When can I plant Dahlia in Zone 1a

One of the first steps we take when we are determining our gardening schedule is find our 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.

The first chance to plant dahlia in Zone 1a should be determined by checking out 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 when the weather gets warmer.

You really shouldn't plant dahlia until after the last frost when the weather gets warmer 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 1a is June. However, you really should wait until July if you don't want to take any chances.

The last month that you can plant dahlia and expect a good harvest is probably July. You probably don't want to wait any later than that or else your dahlia may not have a chance to fully mature. You can get started a little bit earlier by starting your dahlia indoors.

Last Frost Date

On average all chance of frost has passed is on June 15 in Zone 1a. We can expect an average low temperature of -60°F in the coldest months of winter.

Since the USDA zone info for Zone 1a may not be accurate from year to year our actual date of last frost changes from year to year. Since half of the time in Zone 1a there is a last frost after June 15 be ready to cover your dahlia in the event of a surprise late frost.

USDA Zone Info for Zone 1a

Here is the info for USDA Zone 1a.

Average Date of Last Frost (spring)June 15
Average Date of First Frost (fall)July 15
Lowest Expected Low-60°F
Highest Expected Low-55°F

This means that on a really cold year, the coldest it will get is -60°F. On most years you should be prepared to experience lows near -55°F.

Plants to Grow in Zone 1a

You may be interested in our other planting guides for Zone 1a.