Before planting it is a good idea to find your USDA Zone info to estimate 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 estimate when it's possible to plant coreopsis by using the USDA zone info for Windsor.

Planting Calendar for Coreopsis

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

Coreopsis do ok in moderate cold which tells us that you can plant them a little bit earlier in the year than other frost tender plants.

The earliest that you can plant coreopsis in Windsor is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant coreopsis and expect a good harvest is probably September. If you wait any later than that and your coreopsis may not have a chance to really do well. 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

On average the last frost is on April 15 in Windsor. In the coldest months of winter you can expect an average low temperature of -15°F.

It's important to remember that USDA zone info for Windsor is an average and the actual date of last frost can change quite a bit from year to year. Half of the time in Windsor you get surprised by a frost after April 15 so be sure to be ready to protect your coreopsis if you have one of those late frosts.

USDA Zone Info for Windsor

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-15°F
Highest Expected Low	-10°F

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Windsor

You may be interested in your other planting guides for Windsor.