frostdate name logo in white
frostdate name logo in white

When to Plant Sunflowers in River Grove, IL

Before planting it is a good idea to find your USDA Zone info to figure out your garden 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 River Grove it's possible to figure out when it's a good idea to plant sunflowers.


Planting Calendar for Sunflowers

Frost tolerance for sunflowers: Not tolerant of frost.
When to plant: After the last frost when the weather gets warmer.

Sunflowers are not cold tolerant which means that you have to wait until it warms up after all chance of frost has passed before you can plant them.

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

The earliest that you can plant sunflowers in River Grove 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 sunflowers and expect a good harvest is probably August. Any later than that and your sunflowers may not have a chance to grow to maturity. If you are starting your sunflowers indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

On average the last frost has passed is on April 15 in River Grove. You should expect an average low temperature of -15°F in the coldest months of winter.

Keep in mind that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for River Grove and it changes from year to year. Half of the time in River Grove it frosts late in the year after April 15 so make sure that you are ready to protect your sunflowers in the event of a surprise late frost.

USDA Zone Info for River Grove

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 River Grove

You may be interested in your other planting guides for River Grove.