When to Plant Geranium in Oswego, IL

One of the best tools that you have as gardeners to help us determine your gardening schedule is the 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.

By referring to the USDA zone info for Oswego you will be able to figure out when it's a good idea to plant geranium.


Planting Calendar for Geranium

Frost tolerance for geranium: Not tolerant of frost.
When to plant: After the last frost has passed.

Since geranium do not do well in cold weather you have to wait until after all chance of frost has passed before you can plant them.

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

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

Last Frost Date

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

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 Oswego and it changes from year to year. Half of the time in Oswego you get a frost after April 15 so just be sure to be ready to cover your geranium if you have one of those late frosts.

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.