One of the first steps you take when you are estimating your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

One way of getting a good idea when to plant sunflowers is to look at the USDA zone info for Collinsville.

Planting Calendar for Sunflowers

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

You should not plant sunflowers until after the last frost because they require warm weather.

The earliest that you can plant sunflowers in Collinsville 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 grow to maturity. You can get started a little bit earlier by starting your sunflowers indoors.

Last Frost Date

On average the last frost has passed is on April 15 in Collinsville. It might get as low as 0°F during the coldest months of winter.

Always keep in mind that USDA zone info for Collinsville is not always accurate and the actual date of last frost changes from year to year. Since half of the time in Collinsville you get a frost after April 15 be ready to protect your sunflowers if you have one of those late frosts.

USDA Zone Info for Collinsville

Here is the info for USDA Zone 7a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	0°F
Highest Expected Low	5°F

This means that on a really cold year, the coldest it will get is 0°F. On most years you should be prepared to experience lows near 5°F.

Plants to Grow in Collinsville

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