One of the first steps you take when you are estimating your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The best time to plant cosmos in Alpharetta should 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.

Cosmos are barely cold tolerant which tells us that you can plant them slightly earlier than plants that are more sensitive to the cold.

The earliest that you can plant cosmos in Alpharetta 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. If you wait any later than that and your cosmos may not have a chance to grow to maturity. You can get started a little bit earlier by starting your cosmos indoors.

Last Frost Date

In Alpharetta the average date of last frost happens on April 15. In the coldest months of winter you can expect an average low temperature of 5°F.

Since the USDA zone info for Alpharetta is an average the actual date of last frost changes from year to year. Half of the time in Alpharetta you get a frost after April 15 so make sure that you are ready to cover your cosmos if you have one of those late frosts.

USDA Zone Info for Alpharetta

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 Alpharetta

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