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.

In New Haven you can figure out when it's a good idea to plant sweet williams by using the USDA zone info.

Planting Calendar for Sweet Williams

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

Since sweet williams are moderately cold tolerant you can plant them a bit earlier in the year than more sensitive plants.

The earliest that you can plant sweet williams 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 sweet williams and expect a good harvest is probably September. You probably don't want to wait any later than that or else your sweet williams may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your sweet williams indoors.

Last Frost Date

In New Haven the average date of last frost happens on April 15. In the coldest months of winter you can expect an average low temperature of -10°F.

Since the USDA zone info for New Haven may not be accurate from year to year the actual date of last frost will vary from year to year. Since half of the time in New Haven you get surprised by a frost after April 15 be ready to cover your sweet williams if you have a surprise late frost.

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.