When can I plant Dahlias in Zone 3b

Before planting it is a good idea to find our USDA Zone info to estimate our garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for our area.

You can determine when it's possible to plant dahlias in Zone 3b by using the USDA zone info.


Planting Calendar for Dahlias

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

Dahlias do not do well in cold weather which tells us that you must wait until it warms up after the last frost when the weather gets warmer 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 3b is May. However, you really should wait until June 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 couple of weeks earlier by starting your dahlias indoors.

Last Frost Date

The average date of last frost is May 15 in Zone 3b. We can expect an average low temperature of -35°F in the coldest months of winter.

Since the USDA zone info for Zone 3b is an average our actual date of last frost can change quite a bit from year to year. Since half of the time in Zone 3b we get surprised by a frost after May 15 be ready to protect your dahlias in the event of a surprise late frost.

USDA Zone Info for Zone 3b

Here is the info for USDA Zone 3b.

Average Date of Last Frost (spring)May 15
Average Date of First Frost (fall)September 15
Lowest Expected Low-35°F
Highest Expected Low-30°F

This means that on a really cold year, the coldest it will get is -35°F. On most years you should be prepared to experience lows near -30°F.

Plants to Grow in Zone 3b

You may be interested in our other planting guides for Zone 3b.