When can I plant Dahlia in Zone 6a

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

In Zone 6a you can determine when to plant dahlia by using the USDA zone info.


Planting Calendar for Dahlia

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

You can not plant dahlia until after the last frost because they require warm weather.

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

The earliest that you can plant dahlia 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 dahlia and expect a good harvest is probably August. If you wait any later than that and your dahlia may not have a chance to grow to maturity. If you are starting your dahlia indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

In Zone 6a the average date of last frost happens on April 15. We can expect an average low temperature of -10°F in the coldest months of winter.

Since the USDA zone info for Zone 6a is not always accurate our actual date of last frost is different every year. Since half of the time in Zone 6a it frosts late in the year after April 15 be ready to cover your dahlia if we have one of those late frosts.

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.