Before planting it is a good idea to find your USDA Zone info to estimate 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 getting a good idea when you can plant helianthemum is to use the USDA zone info for Sandwich.

Planting Calendar for Helianthemum

Frost tolerance for helianthemum:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

You can plant helianthemum a little bit earlier in the year because they are moderately cold tolerant.

The earliest that you can plant helianthemum in Sandwich 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. Starting your helianthemum indoors is a great way to get them started a few weeks earlier.

Last Frost Date

In Sandwich the average date of last frost happens on April 15. In the coldest months of winter you can expect an average low temperature of -15°F.

Keep in mind that USDA zone info for Sandwich is just an average and the actual date of last frost is different every year. Since half of the time in Sandwich last frost occurs after April 15 be ready to cover your helianthemum in the event of one of those late frosts.

USDA Zone Info for Sandwich

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 Sandwich

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