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.

One way of estimating when to plant alternaria is to examine the USDA zone info for Columbia.

Planting Calendar for Alternaria

Frost tolerance for alternaria:	Not tolerant of frost.
When to plant:	After the last frost.

You should not plant alternaria until after all chance of frost has passed because they do not do well in cold weather.

The earliest that you can plant alternaria 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 alternaria and expect a good harvest is probably August. If you wait any later than that and your alternaria may not have a chance to fully mature. You can get started a little bit earlier by starting your alternaria indoors.

Last Frost Date

On average all chance of frost has passed is on March 15 in Columbia. In the coldest months of winter you can expect an average low temperature of 10°F.

It's important to remember that the actual date of last frost is an average because it is based on the USDA zone info for Columbia and it will vary from year to year. Since half of the time in Columbia there is a last frost after March 15 be ready to cover your alternaria in the event of a surprise late frost.

USDA Zone Info for Columbia

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°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 15°F.

Plants to Grow in Columbia

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