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 can figure out when you can plant lupine in Zone 4b by looking at the USDA zone info.

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 a little earlier in the year because they do well in moderate cold.

The earliest that you can plant lupine in Zone 4b 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 few weeks earlier by starting your lupine indoors.

Last Frost Date

The average date of last frost is May 15 in Zone 4b. You can expect an average low temperature of -25°F in the coldest months of winter.

It's important to remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Zone 4b and it can change quite a bit from year to year. Half of the time in Zone 4b last frost occurs after May 15 so be sure to be ready to cover your lupine if you have a late frost.

USDA Zone Info for Zone 4b

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Zone 4b

You may be interested in your other planting guides for Zone 4b.