When to Plant Four-o-clock flower in Harvey, IL

One of the first steps you take when you are getting a good idea your gardening schedule is find your 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 reviewing the USDA zone info for Harvey you will be able to estimate when it's a good idea to plant four-o-clock flower.


Planting Calendar for Four-o-clock flower

Frost tolerance for four-o-clock flower: Not tolerant of frost.
When to plant: After all chance of frost has passed.

Four-o-clock flower are not cold tolerant which tells us that you must wait until it warms up after the last frost when the weather gets warmer before you can plant them.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant four-o-clock flower
Possibly ok, but a risky time to plant four-o-clock flower
Probably not a good time to plant four-o-clock flower

The earliest that you can plant four-o-clock flower in Harvey 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 four-o-clock flower and expect a good harvest is probably August. If you wait any later than that and your four-o-clock flower may not have a chance to really do well. You can get started a couple of weeks earlier by starting your four-o-clock flower indoors.

Last Frost Date

On average the last frost has passed is on April 15 in Harvey. It might get as low as -15°F during the coldest months of winter.

Always keep in mind that USDA zone info for Harvey is just an average and the actual date of last frost is different every year. Since half of the time in Harvey there is a last frost after April 15 be ready to cover your four-o-clock flower in the event of a late frost.

USDA Zone Info for Harvey

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 Harvey

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