The USDA Zone info is a great tool for gardeners to help us figure out 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.

You should be able to estimate when it's a good idea to plant lupine by checking out the USDA zone info for Princeton.

Planting Calendar for Lupine

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

You can plant lupine just a bit earlier in the year because they are moderately cold tolerant.

The earliest that you can plant lupine in Princeton is March. However, you really should wait until April if you don't want to take any chances.

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

Last Frost Date

In Princeton the average date of last frost happens on May 15. It might get as low as -30°F during the coldest months of winter.

Remember that the actual date of last frost is just an average because it is based on the USDA zone info for Princeton and it is different every year. Half of the time in Princeton last frost occurs after May 15 so always be ready to cover your lupine if you have a late frost.

USDA Zone Info for Princeton

Here is the info for USDA Zone 4a.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-30°F
Highest Expected Low	-25°F

This means that on a really cold year, the coldest it will get is -30°F. On most years you should be prepared to experience lows near -25°F.

Plants to Grow in Princeton

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