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

You can estimate when it's possible to plant xerianthemum in Zone 4b by looking at the USDA zone info.

Planting Calendar for Xerianthemum

Frost tolerance for xerianthemum:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

You can plant xerianthemum just a tiny bit earlier in the year because they do ok in moderate cold.

The earliest that you can plant xerianthemum in Zone 4b is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant xerianthemum and expect a good harvest is probably August. Any later than that and your xerianthemum may not have a chance to grow to maturity. If you are starting your xerianthemum indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

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

Just be sure to remember that the actual date of last frost is an average because it is based on the USDA zone info for Zone 4b and it will vary from year to year. Half of the time in Zone 4b you get a frost after May 15 so always be ready to protect your xerianthemum in the event of 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.