Sugar Dots
Zea mays 'Sugar Dots'
A unique and eye-catching bicolor corn that produces stunning ears with purple and white kernels creating a polka-dotted appearance. This synergistic variety combines the visual appeal of ornamental corn with genuine sweet corn eating quality, making it perfect for gardeners who want something truly special. The purple kernels add antioxidants while maintaining excellent flavor and tenderness.
Harvest
78-85d
Days to harvest
Sun
Full sun
Zones
2–11
USDA hardiness
Height
5-8 feet
Planting Timeline
Showing dates for Sugar Dots in USDA Zone 7
All Zone 7 corn →Zone Map
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Sugar Dots · Zones 2–11
Growing Details
Zone-by-Zone Planting Calendar
| Zone | Indoor Start | Transplant | Direct Sow | Harvest |
|---|---|---|---|---|
| Zone 1 | — | — | July – August | October – August |
| Zone 2 | — | — | June – August | October – September |
| Zone 11 | — | — | January – March | May – June |
| Zone 12 | — | — | January – March | May – June |
| Zone 13 | — | — | January – March | May – June |
| Zone 3 | — | — | June – July | September – October |
| Zone 4 | — | — | June – July | September – October |
| Zone 5 | — | — | May – June | September – October |
| Zone 6 | — | — | May – June | August – October |
| Zone 7 | — | — | April – June | August – September |
| Zone 8 | — | — | April – May | July – September |
| Zone 9 | — | — | March – April | June – August |
| Zone 10 | — | — | February – April | June – July |
Succession Planting
For a longer harvest window, direct sow Sugar Dots every 14 days from mid-April through mid-June in zone 7, once soil temps hit 65°F (germination stalls below 60°F and you'll get the seed-corn maggot problem NC State warns about). Stop succession plantings about 90 days before your first expected fall frost so the last block has time to finish — 78-85 days to harvest plus a buffer for cool September nights slowing things down.
If you're tight on space, two plantings three weeks apart is usually enough — block-plant each succession at least 4 rows wide for pollination, because a single long row pollinates poorly and you'll get gappy ears.
Complete Growing Guide
Sugar Dots requires consistent warm soil (at least 65°F) for reliable germination, so delaying planting until late spring prevents the seed rot common in cool, damp conditions that this bicolor variety experiences more readily than standard yellow corn. Plant in full sun with rich, well-draining soil amended with compost, as the dual pigmentation demands robust nutrition. Watch for corn earworm pressure on the silk and tip areas—the exposed purple kernels attract slightly more attention from pests than solid-colored varieties, making regular scouting essential. This cultivar maintains moderate height at 5-8 feet, eliminating excessive lodging concerns, but thin seedlings to 8-10 inches apart for proper air circulation around the developing bicolor ears. For maximum kernel tenderness and that distinctive berry-flavored sweetness, harvest when kernels are still milky; waiting too long causes the purple color to deepen but texture to toughen, diminishing the sweet eating experience that justifies this variety's moderate growing difficulty.
Light: Full sun (6 or more hours of direct sunlight a day). Soil: Clay, High Organic Matter, Loam (Silt). Soil pH: Acid (<6.0), Neutral (6.0-8.0). Drainage: Good Drainage. Height: 5 ft. 0 in. - 8 ft. 0 in.. Spread: 1 ft. 0 in. - 2 ft. 0 in.. Spacing: 12 inches-3 feet. Growth rate: Rapid. Maintenance: Medium. Propagation: Seed. Regions: Coastal, Mountains, Piedmont.
Harvesting
Harvest Sugar Dots when the husks turn from green to pale brown and the silk at the tip browns and dries completely, which typically occurs around 78–85 days after planting. Gently peel back a small section of husk to confirm the kernels have filled out fully and the purple and white polka-dot pattern is vivid and distinct. The ear should feel firm and slightly plump when squeezed gently through the husk. Unlike single-harvest varieties, Sugar Dots produces multiple ears per stalk and will continue producing throughout the season if you harvest regularly, encouraging the plant to set additional ears. Pick ears in the early morning when sugars are at their peak, twisting and pulling downward sharply to cleanly detach them from the stalk.
Color: Gold/Yellow. Type: Caryopsis. Length: > 3 inches. Width: 1-3 inches.
Garden value: Edible, Showy
Harvest time: Fall
Edibility: Edibile
Storage & Preservation
Fresh Sugar Dots corn should be used within 24-48 hours of harvest for peak sweetness and tenderness. Store unhusked ears in the refrigerator at 32-35°F with high humidity—wrap loosely in damp paper towels and place in perforated plastic bags. Never store at room temperature as sugars convert to starch rapidly.
For freezing, blanch whole kernels in boiling water for 4 minutes, then plunge into ice water. Cut kernels from cobs and freeze in portion-sized containers for up to 12 months. Alternatively, freeze whole ears after blanching for 6-8 minutes. The purple kernels retain their color and antioxidant properties through freezing.
Dehydrating works exceptionally well with Sugar Dots—the contrasting colors create striking dried corn for decorative and culinary uses. Dry at 135°F for 8-12 hours until kernels are completely moisture-free. Store dried kernels in airtight containers for grinding into cornmeal or rehydrating for soups and stews.
History & Origin
While specific breeder attribution and introduction year for Sugar Dots remain undocumented in readily available sources, this variety appears to represent a modern crossing between ornamental polka-dot corn lines and sweet corn germplasm, likely developed within the specialty seed trade during the early 2000s. The variety embodies a contemporary breeding trend toward visually distinctive vegetables that maintain culinary utility, drawing on decades of work with purple corn anthocyanins and the established sweet corn breeding infrastructure. Its development reflects grower and gardener demand for novelty corn varieties that transcend pure ornamental appeal while retaining genuine eating quality.
