The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The first opportunity to plant helianthemum in Manhattan can be figured out by looking at 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 a little bit of cold which means that you can plant them just a bit earlier in the year than other frost tender plants.

The earliest that you can plant helianthemum in Manhattan 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 really do well. You can get started a little bit earlier by starting your helianthemum indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Manhattan. In the coldest months of winter you can expect an average low temperature of -10°F.

Remember that the actual date of last frost is an average because it is based on the USDA zone info for Manhattan and it is different every year. Since half of the time in Manhattan 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 Manhattan

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 Manhattan

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