Before planting it is a good idea to find your USDA Zone info to determine 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 using the USDA zone info for Piedmont you will be able to figure out when it's a good idea 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 tend to make it in moderate cold which tells us that you can plant them a little earlier in the year than other plants that might not handle the cold.

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

The last month that you can plant helianthemum and expect a good harvest is probably October. Any later than that and your helianthemum may not have a chance to really do well. You can get started a couple of weeks earlier by starting your helianthemum indoors.

Last Frost Date

In Piedmont the average date of last frost happens on January 31. You can expect an average low temperature of 30°F in the coldest months of winter.

Always keep in mind that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Piedmont and it will vary from year to year. Half of the time in Piedmont you get a frost after January 31 so just be sure to be ready to cover your helianthemum if you have a surprise late frost.

USDA Zone Info for Piedmont

Here is the info for USDA Zone 10a.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	30°F
Highest Expected Low	35°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 35°F.

Plants to Grow in Piedmont

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