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When to Plant Four-o-clock flower in San Francisco, CA

One of the first steps you take when you are determining your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In San Francisco you can estimate when to plant four-o-clock flower by using the USDA zone info.


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.

Four-o-clock flower do not do well in cold weather which tells us that it's important to wait until it warms up after the last frost has passed before you can plant them.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant four-o-clock flower
Possibly ok, but a risky time to plant four-o-clock flower
Probably not a good time to plant four-o-clock flower

The earliest that you can plant four-o-clock flower in San Francisco 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 flower and expect a good harvest is probably September. Any later than that and your four-o-clock flower may not have a chance to fully mature. Starting your four-o-clock flower indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

In San Francisco the average date of last frost happens on January 31. In the coldest months of winter you should expect an average low temperature of 35°F.

It's important to remember that USDA zone info for San Francisco is not always accurate and the actual date of last frost will vary from year to year. Half of the time in San Francisco you get a frost after January 31 so make sure that you are prepared to cover your four-o-clock flower if you have a surprise late frost.

USDA Zone Info for San Francisco

Here is the info for USDA Zone 10b.

Average Date of Last Frost (spring)January 31
Average Date of First Frost (fall)December 15
Lowest Expected Low35°F
Highest Expected Low40°F

This means that on a really cold year, the coldest it will get is 35°F. On most years you should be prepared to experience lows near 40°F.

Plants to Grow in San Francisco

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