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.

You can figure out when it's possible to plant helianthemum in New Haven by referring to 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 do ok in moderate cold which means that you can plant them a bit earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant helianthemum in New Haven 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 couple of weeks earlier by starting your helianthemum indoors.

Last Frost Date

The average date of last frost is April 15 in New Haven. You can expect an average low temperature of 0°F in the coldest months of winter.

Just be sure to remember that USDA zone info for New Haven may not be accurate from year to year and the actual date of last frost changes from year to year. Since half of the time in New Haven you get surprised by a frost after April 15 be ready to protect your helianthemum if you have a surprise late frost.

USDA Zone Info for New Haven

Here is the info for USDA Zone 7a.

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

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

Plants to Grow in New Haven

You may be interested in your other planting guides for New Haven.