One of the first steps you take when you are determining your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In Fergus Falls you can estimate when it's the best time to plant dahlia by looking at 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.

It's probably a bad idea to plant dahlia until after the last frost when the weather gets warmer because they are not cold tolerant.

The earliest that you can plant dahlia in Fergus Falls 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. You probably don't want to wait any later than that or else 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 few weeks earlier.

Last Frost Date

In Fergus Falls the average date of last frost happens on May 15. You should expect an average low temperature of -30°F in the coldest months of winter.

Since the USDA zone info for Fergus Falls is not always accurate the actual date of last frost changes from year to year. Half of the time in Fergus Falls there is a last frost after May 15 so just be sure to be ready to protect your dahlia if you have a surprise late frost.

USDA Zone Info for Fergus Falls

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 Fergus Falls

You may be interested in your other planting guides for Fergus Falls.