One of the first steps you take when you are determining your gardening schedule is find your USDA Zone info. 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 figure out when it's possible to plant helianthemum by checking out the USDA zone info for Greenbrier.

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 start planting them earlier than other frost tender plants.

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

The last month that you can plant helianthemum and expect a good harvest is probably September. Any later than that and your helianthemum may not have a chance to really do well. Starting your helianthemum indoors is a great way to get them started a few weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Greenbrier. In the coldest months of winter you can expect an average low temperature of 5°F.

Remember that USDA zone info for Greenbrier is an average and the actual date of last frost can change quite a bit from year to year. Since half of the time in Greenbrier you get a frost after April 15 be ready to cover your helianthemum in the event of a late frost.

USDA Zone Info for Greenbrier

Here is the info for USDA Zone 7b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	5°F
Highest Expected Low	10°F

This means that on a really cold year, the coldest it will get is 5°F. On most years you should be prepared to experience lows near 10°F.

Plants to Grow in Greenbrier

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