Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Zone 9a should be looked at to determine when to plant alternanthera.

Planting Calendar for Alternanthera

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

Since alternanthera are not cold tolerant you need to wait until after the last frost before you can plant them.

The earliest that you can plant alternanthera in Zone 9a is March. However, you really should wait until April 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. You probably don't want to wait any later than that or else your alternanthera may not have a chance to fully mature. Starting your alternanthera indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average the last frost has passed is on February 15 in Zone 9a. You can expect an average low temperature of 20°F in the coldest months of winter.

Always keep in mind that USDA zone info for Zone 9a is just an average and the actual date of last frost can change quite a bit from year to year. Half of the time in Zone 9a there is a last frost after February 15 so be sure to be ready to cover your alternanthera if you have a late frost.

USDA Zone Info for Zone 9a

Here is the info for USDA Zone 9a.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	20°F
Highest Expected Low	25°F

This means that on a really cold year, the coldest it will get is 20°F. On most years you should be prepared to experience lows near 25°F.

Plants to Grow in Zone 9a

You may be interested in your other planting guides for Zone 9a.