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 possible to estimate when it's a good idea to plant alternanthera by looking at the USDA zone info for Kenai.

Planting Calendar for Alternanthera

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

Alternanthera require warm weather which means that you really should wait until it warms up after the last frost before you can plant them.

The earliest that you can plant alternanthera in Kenai is May. However, you really should wait until June 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. Any later than that and your alternanthera may not have a chance to fully mature. Starting your alternanthera indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

The average date of last frost is May 15 in Kenai. It might get as low as -25°F during the coldest months of winter.

Keep in mind that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Kenai and it is different every year. Half of the time in Kenai it frosts late in the year after May 15 so make sure that you are prepared to protect your alternanthera in the event of one of those late frosts.

USDA Zone Info for Kenai

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°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 -20°F.

Plants to Grow in Kenai

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