When to Plant Petunias in Harwood Heights, 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.

It's possible to estimate when it's a good idea to plant petunias by checking out the USDA zone info for Harwood Heights.


Planting Calendar for Petunias

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

Since petunias do ok in moderate cold you can plant them just a tiny bit earlier in the year than other plants that might not handle the cold.

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

The earliest that you can plant petunias in Harwood Heights 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 petunias and expect a good harvest is probably August. Any later than that and your petunias may not have a chance to grow to maturity. Starting your petunias indoors is a great way to get them started a little bit earlier.

Last Frost Date

In Harwood Heights 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.

Just be sure to remember 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 Harwood Heights and it will vary from year to year. Since half of the time in Harwood Heights it frosts late in the year after April 15 be ready to protect your petunias if you have a surprise late frost.

USDA Zone Info for Harwood Heights

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 Harwood Heights

You may be interested in your other planting guides for Harwood Heights.