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

The first chance to plant dahlia in Havre should be estimated by checking out the USDA zone info.

Planting Calendar for Dahlia

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

Dahlia require warm weather which means that you have to wait until it warms up after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant dahlia in Havre 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. Any later than that and your dahlia may not have a chance to grow to maturity. Starting your dahlia indoors is a great way to get them started a little bit earlier.

Last Frost Date

The average date of last frost is May 15 in Havre. It might get as low as -30°F during the coldest months of winter.

Always keep in mind that USDA zone info for Havre is an average and the actual date of last frost changes from year to year. Since half of the time in Havre you get a frost after May 15 be ready to cover your dahlia in the event of one of those late frosts.

USDA Zone Info for Havre

Here is the info for USDA Zone 4a.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-30°F
Highest Expected Low	-25°F

This means that on a really cold year, the coldest it will get is -30°F. On most years you should be prepared to experience lows near -25°F.

Plants to Grow in Havre

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