One of the first steps you take when you are getting a good idea your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In Oswego you can figure out when it's possible to plant coreopsis by looking at the USDA zone info.

Planting Calendar for Coreopsis

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

Since coreopsis are one of those plants that can tolerate a little bit of cold weather you can plant them a little earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant coreopsis in Oswego 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. Any later than that and your coreopsis may not have a chance to grow to maturity. If you are starting your coreopsis indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

In Oswego the average date of last frost happens on April 15. You can expect an average low temperature of -10°F in the coldest months of winter.

Just be sure to remember that USDA zone info for Oswego is an average and the actual date of last frost changes from year to year. Half of the time in Oswego there is a last frost after April 15 so make sure that you are prepared to protect your coreopsis in the event of a surprise late frost.

USDA Zone Info for Oswego

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Oswego

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