Crop lessons · Other crops
Growing Sweet corn in Florida
Zea mays var. rugosa · Poaceae (grass family)
Sweet corn is easy enough to grow if you have the room. Because the wind carries pollen from tassel to silk, plant it in a block of at least three rows rather than one long row, and grow only one type at a time so varieties do not cross. Corn earworm is the pest to scout for.1, 2
Planting1, 2
| How to start | seed |
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| Seed depth (inches) | 1 to 1½ (SP 103); Gardening Solutions gives 1 to 2 |
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| Spacing in the row (inches) | 6 to 8 (SP 103); Gardening Solutions gives 12 to 18 |
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| Between rows (inches) | 28 (SP 103); Gardening Solutions gives 24 to 36 |
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| Days to harvest | 65 to 90 (SP 103); Gardening Solutions says usually 60 to 90 |
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SP 103 planting dates: north Mar to Apr and Aug, central Jan to Apr, south Oct to Mar. Avoid poorly drained ground, where seed rots. Plants reach 6 to 8 feet or more, so site them where their shade will not fall on other crops.
Varieties UF/IFAS lists for Florida1, 2
- Silver Queen (white)
- How Sweet It Is (white)
- Sweet Ice (white)
- Sweet Riser (yellow)
- Early Sunglow (yellow)
Growing2, 1
| Sun | At least 6 to 8 hours of sun a day. |
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| Soil pH | 5.8 to 6.3 (SP 103's general target for vegetable gardens on sandy soil; no change is needed anywhere from 5.5 to 7.0). No crop-specific figure was found. |
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| Water | About 1 inch a week, wetting the soil about 6 inches deep; light sprinkles encourage shallow roots. Water in the morning so leaves dry before dark. Pollination and ear filling are the critical times. |
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| Fertilizer | Corn needs a lot of nitrogen to grow well (Gardening Solutions). General SP 103 advice: broadcast fertilizer at the label or soil-test rate just before planting, then make 2 or 3 light applications during the season just beyond the outer leaves. |
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Each plant has male tassels on top and female silks on the ears. In a small planting, help pollination by shaking a cut tassel over the silks or stripping pollen onto them. Removing suckers does not help.
Pests and diseases in Florida1, 3
- Corn earworm: SP 103 says to scout for it.
- Fall armyworm and other caterpillars, sap beetles, corn silk flies: Listed among sweet corn pests in the commercial Vegetable Production Handbook (CV135).
- Common rust and northern and southern corn leaf blight: Listed among sweet corn diseases in the same commercial handbook.
Harvest2, 1
Harvest when the kernels are full and tightly packed, usually 60 to 90 days after planting. Most ears on a planting ripen together, so stagger sowings for a longer season. Pick in the early morning to keep the sugar, and eat within a day or two.
In an aquaponics system
We haven't found a published source that covers sweet corn in aquaponics systems, so this lesson doesn't guess. The planting months above apply to a grow bed the same as to soil; the water does the watering.
What this lesson doesn't cover yet
- SP 103 and Gardening Solutions give different seed depth, in-row spacing and row spacing; both are shown.
- No crop-specific soil pH figure was found.
- Neither SRAC 454 nor the FAO aquaponics manual discusses corn.
Your county extension office and its Master Gardener volunteers can fill these in for your garden.