Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A common way of estimating when to plant helianthemum is to use the USDA zone info for Bristol.

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 a little bit of cold which means that you can plant them a little earlier in the year than more sensitive plants.

The earliest that you can plant helianthemum in Bristol 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

The average date of last frost is April 15 in Bristol. You can expect an average low temperature of -5°F in the coldest months of winter.

Just be sure to remember that USDA zone info for Bristol is an average and the actual date of last frost changes from year to year. Half of the time in Bristol it frosts late in the year after April 15 so always be ready to protect your helianthemum in the event of a surprise late frost.

USDA Zone Info for Bristol

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in Bristol

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