The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You can estimate when it's the best time to plant ageratum in Columbia by reviewing the USDA zone info.

Planting Calendar for Ageratum

Frost tolerance for ageratum:	Not tolerant of frost.
When to plant:	After the last frost has passed.

It's not a good idea to plant ageratum until after all chance of frost has passed because they do not do well in cold weather.

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

Last Frost Date

The average date of last frost is April 15 in Columbia. You should expect an average low temperature of -5°F in the coldest months of winter.

Just be sure to remember that USDA zone info for Columbia is not always accurate and the actual date of last frost can change quite a bit from year to year. Half of the time in Columbia there is a last frost after April 15 so make sure that you are ready to protect your ageratum in the event of a late frost.

USDA Zone Info for Columbia

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in Columbia

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