When can I plant Dahlia in Zone 5b

Before planting it is a good idea to find our USDA Zone info to estimate our garden schedule. 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 5b should be estimated by reviewing 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.

Dahlia require warm weather which means that it is necessary to wait until it warms up after the last frost before you can plant them.

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 5b 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. Any later than that and your dahlia may not have a chance to really do well. 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 the last frost is on April 15 in Zone 5b. It might get as low as -15°F during the coldest months of winter.

It's important to remember that our actual date of last frost is an average because it is based on the USDA zone info for Zone 5b and it changes from year to year. Since half of the time in Zone 5b there is a last frost after April 15 be ready to protect your dahlia if we have a surprise late frost.

USDA Zone Info for Zone 5b

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)April 15
Average Date of First Frost (fall)October 15
Lowest Expected Low-15°F
Highest Expected Low-10°F

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Zone 5b

You may be interested in our other planting guides for Zone 5b.