When to Plant Four O' Clock in Washington, IL

Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The best time to plant four o' clock in Washington should be determined by referring to the USDA zone info.


Planting Calendar for Four O' Clock

Frost tolerance for four o' clock: Not tolerant of frost.
When to plant: After the last frost when the weather gets warmer.

It's probably a bad idea to plant four o' clock until after the last frost has passed because they are not cold tolerant.

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

The earliest that you can plant four o' clock 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 and expect a good harvest is probably August. If you wait any later than that and your four o' clock may not have a chance to really do well. If you are starting your four o' clock 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 when the weather gets warmer is on April 15 in Washington. You can expect an average low temperature of -15°F in the coldest months of winter.

Since the USDA zone info for Washington is not always accurate the actual date of last frost changes from year to year. Half of the time in Washington you get surprised by a frost after April 15 so be sure to be ready to cover your four o' clock if you have a late frost.

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.