Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Zone 4b should be used to determine when it's possible to plant digitalis.

Planting Calendar for Digitalis

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

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

The earliest that you can plant digitalis 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 digitalis and expect a good harvest is probably August. Any later than that and your digitalis may not have a chance to grow to maturity. Starting your digitalis indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average the last frost is on May 15 in Zone 4b. 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. Since half of the time in Zone 4b you get a frost after May 15 be ready to protect your digitalis 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.