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When to Plant Flower-of-an-Hour in River Grove, IL

The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The earliest that you can plant flower-of-an-hour in River Grove should be determined by using the USDA zone info.


Planting Calendar for Flower-of-an-Hour

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

Flower-of-an-Hour are one of those plants that can tolerate a tiny bit of cold weather which means that you can start planting them slightly earlier than more sensitive plants.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant flower-of-an-hour
Possibly ok, but a risky time to plant flower-of-an-hour
Probably not a good time to plant flower-of-an-hour

The earliest that you can plant flower-of-an-hour in River Grove 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 flower-of-an-hour and expect a good harvest is probably August. You probably don't want to wait any later than that or else your flower-of-an-hour may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your flower-of-an-hour indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in River Grove. It might get as low as -15°F during the coldest months of winter.

Since the USDA zone info for River Grove may not be accurate from year to year the actual date of last frost changes from year to year. Half of the time in River Grove you get a frost after April 15 so make sure that you are prepared to cover your flower-of-an-hour in the event of a 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.