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.

You can figure out when it's possible to plant helianthemum in Merrill by checking out the USDA zone info.

Planting Calendar for Helianthemum

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

Since helianthemum are one of those plants that can tolerate a little bit of cold weather you can plant them a little bit earlier in the year than more sensitive plants.

The earliest that you can plant helianthemum in Merrill 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. You probably don't want to wait any later than that or else your helianthemum may not have a chance to really do well. If you are starting your helianthemum indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

The average date of last frost is May 15 in Merrill. You can expect an average low temperature of -30°F in the coldest months of winter.

Keep in mind that USDA zone info for Merrill is not always accurate and the actual date of last frost can change quite a bit from year to year. Since half of the time in Merrill it frosts late in the year after May 15 be ready to protect your helianthemum in the event of one of those late frosts.

USDA Zone Info for Merrill

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 Merrill

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