When can I plant Coreopsis in Zone 3b

The USDA Zone info is a great tool for gardeners to help us figure out our gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for our area.

In Zone 3b you can estimate when it's a good idea to plant coreopsis by looking at the USDA zone info.


Planting Calendar for Coreopsis

Frost tolerance for coreopsis: Tolerant of some frost.
When you should plant them: Up to 5 weeks before last frost.

Coreopsis are one of those plants that can tolerate a little bit of cold weather which means that you can start planting them earlier than plants that are more sensitive to the cold.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant coreopsis
Possibly ok, but a risky time to plant coreopsis
Probably not a good time to plant coreopsis

The earliest that you can plant coreopsis in Zone 3b 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 coreopsis and expect a good harvest is probably August. If you wait any later than that and your coreopsis may not have a chance to fully mature. If you are starting your coreopsis 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 3b. In the coldest months of winter we should expect an average low temperature of -35°F.

It's important to remember that our actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Zone 3b and it can change quite a bit from year to year. Half of the time in Zone 3b it frosts late in the year after May 15 so always be ready to protect your coreopsis in the event of a late frost.

USDA Zone Info for Zone 3b

Here is the info for USDA Zone 3b.

Average Date of Last Frost (spring)May 15
Average Date of First Frost (fall)September 15
Lowest Expected Low-35°F
Highest Expected Low-30°F

This means that on a really cold year, the coldest it will get is -35°F. On most years you should be prepared to experience lows near -30°F.

Plants to Grow in Zone 3b

You may be interested in our other planting guides for Zone 3b.