One of the first steps you take when you are making a decision about 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.

One way of figuring out when it's the best time to plant four-o-clock flower is to look at the USDA zone info for La Mesa.

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 when the weather gets warmer.

You should not plant four-o-clock flower until after the last frost when the weather gets warmer because they are not cold tolerant.

The earliest that you can plant four-o-clock flower in La Mesa 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. If you wait any later than that and your four-o-clock flower may not have a chance to fully mature. If you are starting your four-o-clock flower indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on January 31 in La Mesa. In the coldest months of winter you should expect an average low temperature of 30°F.

Remember that the actual date of last frost is just an average because it is based on the USDA zone info for La Mesa and it will vary from year to year. Half of the time in La Mesa there is a last frost after January 31 so make sure that you are prepared to cover your four-o-clock flower in the event of one of those late frosts.

USDA Zone Info for La Mesa

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 La Mesa

You may be interested in your other planting guides for La Mesa.