Planting Timeline
Showing dates for Silver King in USDA Zone 7
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Silver King · Zones 3–9
Growing Details
Zone-by-Zone Planting Calendar
Complete Growing Guide
Silver King thrives in rich, well-amended soil with excellent drainage. Before planting, work 2-3 inches of aged compost or well-rotted manure into your planting area, along with a balanced granular fertilizer (10-10-10) at 2 pounds per 100 square feet. This heavy feeder needs nutrient-dense soil from day one.
Direct sow Silver King after soil temperatures consistently reach 60°F and nighttime temperatures stay above 50°F. Plant seeds 1 inch deep and 4-6 inches apart in rows spaced 30-36 inches apart. For optimal pollination, plant in blocks of at least four rows rather than single long rows – corn is wind-pollinated and needs neighbors for proper kernel development. Thin seedlings to 8-12 inches apart once they reach 4 inches tall.
Side-dress with nitrogen-rich fertilizer when plants reach knee-high (about 18 inches), applying compost or blood meal in a shallow trench 6 inches from the base of each stalk. Repeat this feeding when silks first appear. Silver King's vigorous growth demands consistent nutrition throughout its 85-90 day growing period.
Maintain steady soil moisture of 1-1.5 inches weekly, especially during tasseling and silk emergence. Water at soil level to avoid wetting foliage, which can promote fungal diseases. Mulch heavily around plants to retain moisture and suppress weeds, keeping mulch 3 inches away from stalks to prevent pest harboring.
Avoid common mistakes like planting too early in cool soil (leads to poor germination), shallow cultivation near plants (damages shallow roots), and irregular watering during ear development (causes poor kernel fill). Hill soil around the base of stalks when they're 12 inches tall to improve stability and root development. In windy areas, consider planting your Silver King block near a fence or taller plants for protection, as the large ears can make stalks top-heavy.
Harvesting
Harvest Silver King when silks turn brown and dry but husks remain bright green – typically 85-90 days from planting. The key test is the fingernail puncture: kernels should release milky juice when pressed, not clear liquid (underripe) or thick paste (overripe). Ears should feel firm and full from tip to base with no gaps between kernels.
Pull back a small section of husk to check kernel development – they should be plump, milky-white, and arranged in tight, straight rows. The milk stage is crucial for Silver King's signature sweetness and tender texture. Harvest in early morning when sugar content peaks and ears are cool. Twist ears sharply downward while pulling away from the stalk, or cut the stem with a sharp knife 1 inch below the ear. Each stalk typically produces 1-2 harvestable ears. Once ears reach peak ripeness, you have a 3-5 day window before kernels begin converting sugars to starch and lose their tender texture.
Storage & Preservation
Fresh Silver King corn deteriorates rapidly as sugars convert to starch. For immediate use within 1-2 days, store unhusked ears in the refrigerator at 32-35°F with high humidity – wrap in damp paper towels and place in perforated plastic bags. For longer storage, husk and blanch whole ears in boiling water for 7-9 minutes depending on ear size, then plunge into ice water. Cut kernels from cobs and freeze in portion-sized containers for up to 12 months. Silver King's firm kernels also excel for pressure canning – process pint jars of cut kernels at 11 pounds pressure for 55 minutes. The variety's excellent kernel retention makes it ideal for whole-ear freezing after blanching, maintaining texture better than many modern hybrids when thawed.
History & Origin
Silver King emerged in the 1950s as an open-pollinated white sweet corn developed for reliable production and exceptional eating quality. This American heirloom variety was bred during the post-war era when home gardeners sought dependable varieties that could match commercial quality while maintaining the genetic stability of open-pollinated seeds.
The variety gained popularity throughout the Midwest and Northeast, becoming a staple in seed catalogs by the 1960s. Silver King represented the pinnacle of standard sweet corn breeding before the introduction of supersweet and synergistic varieties in later decades. Its development focused on combining the classic corn flavor that American families craved with improved ear fill, disease resistance, and consistent performance across various growing conditions.
Unlike many modern hybrids, Silver King allows gardeners to save seeds year after year, maintaining its genetic integrity and local adaptation. This variety became particularly valued in areas with shorter growing seasons due to its reliable maturity and vigorous growth habit, earning its place as a trusted heirloom for serious corn growers.
Advantages
- +Exceptional ear fill with minimal tip gaps, even in challenging weather
- +True heirloom genetics allow seed saving for improved local adaptation over time
- +Outstanding kernel retention when freezing – maintains texture better than most varieties
- +Vigorous stalks with excellent lodging resistance in moderate winds
- +Reliable production of 1-2 full ears per stalk in most growing conditions
- +Stewart's wilt resistance provides security in areas where this disease is prevalent
- +Classic sweet corn flavor without the cloying sweetness of some modern hybrids
Considerations
- -85-90 day maturity makes it challenging for zones 3-4 without season extension
- -Susceptible to corn earworm damage in southern regions without intervention
- -Lower sugar content than modern supersweet varieties may disappoint some palates
- -Open-pollinated nature means potential cross-pollination if other corn varieties grown nearby
Companion Plants
Plant Together
Beans
Fix nitrogen in soil that corn needs, corn provides natural trellis support
Squash
Ground cover suppresses weeds, retains soil moisture, part of Three Sisters planting
Marigolds
Repel corn earworm, aphids, and nematodes with natural compounds
Nasturtiums
Trap crop for aphids and cucumber beetles, attract beneficial predatory insects
Dill
Attracts beneficial wasps and ladybugs that control corn borers and aphids
Sunflowers
Attract beneficial insects and birds, provide windbreak protection
Basil
Repels thrips and aphids, may enhance corn growth through root interactions
Parsley
Attracts beneficial insects like hoverflies that prey on corn pests
Keep Apart
Tomatoes
Both heavy nitrogen feeders creating competition, corn can shade tomatoes excessively
Black Walnut
Releases juglone toxin that inhibits corn germination and stunts growth
Fennel
Allelopathic compounds inhibit corn growth and development
Pests & Disease Resistance
Resistance
Good general disease tolerance, resistant to Stewart's wilt
Common Pests
Corn earworm, European corn borer, corn rootworm, cutworms
Diseases
Common rust, northern corn leaf blight, smut