The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In Arcata you can determine when it's the best time to plant four o' clock by looking at 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.

Four O' Clock require warm weather which tells us that it's necessary to wait until it warms up after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant four o' clock in Arcata 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. You probably don't want to wait any later than that or else your four o' clock may not have a chance to really do well. You can get started a couple of weeks earlier by starting your four o' clock indoors.

Last Frost Date

In Arcata the average date of last frost happens on February 15. You should expect an average low temperature of 25°F in the coldest months of winter.

Since the USDA zone info for Arcata is just an average the actual date of last frost is different every year. Half of the time in Arcata last frost occurs after February 15 so always be ready to protect your four o' clock in the event of one of those late frosts.

USDA Zone Info for Arcata

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 Arcata

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