Before planting it is a good idea to find your USDA Zone info to figure out your garden 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 Piedmont it's a good idea to determine when 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 are moderately cold tolerant which tells us that you can start planting them earlier than other plants that might not handle the cold.

The earliest that you can plant helianthemum in Piedmont 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 fully mature. You can get started a few weeks earlier by starting your helianthemum indoors.

Last Frost Date

On average all chance of frost has passed is on April 15 in Piedmont. In the coldest months of winter you should expect an average low temperature of 5°F.

Since the USDA zone info for Piedmont is just an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Piedmont it frosts late in the year after April 15 be ready to protect your helianthemum in the event of one of those late frosts.

USDA Zone Info for Piedmont

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 Piedmont

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