One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By referring to the USDA zone info for Whittier you should be able 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 when the weather gets warmer.

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

The earliest that you can plant alternanthera in Whittier 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. If you wait 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

On average all chance of frost has passed is on January 31 in Whittier. It might get as low as 30°F during the coldest months of winter.

Remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Whittier and it will vary from year to year. Since half of the time in Whittier you get a frost after January 31 be ready to cover your alternanthera in the event of one of those late frosts.

USDA Zone Info for Whittier

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 Whittier

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