will be eaten. Late, white corn with 14 to 18 rows of kernels. Resists rust, Stewart's wilt and corn leaf blights.
Earlivee	Standard (su), yellow	63 days	Very early hybrid with well-filled, attractive ears of 10 to 14 rows and almost no suckers.
Early Sunglow	Standard (su), yellow	63 days	Classic sweet corn flavor with creamy kernels; eat soon after picking because sugar turns to starch quickly. An early yellow sweet corn.
Golden Cross Bantam	Standard (su), yellow	80 to 85 days	Yellow-kerneled corn with 12 to 14 rows per ear.
Golden Queen	Standard (su), yellow	92 days	Classic sweet corn flavor with creamy kernels; eat soon after picking because sugar turns to starch quickly. Late yellow corn with northern corn leaf blight resistance.
Jubilee	Standard (su), yellow	82 days	Classic sweet corn flavor with creamy kernels; eat soon after picking because sugar turns to starch quickly. A yellow hybrid on Utah State's and Kansas State's lists.
Merit	Standard (su), yellow	75 to 84 days	Classic sweet corn flavor with creamy kernels; eat soon after picking because sugar turns to starch quickly. Yellow corn with 16 to 20 rows of kernels.
Sundance	Standard (su), yellow	71 days	Short, sturdy hybrid with 7.5 to 8-inch ears of 12 to 16 rows.
Stowell's Evergreen	Standard, white, heirloom		An heirloom, late-season white sweet corn.
Luscious	Sugar-enhanced (se)	75 days	Large, blocky ears filled with sweet kernels. Easy to pick.
Ambrosia	Sugar-enhanced (se), bicolor	75 days	Sweeter and more tender than standard types, and holds its sweetness a few days longer. Main-season bicolor hybrid. Resists Stewart's wilt.
Delectable	Sugar-enhanced (se), bicolor	80 days	Sweeter and more tender than standard types, and holds its sweetness a few days longer. Main-season bicolor hybrid. Resists rust.
Peaches and Cream	Sugar-enhanced (se), bicolor	83 days	Tender, with very good eating quality. Productive bicolor hybrid with tender kernels. Resists southern and northern corn leaf blight.
Trinity	Sugar-enhanced (se), bicolor	68 days	Sweeter and more tender than standard types, and holds its sweetness a few days longer. Early to midseason bicolor hybrid.
Argent	Sugar-enhanced (se), white	80 to 86 days	Excellent eating quality. Midseason white hybrid. Resists northern corn leaf blight, rust and Stewart's wilt.
Platinum Lady	Sugar-enhanced (se), white	80 days	High eating quality. White kernels and white silks, with about 14 rows per ear.
Silver King	Sugar-enhanced (se), white	82 days	Sweeter and more tender than standard types, and holds its sweetness a few days longer. White hybrid with large ears. Resists northern corn leaf blight, Stewart's wilt and rust.
Silver Princess	Sugar-enhanced (se), white	75 days	Sweeter and more tender than standard types, and holds its sweetness a few days longer. White hybrid that resists northern corn leaf blight, Stewart's wilt and rust.
Sweet Ice	Sugar-enhanced (se), white	74 days	White corn with 7-inch ears of 14 to 16 rows, good tip fill and dark green husks.
Bodacious	Sugar-enhanced (se), yellow	75 days	Excellent eating quality; sweeter and more tender than standard types, and holds its sweetness a few days longer. Yellow hybrid that adapts to many regions. Resists rust.
Incredible	Sugar-enhanced (se), yellow	85 days	Sweeter and more tender than standard types, and holds its sweetness a few days longer. Late yellow hybrid. Resists northern corn leaf blight, rust and Stewart's wilt.
Kandy Korn	Sugar-enhanced (se), yellow	83 to 89 days	Sweeter and more tender than standard types, and holds its sweetness a few days longer. A long-standing yellow se hybrid.
Miracle	Sugar-enhanced (se), yellow	82 to 85 days	Sweeter and more tender than standard types, and holds its sweetness a few days longer. Yellow hybrid with large ears. Resists northern corn leaf blight, rust and Stewart's wilt.
Sugar Buns	Sugar-enhanced (se), yellow	70 to 72 days	Sweeter and more tender than standard types, and holds its sweetness a few days longer. An early, high-quality yellow se hybrid.
Troubadour	Supersweet (sh2)	82 days	Outstanding flavor. Holds well in the field. Germinated well and produced large ears in North Dakota trials.
Xtra-Tender 274A	Supersweet (sh2)		Tender kernels. Ripened early and produced large ears in North Dakota trials.
American Dream	Supersweet (sh2), bicolor		Bicolor supersweet recommended in both Georgia and North Dakota.
Candy Store	Supersweet (sh2), bicolor	81 days	Bicolor supersweet hybrid from Harris Moran.
Honey 'n Pearl	Supersweet (sh2), bicolor	76 to 78 days	Very sweet, crisp kernels that stay sweet for about a week in the refrigerator. Sturdy plants with large, well-filled ears about 8.5 inches long and 16 to 18 rows. An All-America Selections winner.
Obsession	Supersweet (sh2), bicolor	73 to 79 days	Very sweet, crisp kernels that stay sweet for about a week in the refrigerator. Bicolor with ears about 8.5 inches long and 18 to 20 rows. Resists northern corn leaf blight, rust and Stewart's wilt.
How Sweet It Is	Supersweet (sh2), white	85 to 87 days	Very sweet, crisp kernels that stay sweet for about a week in the refrigerator. One of the first white supersweet hybrids and an All-America Selections winner.
Early Xtra Sweet	Supersweet (sh2), yellow	68 to 70 days	Very sweet, crisp kernels that stay sweet for about a week in the refrigerator. Early yellow supersweet with ears about 7.5 inches long.
Illini Xtra Sweet	Supersweet (sh2), yellow	85 days	Very sweet, crisp kernels that stay sweet for about a week in the refrigerator. A yellow supersweet hybrid on Utah State's list.
Northern Xtra Sweet	Supersweet (sh2), yellow	63 to 67 days	Very sweet, crisp kernels that stay sweet for about a week in the refrigerator. Very early yellow supersweet with ears about 9 inches long.
Supersweet Jubilee	Supersweet (sh2), yellow	82 to 87 days	Very sweet, crisp kernels that stay sweet for about a week in the refrigerator. Late yellow supersweet that resists rust.
Vision	Supersweet (sh2), yellow	75 days	Very sweet, crisp kernels that stay sweet for about a week in the refrigerator. Yellow supersweet that resists rust and southern corn leaf blight.
Montauk	Synergistic (se + su), bicolor	81 days	Very sweet, crisp and tender kernels. Bicolor synergistic hybrid.
Mirai	Synergistic (su + se + sh2)	70 to 76 days	Very sweet, crisp and tender kernels. A family of hybrids (yellow, bicolor and others) with ears around 7.75 inches and good tip fill.
Honey Select	Synergistic / triple sweet (se + sh2), yellow	79 days	Very sweet, crisp and tender kernels. Yellow triple-sweet hybrid. Resists Stewart's wilt.
Providence	Synergistic / triple sweet, bicolor		Triple-sweet type with long, well-filled, slightly tapered ears.
Serendipity	Synergistic / triple sweet, bicolor	82 days	Very sweet, crisp and tender kernels. Bicolor triple-sweet hybrid.
Avalon	Synergistic / triple sweet, white	82 to 84 days	Very sweet, crisp and tender kernels. The first white variety in the Triple Sweet line.
Celestial	Synergistic, white	87 days	White synergistic corn listed with resistance to northern corn leaf blight and rust.
Country Gentleman	White, Country Gentleman type	92 days	White corn of the old Country Gentleman type.
Snowbelle	White, hybrid	79 to 85 days	Very tender and sweet, with a creamy texture. White hybrid that ripens about 5 to 7 days before Silver Queen.
Spring Treat	Yellow	66 days	Very sweet yellow kernels. Very early corn that does well in cool soils and is easy to harvest.

