The USDA Zone info is a great tool for gardeners to help us figure out your gardening 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 making a decision about when it's possible to plant catharanthus is to examine the USDA zone info for New Haven.

Planting Calendar for Catharanthus

Frost tolerance for catharanthus:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

It's not a good idea to plant catharanthus until after the last frost because they require warm weather.

The earliest that you can plant catharanthus in New Haven is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant catharanthus and expect a good harvest is probably August. Any later than that and your catharanthus may not have a chance to really do well. You can get started a few weeks earlier by starting your catharanthus indoors.

Last Frost Date

On average the last frost is on April 15 in New Haven. You should expect an average low temperature of -10°F in the coldest months of winter.

Always keep in mind that the actual date of last frost is just an average because it is based on the USDA zone info for New Haven and it can change quite a bit from year to year. Half of the time in New Haven last frost occurs after April 15 so be sure to be ready to cover your catharanthus in the event of one of those late frosts.

USDA Zone Info for New Haven

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 New Haven

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