One of the best tools that you have as gardeners to help us estimate 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.

The USDA zone info for Richmond should be used to figure out when it's possible 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 do well in moderate cold which means that you can get them planted earlier than other frost tender plants.

The earliest that you can plant helianthemum in Richmond 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. You probably don't want to wait any later than that or else your helianthemum may not have a chance to fully mature. 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

The average date of last frost is April 15 in Richmond. You can expect an average low temperature of -10°F in the coldest months of winter.

Since the USDA zone info for Richmond is just an average the actual date of last frost can change quite a bit from year to year. Half of the time in Richmond there is a last frost after April 15 so make sure that you are prepared to cover your helianthemum if you have a surprise late frost.

USDA Zone Info for Richmond

Here is the info for USDA Zone 6a.

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

Plants to Grow in Richmond

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