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.

The USDA zone info for Zone 4b should be used to estimate when it's the best time to plant chrysanthemums.

Planting Calendar for Chrysanthemums

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

Chrysanthemums do ok in mild cold which tells us that you can plant them a bit earlier in the year than other plants that might not handle the cold.

The earliest that you can plant chrysanthemums 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 chrysanthemums and expect a good harvest is probably August. If you wait any later than that and your chrysanthemums may not have a chance to fully mature. If you are starting your chrysanthemums indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

The average date of last frost is May 15 in Zone 4b. It might get as low as -25°F during the coldest months of winter.

It's important to remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Zone 4b and it can change quite a bit from year to year. Since half of the time in Zone 4b last frost occurs after May 15 be ready to protect your chrysanthemums in the event of one of those late frosts.

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.