One of the first steps you take when you are getting a good idea 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 USDA zone info for Alpharetta can be used to estimate when it's a good idea to plant dahlias.

Planting Calendar for Dahlias

Frost tolerance for dahlias:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

You can not plant dahlias until after all chance of frost has passed because they are not cold tolerant.

The earliest that you can plant dahlias in Alpharetta 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 dahlias and expect a good harvest is probably August. You probably don't want to wait any later than that or else your dahlias may not have a chance to grow to maturity. If you are starting your dahlias indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

In Alpharetta the average date of last frost happens on April 15. It might get as low as 5°F during the coldest months of winter.

Just be sure to remember that USDA zone info for Alpharetta is not always accurate and the actual date of last frost changes from year to year. Half of the time in Alpharetta last frost occurs after April 15 so always be ready to cover your dahlias if you have a late frost.

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.