One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The earliest that you can plant cosmos in Raleigh can be figured out by looking at the USDA zone info.

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 Raleigh 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. Any later than that and your cosmos may not have a chance to grow to maturity. Starting your cosmos indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Raleigh. In the coldest months of winter you should expect an average low temperature of 5°F.

Since the USDA zone info for Raleigh is not always accurate the actual date of last frost will vary from year to year. Since half of the time in Raleigh you get surprised by a frost after April 15 be ready to cover your cosmos in the event of a late frost.

USDA Zone Info for Raleigh

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 Raleigh

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