Good neighbors

Green beans (snap beans), Winter squash and pumpkin, Lettuce

UMN and UMD Extension describe the Three Sisters (corn, beans, squash) as a long-used Indigenous system; shade-tolerant greens can go on the north side of corn.

Pests to watch for

Corn earworm (tomato fruitworm), Flea beetles, White grubs, Aphids, Cutworms, Grasshoppers, Stink bugs, Harlequin bug, European earwig, Squash beetle, Corn rootworms, Raccoon, Red imported fire ant, Garden symphylan, Rose chafer, Green June beetle (fig-eater), Fall armyworm, Beet armyworm, European corn borer, Seedcorn maggot, Blister beetles, Deer, Tree squirrels

Diseases and problems

Smut, Stewart's wilt, Leaf rust, Poor pollination, Hail and wind damage, Nitrogen deficiency, Magnesium deficiency, Frost and freeze injury

In the kitchen

Boiled, grilled or roasted on the cob, or cut off for salads, soups and salsas; sugary types lose sweetness fast after picking.

Keeping it: Corn loses sweetness fast: refrigerate ears in their husks and eat them within 1 to 2 days. For preserving, work within a few hours of picking.

Pets: Not listed as toxic by the ASPCA (its toxic 'corn plant' entry is the houseplant Dracaena fragrans, not sweet corn).

Sources

Photo: Photo: Heidi Meudt, CC BY-SA 4.0, via Wikimedia Commons (CC BY-SA 4.0). Photo resized for the web.

Planting dates and advice are general guidance; check with your local Cooperative Extension office for your area.