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.

You will be able to determine when it's a good idea to plant four o' clock by referring to the USDA zone info for Williams.

Planting Calendar for Four O' Clock

Frost tolerance for four o' clock:	Not tolerant of frost.
When to plant:	After the last frost has passed.

Four O' Clock require warm weather which means that you need to wait until it warms up after all chance of frost has passed before you can plant them.

The earliest that you can plant four o' clock in Williams is March. However, you really should wait until April 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 September. Any later than that and your four o' clock may not have a chance to fully mature. 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 Williams the average date of last frost happens on February 15. It might get as low as 25°F during the coldest months of winter.

Since the USDA zone info for Williams is not always accurate the actual date of last frost is different every year. Since half of the time in Williams you get a frost after February 15 be ready to protect your four o' clock if you have one of those late frosts.

USDA Zone Info for Williams

Here is the info for USDA Zone 9b.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	25°F
Highest Expected Low	30°F

This means that on a really cold year, the coldest it will get is 25°F. On most years you should be prepared to experience lows near 30°F.

Plants to Grow in Williams

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