When can I plant Dahlias in Zone 8b

One of the best tools that we have as gardeners to help us estimate our gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for our area.

A way of estimating when it's a good idea to plant dahlias is to refer to the USDA zone info for Zone 8b.


Planting Calendar for Dahlias

Frost tolerance for dahlias: Not tolerant of frost.
When you should plant them: After the last frost.

Dahlias are not cold tolerant which tells us that it's important to wait until it warms up after the last frost before you can plant them.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant dahlias
Possibly ok, but a risky time to plant dahlias
Probably not a good time to plant dahlias

The earliest that you can plant dahlias in Zone 8b 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. Starting your dahlias indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on March 15 in Zone 8b. We should expect an average low temperature of 15°F in the coldest months of winter.

Since the USDA zone info for Zone 8b may not be accurate from year to year our actual date of last frost will vary from year to year. Half of the time in Zone 8b we get a frost after March 15 so make sure that you are ready to cover your dahlias if we have a late frost.

USDA Zone Info for Zone 8b

Here is the info for USDA Zone 8b.

Average Date of Last Frost (spring)March 15
Average Date of First Frost (fall)November 15
Lowest Expected Low15°F
Highest Expected Low20°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 20°F.

Plants to Grow in Zone 8b

You may be interested in our other planting guides for Zone 8b.