Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By referring to the USDA zone info for La Mesa you should be able to estimate when it's a good idea to plant alternanthera.

Planting Calendar for Alternanthera

Frost tolerance for alternanthera:	Not tolerant of frost.
When to plant:	After the last frost.

It's probably a bad idea to plant alternanthera until after the last frost has passed because they are not cold tolerant.

The earliest that you can plant alternanthera 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 alternanthera and expect a good harvest is probably September. Any later than that and your alternanthera may not have a chance to grow to maturity. If you are starting your alternanthera indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

In La Mesa 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 the actual date of last frost may not be accurate from year to year 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 it frosts late in the year after January 31 so make sure that you are prepared to cover your alternanthera if you have a late frost.

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.