The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The earliest that you can plant lithospermum in New Haven should be figured out by reviewing the USDA zone info.

Planting Calendar for Lithospermum

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

Lithospermum do not do well in cold weather which tells us that it is important to wait until it warms up after the last frost when the weather gets warmer before you can plant them.

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

Last Frost Date

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

It's important to remember that USDA zone info for New Haven is just an average and the actual date of last frost is different every year. Half of the time in New Haven you get surprised by a frost after April 15 so be sure to be ready to cover your lithospermum in the event of 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.