Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The earliest that you can plant lithospermum in Princeton should be estimated by using 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.

You should not plant lithospermum until after the last frost has passed because they do not do well in cold weather.

The earliest that you can plant lithospermum in Princeton 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. Any later than that and your lithospermum may not have a chance to fully mature. You can get started a few weeks earlier by starting your lithospermum indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Princeton. It might get as low as -5°F during the coldest months of winter.

It's important to remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Princeton and it is different every year. Half of the time in Princeton there is a last frost after April 15 so make sure that you are prepared to protect your lithospermum if you have a late frost.

USDA Zone Info for Princeton

Here is the info for USDA Zone 6b.

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

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

Plants to Grow in Princeton

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