Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The first chance to plant four o' clock in Oskaloosa should be figured out by checking out 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.

It's probably a bad idea to plant four o' clock until after the last frost because they require warm weather.

The earliest that you can plant four o' clock in Oskaloosa 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 grow to maturity. 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

In Oskaloosa 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.

Keep in mind that USDA zone info for Oskaloosa may not be accurate from year to year and the actual date of last frost can change quite a bit from year to year. Half of the time in Oskaloosa you get surprised by a frost after April 15 so be sure to be ready to protect your four o' clock if you have a late frost.

USDA Zone Info for Oskaloosa

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 Oskaloosa

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