Planting Timeline
Showing dates for Early Sunglow in USDA Zone 7
All Zone 7 corn →Zone Map
Click a state to update dates
Early Sunglow · Zones 3–10
Growing Details
Zone-by-Zone Planting Calendar
| Zone | Indoor Start | Transplant | Direct Sow | Harvest |
|---|---|---|---|---|
| Zone 3 | — | — | June – June | August – September |
| Zone 4 | — | — | May – July | July – September |
| Zone 5 | — | — | May – July | July – September |
| Zone 6 | — | — | May – July | July – October |
| Zone 7 | — | — | April – August | June – October |
| Zone 8 | — | — | March – September | May – November |
| Zone 9 | — | — | March – October | May – December |
| Zone 10 | — | — | February – October | April – December |
Complete Growing Guide
Early Sunglow thrives with proper site preparation and timing. Choose your sunniest garden spot with loose, fertile soil that drains well but retains moisture. Work in 2-3 inches of compost or well-aged manure before planting, as corn is a heavy feeder that demands rich soil.
Skip starting indoors—corn hates transplanting and performs best when direct sown. Wait until soil temperature consistently reaches 60°F, typically 2 weeks after your last frost date. In zones 3-5, this usually means mid to late May. Plant seeds 1 inch deep in heavy soils, 1.5 inches in sandy soils, spacing them 6-8 inches apart in rows 30 inches apart. Most importantly, plant in blocks of at least 4 rows rather than single long rows to ensure proper wind pollination.
Fertilize with a balanced fertilizer (10-10-10) at planting, then side-dress with nitrogen when plants reach knee-high, around 18 inches tall. Avoid high-nitrogen fertilizers late in the season as they promote leafy growth at the expense of ear development.
Maintain consistent moisture throughout the growing season, especially during silk emergence and ear filling. Corn needs about 1 inch of water weekly. Mulch around plants to retain moisture and suppress weeds, but keep mulch 6 inches from stalks to prevent pest harboring.
Avoid the common mistake of planting too early in cold soil—seeds will rot rather than germinate. Also resist the urge to remove suckers (side shoots) as they actually help support the main stalk and contribute to overall plant vigor. In windy areas, hill soil around the base of stalks when they're 12 inches tall to prevent lodging.
Harvesting
Early Sunglow reaches peak sweetness 18-20 days after silk emergence, when silks turn brown and feel dry to the touch. The kernels should appear plump and milky when punctured with a fingernail. Perform the classic squeeze test—gently squeeze an ear through the husk; it should feel firm and full with kernels reaching nearly to the tip.
Harvest in early morning when sugar content is highest and temperatures are cool. Grasp the ear firmly and twist downward while pulling away from the stalk. The ear should snap off cleanly. If it resists, it may not be fully mature. Check ears daily once they begin maturing, as the window for peak sweetness lasts only 3-5 days. Early Sunglow holds its quality better than many varieties, but still converts sugars to starch rapidly after picking. Harvest only what you can use within 24 hours for best flavor.
Storage & Preservation
Fresh Early Sunglow corn is best used immediately but can be stored unhusked in the refrigerator for up to 3 days. Keep husks on and store in perforated plastic bags to maintain humidity while allowing air circulation.
For longer storage, blanch whole ears in boiling water for 4 minutes, cool in ice water, then cut kernels from cobs and freeze in airtight containers for up to 12 months. Early Sunglow's tender kernels also excel when pressure canned—process pints for 55 minutes at 10 pounds pressure. The variety's good sugar retention makes it excellent for corn relish or pickled corn salad. Avoid dehydrating as the kernels become tough and lose their characteristic sweetness.
History & Origin
Early Sunglow was developed by agricultural researchers in the mid-20th century as part of the push to create reliable sweet corn varieties for northern growing regions. This hybrid emerged from breeding programs focused on combining early maturity with improved flavor—addressing the common complaint that early varieties sacrificed taste for speed.
The variety represents the evolution of sweet corn breeding beyond simple su (sugary) types toward improved sugar retention and tenderness. Early Sunglow was specifically selected for its ability to maintain sweetness longer after harvest compared to older early varieties, making it practical for home gardeners who couldn't always harvest and consume immediately.
Developed during the era when hybrid vigor was revolutionizing corn production, Early Sunglow demonstrates how plant breeders successfully adapted sweet corn for diverse growing conditions while maintaining the eating quality that makes fresh corn a summer staple across North America.
Advantages
- +Exceptional sugar retention after harvest compared to other early varieties
- +Reliable germination in cooler soil temperatures down to 60°F
- +Strong stalks resist lodging even in windy conditions
- +Ears fill completely to the tips with minimal kernel gaps
- +Good husk coverage protects ears from corn earworm damage
- +Performs consistently across diverse soil types
- +Kernels remain tender even when slightly overripe
Considerations
- -Limited to 1-2 ears per plant, reducing overall yield
- -Requires block planting of at least 16 plants for proper pollination
- -Stalks decompose slowly, making fall cleanup tedious
- -More susceptible to southern corn leaf blight in humid conditions
Companion Plants
Plant Together
Lettuce
Benefits from corn's partial shade during hot weather, maximizing space use
Bush Beans
Fix nitrogen in soil that corn can utilize, while corn provides natural support
Pole Beans
Climb corn stalks for support while fixing nitrogen to benefit corn growth
Summer Squash
Large leaves provide ground cover to retain moisture and suppress weeds
Nasturtiums
Attract beneficial insects and repel cucumber beetles and corn earworms
Marigolds
Deter corn earworms, aphids, and nematodes with their strong scent
Dill
Attracts beneficial predatory insects that control corn pests like aphids
Sunflowers
Attract pollinators and beneficial insects while providing windbreak protection
Keep Apart
Black Walnut
Releases juglone toxin that severely stunts corn growth and development
Fennel
Inhibits corn growth through allelopathic compounds released by roots
Brassicas
Compete heavily for nitrogen and can stunt corn growth in early stages
Tomatoes
Both are heavy nitrogen feeders creating intense competition for nutrients
Pests & Disease Resistance
Resistance
Good resistance to northern corn leaf blight and rust
Common Pests
Corn earworm, European corn borer, corn rootworm, raccoons
Diseases
Southern corn leaf blight, common smut, corn rust