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Growing Sweet Corn: Varieties, Gene Types and Planting Information

Growing Sweet Corn: Varieties, Gene Types & Planting Information

Which sweet corn varieties can you plant together? 

Which sweet corn varieties should you avoid planting together?

One of the major types of Maize, sweet corn has been grown for at least two hundred years. Recorded in America as having been first introduced to European settlers by Iroquois Indians in 1776, sweet corn was the outcome of a naturally occurring genetic mutation in field corn[1]. Generally, the process of growing corn involves maturation, or the conversion of sugar to starch. In order to prevent this conversion and its resulting starchiness, sweet corn is harvested and either eaten, canned or frozen while in its milk stage (immature). This ensures that the kernels will remain tender and sweet.

By the 20th century sweet corn production began to evolve due to developmental influences. Such developments included:

Identification. Separate genetic groups, combined with genetic modifiers, are responsible for the varying levels of sweetness in corn[2]. Identifying this resulted in an ability to breed new varieties based on the three main genetic groups and their characteristics:

1. su  (normal sugary)

• su varieties are best when cooked within 30 minutes of harvesting

2. se  (sugary enhanced or Everlasting Heritage)

• se varieties have a longer storage life and contain 12-20% sugar compared to their su counterparts

3. sh2  (supersweet or shrunken-2)

• sh2 varieties kernels store less starch and anywhere from 4-10x more sugar than su varieties

Hybridization. This development involved breeding the superior or preferred qualities of two plants in order to produce better crop. Both tedious and beneficial, this process produces uniform maturity, improved quality and disease resistance in new plants.

There are a number of genetic variants for this well-liked vegetable and such variations result in the numerous selections of sweet corn you find in seed packets or on grocery shelves today. If you’re no expert, growing sweet corn may lead to quite a bit of frustration at times – especially when planting varieties together. When planting sweet corn se and su corn varieties do not need to be isolated from each other. However, sh2 supersweet varieties must be grown in isolation from other varieties to avoid cross-pollination and resulting starchiness.

Open-pollinated sweet corn varieties such as Golden Bantam remain popular for home gardeners even though they do not preserve well; often marketed as heirloom seeds – albeit less sweet – they are described as more tender and flavorful than hybrid varieties.

Modern breeding methods have also introduced varieties incorporating multiple gene types. They are normally marketed with brand names and/or trademarks by seed producers and offered as a choice of white, bi-color and yellow varieties which otherwise have very similar traits[3]. Please note that the colors of sweet corn kernels have no affect on taste/flavor of the corn. Still, when growing, isolate white kernel sweet corn varieties from yellow or bi-color varieties and bi-color kernel varieties from yellow varieties[4]. All sweet corn types should be isolated from field and popcorn types.

A list of sweet corn varieties as well as their gene types and other important growing information:

Bodacious Hybrid Corn | Days to Maturity: 75

se – Yellow | Mid-season with 8-inch ears having 18 rows of kernels. 7-foot stalks. Resistant to Stewart's wilt. Holds its flavor well after harvest.

– Butter Gold Corn

se – Yellow |  Superior cold soil emergence makes it ideal for the North, but ButterGold also does well anywhere other corn varieties are grown. Large 7 to 8-inch ears have 12 to 14 rows of juicy, yellow kernels. Excellent for freezing.

– Country Gentleman Corn

Open-pollinated – White |  Late-season heirloom with 8-inch ears on 6-foot stalks. One of the most unusual sweet corn varieties because the white kernels are arranged irregularly, not in rows. Also known as Shoepeg Corn. Developed around 1890 in Orange, Connecticut.

– Earlivee Corn

su – Yellow | Early-season with 7-inch ears well-filled to the tip with 12 to 14 rows of kernels. Stalks are only 5-feet tall. Harvest this while you have a later variety of corn waiting to mature in your garden.

Early Golden Bantam Corn | Days to Maturity: 75-80

su – Yellow | Excellent quality fresh and canned. Popular since the early 1900's. Plants yield two or more 5 to 7-inch ears on 5 to 6-foot stalks. The 8 to 12 rows of golden-yellow kernels have old-fashioned sweet corn taste. Widely adaptable.

– Early Sunglow Corn | Days to Maturity: 65

su – Yellow | Early-season with 6 to 7-inch ears having 12 rows of kernels. 5 to 6-foot plants grow well in adverse weather conditions.

– Extra Sweet 82 Corn


sh2 – Yellow | Mid-season, 9-inch ears on 5 to 6-foot plants. 14 to 18 rows of extremely tender and sweet kernels. Good variety for freezing. Do not plant too early, and avoid placing it where it can pollinate with other corns.

– Golden Beauty Corn

su – Yellow  | This All-American Selections Winner gives good yields of straight 7 to 8-inch ears with 10 to 12 rows of delicious golden-yellow kernels. Excellent quality fresh and canned. Golden Beauty is an early, versatile variety that will grow in just about any soil and in just about any climate

Golden Cross Bantam Hybrid Corn | Days to Maturity: 88

su – Yellow | Late-season with 7-1/2 to 8-inch ears on 7 to 8-foot plants. Expect 12 to 14 rows of yellow kernels per ear. This variety grows well in most all soils.

