When can I plant Dahlias in Zone 6a

The USDA Zone info is a great tool for gardeners to help us figure out our gardening schedule. 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 getting a good idea when to plant dahlias is to check out the USDA zone info for Zone 6a.


Planting Calendar for Dahlias

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

You really shouldn't plant dahlias until after all chance of frost has passed because they do not do well in cold weather.

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 6a 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. Any later than that and your dahlias may not have a chance to grow to maturity. You can get started a little bit earlier by starting your dahlias indoors.

Last Frost Date

The average date of last frost is April 15 in Zone 6a. We should expect an average low temperature of -10°F in the coldest months of winter.

Remember that our actual date of last frost is just an average because it is based on the USDA zone info for Zone 6a and it will vary from year to year. Since half of the time in Zone 6a last frost occurs after April 15 be ready to cover your dahlias if we have a surprise late frost.

USDA Zone Info for Zone 6a

Here is the info for USDA Zone 6a.

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

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

Plants to Grow in Zone 6a

You may be interested in our other planting guides for Zone 6a.