Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Fort Collins can be reviewed to determine when it's a good idea to plant sunflowers.

Planting Calendar for Sunflowers

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

Since sunflowers do not do well in cold weather you need to wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant sunflowers in Fort Collins 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. If you wait any later than that and your sunflowers may not have a chance to fully mature. You can get started a little bit earlier by starting your sunflowers indoors.

Last Frost Date

The average date of last frost is April 15 in Fort Collins. It might get as low as -15°F during the coldest months of winter.

Always keep in mind that the actual date of last frost is not always accurate because it is based on the USDA zone info for Fort Collins and it can change quite a bit from year to year. Since half of the time in Fort Collins it frosts late in the year after April 15 be ready to cover your sunflowers if you have a surprise late frost.

USDA Zone Info for Fort Collins

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 Fort Collins

You may be interested in your other planting guides for Fort Collins.