The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

A common way of estimating when it's the best time to plant sunflowers is to refer to the USDA zone info for Carbondale.

Planting Calendar for Sunflowers

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

Since sunflowers require warm weather it is important to wait until after the last frost has passed before you can plant them.

The earliest that you can plant sunflowers in Carbondale 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. Starting your sunflowers indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average all chance of frost has passed is on April 15 in Carbondale. You should expect an average low temperature of -15°F in the coldest months of winter.

Remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Carbondale and it changes from year to year. Half of the time in Carbondale it frosts late in the year after April 15 so make sure that you are ready to cover your sunflowers in the event of a surprise late frost.

USDA Zone Info for Carbondale

Here is the info for USDA Zone 5b.

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

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Carbondale

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