One of the first steps you take when you are estimating your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The USDA zone info for Siler City can be used to figure out when to plant cosmos.

Planting Calendar for Cosmos

Frost tolerance for cosmos:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Since cosmos do ok in moderate cold you can plant them slightly earlier in the year than more sensitive plants.

The earliest that you can plant cosmos in Siler City is March. However, you really should wait until April if you don't want to take any chances.

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

Last Frost Date

The average date of last frost is April 15 in Siler City. You should expect an average low temperature of 5°F in the coldest months of winter.

Since the USDA zone info for Siler City is an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Siler City there is a last frost after April 15 be ready to protect your cosmos if you have one of those late frosts.

USDA Zone Info for Siler City

Here is the info for USDA Zone 7b.

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

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

Plants to Grow in Siler City

You may be interested in your other planting guides for Siler City.