The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The first chance to plant helianthemum in Richmond Hill should be determined by using the USDA zone info.

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 get them planted earlier than more sensitive plants.

The earliest that you can plant helianthemum in Richmond Hill 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 grow to maturity. You can get started a couple of weeks earlier by starting your helianthemum indoors.

Last Frost Date

On average the last frost has passed is on March 15 in Richmond Hill. You should expect an average low temperature of 15°F in the coldest months of winter.

Keep in mind that USDA zone info for Richmond Hill is just an average and the actual date of last frost will vary from year to year. Since half of the time in Richmond Hill you get a frost after March 15 be ready to protect your helianthemum in the event of a surprise late frost.

USDA Zone Info for Richmond Hill

Here is the info for USDA Zone 8b.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	15°F
Highest Expected Low	20°F

This means that on a really cold year, the coldest it will get is 15°F. On most years you should be prepared to experience lows near 20°F.

Plants to Grow in Richmond Hill

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