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 best time to plant helianthemum in Worcester can be determined by checking out 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 tend to make it in mild cold which tells us that you can plant them a little bit earlier in the year than other frost tender plants.

The earliest that you can plant helianthemum in Worcester 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 fully mature. If you are starting your helianthemum indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

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

Just be sure to remember that USDA zone info for Worcester is an average and the actual date of last frost will vary from year to year. Since half of the time in Worcester there is a last frost after April 15 be ready to cover your helianthemum in the event of a late frost.

USDA Zone Info for Worcester

Here is the info for USDA Zone 5b.

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

Plants to Grow in Worcester

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