Planting guide · zone 9a
When to plant sweet corn in zone 9a
In zone 9a, the average last spring frost is Feb 28 and the first fall frost is Dec 1. Here is sweet corn's whole year, counted from those dates.
Mar 7Direct sowSpring
Mar 21Succession sowing 2Spring
Apr 4Succession sowing 3Spring
J
F
M
A
M
J
J
A
S
O
N
D
Soil & site
The heaviest nitrogen feeder in the garden — rich soil, side-dress when knee-high.
Seedling care
Direct sow in warm soil; cold ground gives patchy stands.
Growing notes
Plant in blocks of at least 4 short rows, never one long row — corn is wind-pollinated and needs neighbors on all sides for full ears.
Harvest
When silks are brown and dry, pierce a kernel: milky juice means ready. Roughly 20 days after silks first appear.