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 determining when it's possible to plant helianthemum is to use the USDA zone info for Lowell.

Planting Calendar for Helianthemum

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

Helianthemum are moderately cold tolerant which tells us that you can get them planted earlier than plants that are more sensitive to the cold.

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

Last Frost Date

On average all chance of frost has passed is on April 15 in Lowell. You should expect an average low temperature of -10°F in the coldest months of winter.

Always keep in mind that USDA zone info for Lowell may not be accurate from year to year and the actual date of last frost can change quite a bit from year to year. Since half of the time in Lowell you get a frost after April 15 be ready to cover your helianthemum in the event of a late frost.

USDA Zone Info for Lowell

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°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 -5°F.

Plants to Grow in Lowell

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