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.

In Zone 4a you can estimate when you can plant lupine by reviewing 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.

Lupine tend to make it in moderate cold which tells us that you can plant them a little earlier in the year than other frost tender plants.

The earliest that you can plant lupine in Zone 4a 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. If you wait any later than that and your lupine may not have a chance to fully mature. Starting your lupine indoors is a great way to get them started a few weeks earlier.

Last Frost Date

In Zone 4a the average date of last frost happens on May 15. You should expect an average low temperature of -30°F in the coldest months of winter.

Since the USDA zone info for Zone 4a is an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Zone 4a there is a last frost after May 15 be ready to cover your lupine if you have one of those late frosts.

USDA Zone Info for Zone 4a

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 Zone 4a

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