The USDA Zone info is a great tool for gardeners to help us estimate 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 it's the best time to plant hosta in Zone 4b by checking out the USDA zone info.

Planting Calendar for Hosta

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

Hosta do ok in mild cold which tells us that you can plant them a little bit earlier in the year than more sensitive plants.

The earliest that you can plant hosta 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 hosta and expect a good harvest is probably August. You probably don't want to wait any later than that or else your hosta may not have a chance to really do well. If you are starting your hosta indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

In Zone 4b the average date of last frost happens on May 15. In the coldest months of winter you should expect an average low temperature of -25°F.

Since the USDA zone info for Zone 4b is just an average the actual date of last frost is different every year. Half of the time in Zone 4b there is a last frost after May 15 so just be sure to be ready to protect your hosta if you have a surprise 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.