When to Plant Corn in Southern California

Significance

• Whether corn is fully grown with maturing kernels or is recently emerged from the soil, it is a warm-season crop that cannot tolerate frost. To ensure you do not waste the time spent tending to your crop, plant to avoid both spring and fall frost dates.

Considerations

• Gardeners often use a rule of thumb for planting corn: plant no sooner than two weeks before the final expected frost of the spring. Seeds require approximately 11 days underground for germination and growth before emerging, allowing most seeds to avoid frost exposure while beginning the growth process. Late corn crops must be planted an average of 110 days before the first expected frost of fall to mature before autumn frost occurs.

Expert Insight

• Farm advisors with the University of California Cooperative Extension service, recommend planting sweet corn between the months of March and July for spring, mid and fall season crops. They warn that exact planting dates vary among small sections of the state and advise planting only after soil temperatures reach a minimum of 55 degrees Fahrenheit, which can occur as early as January in southern desert valleys.