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

The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By looking at the USDA zone info for Washington you should be able to figure out 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 do not do well in cold weather which tells us that it is important to wait until it warms up after the last frost has passed 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 Washington 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. You probably don't want to wait any later than that or else your four-o-clock flower may not have a chance to fully mature. You can get started a little bit earlier by starting your four-o-clock flower indoors.

Last Frost Date

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

Since the USDA zone info for Washington is an average the actual date of last frost is different every year. Since half of the time in Washington you get a frost after April 15 be ready to protect your four-o-clock flower if you have one of those late frosts.

USDA Zone Info for Washington

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 Washington

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