One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

It's a good idea to figure out when it's possible to plant helianthemum by reviewing the USDA zone info for Hartwell.

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 bit earlier in the year than more sensitive plants.

The earliest that you can plant helianthemum in Hartwell 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. If you wait any later than that and your helianthemum may not have a chance to grow to maturity. If you are starting your helianthemum indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

The average date of last frost is March 15 in Hartwell. In the coldest months of winter you should expect an average low temperature of 10°F.

Keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for Hartwell and it changes from year to year. Half of the time in Hartwell you get surprised by a frost after March 15 so just be sure to be ready to cover your helianthemum in the event of a late frost.

USDA Zone Info for Hartwell

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°F

This means that on a really cold year, the coldest it will get is 10°F. On most years you should be prepared to experience lows near 15°F.

Plants to Grow in Hartwell

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