One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. 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 Campbell should be determined 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 when the weather gets warmer.

Four O' Clock require warm weather which means that it is important 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 Campbell 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. You can get started a little bit earlier by starting your four o' clock indoors.

Last Frost Date

The average date of last frost is April 15 in Campbell. In the coldest months of winter you can expect an average low temperature of -10°F.

Since the USDA zone info for Campbell may not be accurate from year to year the actual date of last frost can change quite a bit from year to year. Since half of the time in Campbell it frosts late in the year after April 15 be ready to protect your four o' clock if you have a surprise late frost.

USDA Zone Info for Campbell

Here is the info for USDA Zone 6a.

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

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

Plants to Grow in Campbell

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