Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

You should be able to figure out when to plant chrysanthemum by referring to the USDA zone info for Zone 4b.

Planting Calendar for Chrysanthemum

Frost tolerance for chrysanthemum:	Not tolerant of frost.
When to plant:	After the last frost has passed.

Since chrysanthemum require warm weather you really should wait until after all chance of frost has passed before you can plant them.

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

The last month that you can plant chrysanthemum and expect a good harvest is probably August. Any later than that and your chrysanthemum may not have a chance to grow to maturity. Starting your chrysanthemum indoors is a great way to get them started a little bit 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.

It's important to remember that USDA zone info for Zone 4b may not be accurate from year to year and 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 chrysanthemum 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.