One of the first steps you take when you are estimating 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.

The first chance to plant dahlias in Grand Forks can be figured out by referring to the USDA zone info.

Planting Calendar for Dahlias

Frost tolerance for dahlias:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

You can not plant dahlias until after the last frost when the weather gets warmer because they require warm weather.

The earliest that you can plant dahlias in Grand Forks 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 dahlias and expect a good harvest is probably August. Any later than that and your dahlias may not have a chance to really do well. Starting your dahlias indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

In Grand Forks 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.

Keep in mind that USDA zone info for Grand Forks may not be accurate from year to year and the actual date of last frost is different every year. Since half of the time in Grand Forks you get a frost after May 15 be ready to cover your dahlias if you have a late frost.

USDA Zone Info for Grand Forks

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 Grand Forks

You may be interested in your other planting guides for Grand Forks.