– Golden Jubilee Corn | Days to Maturity: 80-90

su – Yellow | Late to mature; not recommended in colder climates. Excellent for late season enjoyment in the South. Stalks are 6-feet with 8 to 9-inch ears. Best eaten very soon after picking.

– Honey & Cream Corn

su – Bi-color | Mid-season with 7-inch ears with 12 to 14 rows of kernels. 7-1/2 foot plants exhibit disease resistance. Nothing beats the old-fashioned flavor of this classic bi-color corn.

– Iochief Hybrid Corn

se – Yellow | Late-season with 9 to 10-inch ears with 14 to 18 rows of kernels. 7-foot plants with 2 ears per stalk. Drought resistant. All American Selections Winner.

– Jackpot Hybrid Corn

se – Bi-color | Mid- to late-season variety with resistance to common rust. Sturdy 6-1/2 foot plants bear 8-inch ears with 16 to 18 rows of kernels. The ears have strong fill and are covered with a medium green husk that offers good tip cover protection.

Kandy Korn Hybrid Corn | Days to Maturity: ~89

se – Yellow | Mid- to late-season with 8 to 8-1/2 inch ears in deep purple husks having 16 rows of kernels that retain their sweetness well after picking. The plants are a towering 8-1/2 feet with unique reddish stems. Tolerant of Stewart's wilt and common rust.

– Nk199 Hybrid Corn

su – Yellow | Mid-season with 8-inch ears with 18 to 20 rows of kernels. Great variety for freezing and canning. Expect high yields.

– Ornamental MC Corn | Days to Maturity: 110

INDIAN ORNAMENTAL >> Late-season Ornamental corn with bright, glossy, blue, yellow, red, white and purple kernels on 7 to 10-inch ears. About 20% of the ears have purple husks.

– Ornamental Rainbow Corn | Days to Maturity: ~110

INDIAN RAINBOW >> Late-season Open-pollinated Ornamental corn with multi-colored kernels on 6 to 7-inch ears. 15% of the ears have purple husks.

RAINBOW INCA>> Late-season Sweet corn with unusual multi-colored kernels – purple, red, yellow, blue and white. Plants are 7 to 10-feet. Harvest fresh for sweet corn, or, dry for ornamental use. Great for fall and Halloween decorations.

– Ornamental Seneca Mix Corn 

SENECA INDIAN >> Late-season Ornamental corn with red, blue, pink, and rich burgundy ears. Husks and stalks range from green to deep burgundy. Tall, sturdy plants bear 2 ears.

Peaches & Cream Hybrid Corn | Days to Maturity: ~83

se – Bi-color | Mid-season >> 82 days to maturity >> This variety may sometimes be called Honey & Cream, or, Sugar & Gold. The plant produces good yields of ears 7-1/2 inches and have 14 rows of creamy kernels.

Note there is also a Peaches & Cream su  (Normal Sugar) that is an early variety.

su – Bi-color | Early-season >> 70 days to maturity >> Stalks are about 5-1/2 feet and bear 6 to 8-inch ears.

– Serendipity Corn

se/sh2 (Triplesweet) – Bi-color | Mid-season with 8-inch ears with 16 to 18 rows of kernels. Phenomenal eating quality makes this a must to grow for fresh corn from your garden. Isolate from other varieties.

Silver N Gold Corn | Days to Maturity: ~65

se – Bi-color | Early-season variety has an excellent balance of sweet to rich corn flavor. Plants have 8 to 8-1/2 inch ears covered with 12 to 16 slightly irregular rows of kernels typical of shoepeg types. Since Silver’N’Gold is such an early performer, you can extend production by staggering your planting to extend your season.

Silver Queen Corn | Days to Maturity: ~85

se – White | Late-season. The most widely recognized white corn variety; a standard for decades! 7 to 8-foot plants bear 8-inch, slightly tapered ears with 14 to 16 rows of kernels in tight husks and filled to tip. Tolerant of Stewart's wilt and northern corn leaf blight.

– Stowells Evergreen Corn 

Open-pollinated – White | Late-season. An 1848 heirloom variety from New Ipswich, Massachusetts. The plants bear one or two ears 8 to 9-inches with 14 to 20 rows of white kernels. This variety has excellent flavor and tenderness. A favorite variety for true “old-time” home-grown corn taste.

– Sugar Dots Hybrid Corn

su – Bi-color | Developed by Ferry-Morse. Mid- to late-season 6 to 8-foot plants bear 8-inch ears with 16 to 18 rows of kernels. Excellent quality corn.

– Xtra Tender 175A Corn

sh2 – Yellow | Early- to mid-season variety. If you have never had a super sweet variety, you are in for a treat. 175A has exceptional tenderness and flavor. In fact, even without butter it still tastes incredible.

1. Sweet corn, Wikipedia

2. Sweet Corn Genotypes, Vern Grubinger, 2004

3. Sweet corn, Wikipedia

4. Sweet Corn Genetics and Isolation, Seminis

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