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

A common way of estimating when it's the best time to plant four-o-clock flower is to refer to the USDA zone info for Salem.

Planting Calendar for Four-o-clock flower

Frost tolerance for four-o-clock flower:	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 flower until after the last frost has passed because they do not do well in cold weather.

The earliest that you can plant four-o-clock flower in Salem 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 really do well. You can get started a few weeks earlier by starting your four-o-clock flower indoors.

Last Frost Date

In Salem the average date of last frost happens on April 15. You should expect an average low temperature of 5°F in the coldest months of winter.

Keep in mind 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 Salem and it will vary from year to year. Half of the time in Salem it frosts late in the year after April 15 so just be sure to be ready to cover your four-o-clock flower in the event of a surprise late frost.

USDA Zone Info for Salem

Here is the info for USDA Zone 7b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	5°F
Highest Expected Low	10°F

This means that on a really cold year, the coldest it will get is 5°F. On most years you should be prepared to experience lows near 10°F.

Plants to Grow in Salem

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