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

By checking out the USDA zone info for Crookston you will be able to determine when it's possible to plant helianthemum.

Planting Calendar for Helianthemum

Frost tolerance for helianthemum:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Helianthemum do well in moderate cold which means that you can get them planted earlier than plants that are more sensitive to the cold.

The earliest that you can plant helianthemum in Crookston is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant helianthemum and expect a good harvest is probably August. Any later than that and your helianthemum may not have a chance to fully mature. Starting your helianthemum indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

In Crookston the average date of last frost happens on May 15. It might get as low as -30°F during the coldest months of winter.

Since the USDA zone info for Crookston is an average the actual date of last frost is different every year. Since half of the time in Crookston you get surprised by a frost after May 15 be ready to cover your helianthemum in the event of one of those late frosts.

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.