The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

One way of determining when it's the best time to plant alternanthera is to consult the USDA zone info for San Marino.

Planting Calendar for Alternanthera

Frost tolerance for alternanthera:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

It's a bad idea to plant alternanthera until after the last frost has passed because they do not do well in cold weather.

The earliest that you can plant alternanthera in San Marino 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 really do well. You can get started a little bit earlier by starting your alternanthera indoors.

Last Frost Date

In San Marino the average date of last frost happens on January 31. You should expect an average low temperature of 30°F in the coldest months of winter.

Just be sure to remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for San Marino and it will vary from year to year. Half of the time in San Marino you get surprised by a frost after January 31 so make sure that you are ready to cover your alternanthera if you have a surprise late frost.

USDA Zone Info for San Marino

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 Marino

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