The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

It's a good idea to estimate when it's the best time to plant sunflowers by reviewing the USDA zone info for Knoxville.

Planting Calendar for Sunflowers

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

You really shouldn't plant sunflowers until after the last frost has passed because they are not cold tolerant.

The earliest that you can plant sunflowers in Knoxville 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. Any later than that and your sunflowers may not have a chance to grow to maturity. Starting your sunflowers indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Knoxville. You should expect an average low temperature of -15°F in the coldest months of winter.

Keep in mind that USDA zone info for Knoxville is just an average and the actual date of last frost changes from year to year. Since half of the time in Knoxville last frost occurs after April 15 be ready to cover your sunflowers in the event of a late frost.

USDA Zone Info for Knoxville

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 Knoxville

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