One of the first steps you take when you are figuring out your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In San Dimas you can estimate 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.

Since four o' clock require warm weather you must wait until after the last frost has passed before you can plant them.

The earliest that you can plant four o' clock in San Dimas is February. However, you really should wait until March 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 San Dimas the average date of last frost happens on January 31. It might get as low as 30°F during the coldest months of winter.

Remember that USDA zone info for San Dimas is not always accurate and the actual date of last frost changes from year to year. Since half of the time in San Dimas you get surprised by a frost after January 31 be ready to cover your four o' clock if you have one of those late frosts.

USDA Zone Info for San Dimas

Here is the info for USDA Zone 10a.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	30°F
Highest Expected Low	35°F

This means that on a really cold year, the coldest it will get is 30°F. On most years you should be prepared to experience lows near 35°F.

Plants to Grow in San Dimas

You may be interested in your other planting guides for San Dimas.