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

It's a good idea to figure out when it's a good idea to plant alternanthera by referring to the USDA zone info for Presidio.

Planting Calendar for Alternanthera

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

Since alternanthera do not do well in cold weather it's important to wait until after the last frost before you can plant them.

The earliest that you can plant alternanthera in Presidio 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. Any later than that and your alternanthera may not have a chance to fully mature. You can get started a few weeks earlier by starting your alternanthera indoors.

Last Frost Date

In Presidio the average date of last frost happens on February 15. It might get as low as 20°F during the coldest months of winter.

Just be sure to remember that the actual date of last frost is just an average because it is based on the USDA zone info for Presidio and it will vary from year to year. Half of the time in Presidio it frosts late in the year after February 15 so just be sure to be ready to cover your alternanthera if you have one of those late frosts.

USDA Zone Info for Presidio

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 Presidio

You may be interested in your other planting guides for Presidio.