Growing Corn in Containers: Depth, Pollination, and Feeding

A gardener asks how deep to plant corn in containers.

Planting Depth and Container Requirements

• Depth: 1 inch deep in warm soil (60°F+).
• Container: Minimum 12 inches deep, 18+ inches wide (5+ gallons) per 3–4 plants.
• Spacing: 8–12 inches apart in a block (not rows) for wind pollination.

Critical: Plant in Blocks for Pollination

Corn is wind-pollinated. Each silk must catch pollen from tassels. In containers, plant at least 9–12 plants in a tight grid (3×3 or 3×4) to ensure kernel set. Single rows or few plants yield poorly filled ears.

Heavy Feeding Regimen

Corn is a nitrogen glutton. In containers:

1. At planting: Mix slow-release fertilizer (e.g., 10-10-10) into soil.
2. When plants are 12 inches tall: Side-dress with high-nitrogen fertilizer (blood meal, fish emulsion, or 20-10-10).
3. When tassels appear: Repeat nitrogen feed.
4. Water consistently—never let soil dry more than 2 inches deep.

Best Varieties for Containers

• 'On Deck' (bred for containers, 4–5 ft, 2 ears/plant)
• 'Golden Bantam' (heirloom, 5 ft, good flavor)
• 'Kandy Korn' (SE type, sweet, 7 ft—needs large pot)

Harvest Tip

Ears are ready 3 weeks after silks appear, when silks brown and kernels exude milky juice when pierced.