One of the best tools that you have as gardeners to help us determine 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.

A common way of making a decision about when it's a good idea to plant alternanthera is to use the USDA zone info for Columbia.

Planting Calendar for Alternanthera

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

Alternanthera do not do well in cold weather which tells us that it is necessary to wait until it warms up after all chance of frost has passed before you can plant them.

The earliest that you can plant alternanthera in Columbia 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. You probably don't want to wait any later than that or else your alternanthera may not have a chance to really do well. 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

The average date of last frost is March 15 in Columbia. It might get as low as 15°F during the coldest months of winter.

Keep in mind that the actual date of last frost is just an average because it is based on the USDA zone info for Columbia and it is different every year. Half of the time in Columbia there is a last frost after March 15 so just be sure to be ready to cover your alternanthera in the event of one of those late frosts.

USDA Zone Info for Columbia

Here is the info for USDA Zone 8b.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	15°F
Highest Expected Low	20°F

This means that on a really cold year, the coldest it will get is 15°F. On most years you should be prepared to experience lows near 20°F.

Plants to Grow in Columbia

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