When to Plant Dahlia in Polson, MT

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.

It's a good idea to estimate when it's a good idea to plant dahlia by reviewing the USDA zone info for Polson.


Planting Calendar for Dahlia

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

Dahlia are not cold tolerant which tells us that it is important to wait until it warms up after all chance of frost has passed 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 Polson 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. If you wait any later than that and your dahlia may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your dahlia indoors.

Last Frost Date

The average date of last frost is April 15 in Polson. You should expect an average low temperature of -10°F in the coldest months of winter.

Keep in mind that USDA zone info for Polson is just an average and the actual date of last frost can change quite a bit from year to year. Since half of the time in Polson there is a last frost after April 15 be ready to cover your dahlia if you have a late frost.

USDA Zone Info for Polson

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)April 15
Average Date of First Frost (fall)October 15
Lowest Expected Low-10°F
Highest Expected Low-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Polson

You may be interested in your other planting guides for Polson.