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

One way of making a decision about when you can plant helianthemum is to refer to the USDA zone info for Chelsea.

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 plant them a little bit earlier than other frost tender plants.

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

Last Frost Date

On average the last frost is on March 15 in Chelsea. You should expect an average low temperature of 10°F in the coldest months of winter.

It's important to remember that USDA zone info for Chelsea may not be accurate from year to year and the actual date of last frost will vary from year to year. Half of the time in Chelsea it frosts late in the year after March 15 so be sure to be ready to cover your helianthemum if you have one of those late frosts.

USDA Zone Info for Chelsea

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 Chelsea

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