One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The USDA zone info for Windsor should be used to figure out when it's the best time 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 are not cold tolerant it is important to wait until after the last frost before you can plant them.

The earliest that you can plant alternanthera in Windsor 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 really do well. Starting your alternanthera indoors is a great way to get them started a few weeks earlier.

Last Frost Date

In Windsor the average date of last frost happens on February 15. It might get as low as 25°F during the coldest months of winter.

Always keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for Windsor and it changes from year to year. Half of the time in Windsor you get a frost after February 15 so make sure that you are prepared to protect your alternanthera if you have a late frost.

USDA Zone Info for Windsor

Here is the info for USDA Zone 9b.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	25°F
Highest Expected Low	30°F

This means that on a really cold year, the coldest it will get is 25°F. On most years you should be prepared to experience lows near 30°F.

Plants to Grow in Windsor

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