When to Plant Dahlia in Zone 3b

The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You can figure out when to plant dahlia in Zone 3b by looking at the USDA zone info.


Planting Calendar for Dahlia

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

It's probably not a good idea to plant dahlia until after all chance of frost has passed 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 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 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 little bit earlier.

Last Frost Date

On average all chance of frost has passed is on May 15 in Zone 3b. In the coldest months of winter you can expect an average low temperature of -35°F.

Since the USDA zone info for Zone 3b is not always accurate the actual date of last frost will vary from year to year. Half of the time in Zone 3b there is a last frost after May 15 so be sure to be ready to cover your dahlia if you have 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 your other planting guides for Zone 3b.