The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

A common way of figuring out when to plant alternanthera is to use the USDA zone info for Manhattan.

Planting Calendar for Alternanthera

Frost tolerance for alternanthera:	Not tolerant of frost.
When to plant:	After the last 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 Manhattan is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant alternanthera and expect a good harvest is probably August. If you wait any later than that and your alternanthera may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your alternanthera indoors.

Last Frost Date

The average date of last frost is April 15 in Manhattan. In the coldest months of winter you can expect an average low temperature of -10°F.

Just be sure to remember that USDA zone info for Manhattan is just an average and the actual date of last frost will vary from year to year. Since half of the time in Manhattan it frosts late in the year after April 15 be ready to cover your alternanthera in the event of a late frost.

USDA Zone Info for Manhattan

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Manhattan

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