When to Plant Dahlias in Zone 1b

One of the first steps you take when you are figuring out your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

It's possible to estimate when to plant dahlias by reviewing the USDA zone info for Zone 1b.


Planting Calendar for Dahlias

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

Dahlias are not cold tolerant which means 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 1b 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 dahlias and expect a good harvest is probably July. You probably don't want to wait any later than that or else your dahlias may not have a chance to really do well. Starting your dahlias indoors is a great way to get them started a few weeks earlier.

Last Frost Date

In Zone 1b the average date of last frost happens on June 15. It might get as low as -55°F during the coldest months of winter.

Since the USDA zone info for Zone 1b is not always accurate the actual date of last frost will vary from year to year. Half of the time in Zone 1b there is a last frost after June 15 so always be ready to cover your dahlias in the event of a surprise late frost.

USDA Zone Info for Zone 1b

Here is the info for USDA Zone 1b.

Average Date of Last Frost (spring)June 15
Average Date of First Frost (fall)July 15
Lowest Expected Low-55°F
Highest Expected Low-50°F

This means that on a really cold year, the coldest it will get is -55°F. On most years you should be prepared to experience lows near -50°F.

Plants to Grow in Zone 1b

You may be interested in your other planting guides for Zone 1b.