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.

You will be able to determine when to plant helianthemum by checking out the USDA zone info for Litchfield.

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 tells us that you can get them planted earlier than other frost tender plants.

The earliest that you can plant helianthemum in Litchfield 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. If you wait any later than that and 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

In Litchfield the average date of last frost happens on May 15. In the coldest months of winter you should expect an average low temperature of -25°F.

Always keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for Litchfield and it is different every year. Since half of the time in Litchfield last frost occurs after May 15 be ready to protect your helianthemum in the event of one of those late frosts.

USDA Zone Info for Litchfield

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Litchfield

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