The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By looking at the USDA zone info for Crookston it's possible to estimate when you can plant hardy asters.

Planting Calendar for Hardy Asters

Frost tolerance for hardy asters:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Since hardy asters are barely cold tolerant you can plant them slightly earlier in the year than more sensitive plants.

The earliest that you can plant hardy asters in Crookston 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 hardy asters and expect a good harvest is probably August. You probably don't want to wait any later than that or else your hardy asters may not have a chance to grow to maturity. You can get started a few weeks earlier by starting your hardy asters indoors.

Last Frost Date

The average date of last frost is May 15 in Crookston. In the coldest months of winter you should expect an average low temperature of -30°F.

Always keep in mind that USDA zone info for Crookston is an average and the actual date of last frost will vary from year to year. Half of the time in Crookston it frosts late in the year after May 15 so be sure to be ready to protect your hardy asters in the event of a surprise late frost.

USDA Zone Info for Crookston

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 Crookston

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