Origin: Mexico
Advantages
- +Stunning purple and white polka-dot kernels create exceptional visual garden interest
- +Combines ornamental appeal with genuinely sweet, tender eating quality
- +Purple kernels provide added antioxidants beyond standard sweet corn varieties
- +Medium maturity at 78-85 days fits well in most growing seasons
- +Subtle berry flavor notes from purple kernels offer unique taste experience
Considerations
- -Moderate growing difficulty requires more pest and disease management attention
- -High pest attraction from raccoons and corn earworms demands protective measures
- -Susceptible to multiple diseases including Northern corn leaf blight and Stewart's wilt
Companion Plants
The Three Sisters logic still holds with Sugar Dots. Beans climb the stalks (so you skip building a trellis) and fix nitrogen, which corn burns through fast — sweet corn is a heavy feeder. Squash sprawls underneath, shading the soil and keeping moisture even, which matters because Sugar Dots wants steady water through tasseling and silk. Sunflowers on the perimeter pull some of the same moths that target corn ears. Marigolds, nasturtiums, and sweet alyssum bring in hoverflies and parasitic wasps that help knock back corn earworm (Helicoverpa zea) and fall armyworm pressure. Dill does the same job once it flowers.
Keep tomatoes out of the corn block. Corn earworm and tomato fruitworm are the same insect (Helicoverpa zea) — putting the two crops side by side just doubles the breeding ground. Fennel is allelopathic to nearly everything and Sugar Dots is no exception; give it its own corner. Black walnut releases juglone from its roots, which corn handles poorly, so site the patch well outside the tree's root zone.
Plant Together
Beans
Fix nitrogen in soil that corn needs, corn provides natural trellis support
Squash
Large leaves suppress weeds and retain soil moisture, completes the Three Sisters guild
Marigolds
Repel corn earworms, aphids, and other harmful insects
Nasturtiums
Act as trap crop for aphids and cucumber beetles, repel squash bugs
Sunflowers
Attract beneficial insects and birds that eat corn pests, similar growing requirements
Dill
Attracts beneficial insects like parasitic wasps that control corn borers
Radishes
Break up soil compaction, mature quickly before corn needs space
Sweet Alyssum
Attracts beneficial insects and provides ground cover to retain moisture
Keep Apart
Tomatoes
Both attract corn earworms, creating concentrated pest problems
Black Walnut
Produces juglone which is toxic to corn and inhibits growth
Fennel
Allelopathic properties inhibit corn germination and growth
Nutrition Facts
Per 100g serving. % Daily Value based on 2,000 calorie diet. Source: USDA FoodData Central (FDC #168538)
Pests & Disease Resistance
Resistance
Standard hybrid vigor with moderate disease resistance
Common Pests
Corn earworm, armyworm, corn rootworm, raccoons attracted to sweet kernels
Diseases
Northern corn leaf blight, common rust, Stewart's wilt
Troubleshooting Sugar Dots
What you'll see, why it happens, and what to do about it.
Ears with caterpillars chewing the tip kernels, frass visible under the husk at harvest
Likely Causes
- Corn earworm (Helicoverpa zea) — moths lay eggs on fresh silks, larvae feed down into the ear
- Unprotected silks during the 5-7 day pollination window
What to Do
- 1.Apply a few drops of mineral oil (or oil + Bt) to the silk channel 5-6 days after silks emerge — coats the silk and smothers young larvae
- 2.Trim off and trash the damaged ear tips at husking; the rest of the ear is fine to eat
- 3.Time plantings so silking doesn't peak with moth flights — UGA's Vegetable Garden Calendar references the Georgia Pest Management Handbook schedule for corn earworm timing
Ears with missing kernels in patches, sparse or gappy fill
Likely Causes
- Poor pollination from planting in a single long row instead of a block
- Heat stress above 95°F during tasseling, which kills pollen
- Inconsistent water during silking
What to Do
- 1.Plant in blocks of at least 4x4 rows, never a single row, so wind-blown pollen actually reaches silks
- 2.Hand-pollinate by snapping a tassel and shaking it over the silks in the morning if you've got a small patch
- 3.Water deeply (1-1.5 inches per week) from knee-high through silk-brown — this is non-negotiable for sweet corn
Orange-brown pustules on leaves that rub off on your fingers, lower leaves yellowing first
Likely Causes
- Common rust (Puccinia sorghi) — cool wet nights, especially in spring plantings
- Southern rust (Puccinia polysora) if pustules are smaller and concentrated on upper leaf surfaces — NC State's CDIN-002 covers this
What to Do
- 1.Space at the full 10-12 inches and don't crowd rows — airflow is the cheapest fungicide you have
- 2.Pull and trash heavily infected lower leaves; don't compost them
- 3.For next season, plant earlier so the crop finishes before late-summer rust pressure peaks
Frequently Asked Questions
How long does Sugar Dots corn take to grow from seed to harvest?▼
Can you grow Sugar Dots corn in containers?▼
What does Sugar Dots corn taste like compared to regular sweet corn?▼
Do I need to isolate Sugar Dots corn from other corn varieties?▼
Is Sugar Dots corn good for beginners to grow?▼
When should I plant Sugar Dots corn in my area?▼
Growing Guides from Wind River Greens
Where to Buy Seeds
Sources & References
External authority sources used in compiling this guide.
See the Methodology page for how this data is sourced, what's AI-assisted, and known limitations.