When to Plant Peonies in Oswego, IL

The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By reviewing the USDA zone info for Oswego you should be able to determine when it's the best time to plant peonies.


Planting Calendar for Peonies

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

You can plant peonies a bit earlier in the year because they are one of those plants that can tolerate a tiny bit of cold weather.

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

The earliest that you can plant peonies in Oswego 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 peonies and expect a good harvest is probably August. You probably don't want to wait any later than that or else your peonies may not have a chance to grow to maturity. If you are starting your peonies indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Oswego. You should expect an average low temperature of -15°F in the coldest months of winter.

It's important to remember that USDA zone info for Oswego may not be accurate from year to year and the actual date of last frost can change quite a bit from year to year. Half of the time in Oswego last frost occurs after April 15 so always be ready to cover your peonies in the event of a surprise late frost.

USDA Zone Info for Oswego

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 Oswego

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