When to Plant Sunflowers in Edwardsville, IL

Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The earliest that you can plant sunflowers in Edwardsville can be figured out by reviewing the USDA zone info.


Planting Calendar for Sunflowers

Frost tolerance for sunflowers: Not tolerant of frost.
When to plant: After the last frost.

Since sunflowers are not cold tolerant you need to wait until after all chance of frost has passed before you can plant them.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant sunflowers
Possibly ok, but a risky time to plant sunflowers
Probably not a good time to plant sunflowers

The earliest that you can plant sunflowers in Edwardsville is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant sunflowers and expect a good harvest is probably August. You probably don't want to wait any later than that or else your sunflowers may not have a chance to fully mature. You can get started a few weeks earlier by starting your sunflowers indoors.

Last Frost Date

On average all chance of frost has passed is on April 15 in Edwardsville. In the coldest months of winter you can expect an average low temperature of -10°F.

Remember that the actual date of last frost is an average because it is based on the USDA zone info for Edwardsville and it changes from year to year. Since half of the time in Edwardsville last frost occurs after April 15 be ready to protect your sunflowers in the event of a late frost.

USDA Zone Info for Edwardsville

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)April 15
Average Date of First Frost (fall)October 15
Lowest Expected Low-10°F
Highest Expected Low-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Edwardsville

You may be interested in your other planting guides for Edwardsville.