One of the first steps you take when you are determining your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Huntsville you can estimate when it's a good idea to plant ageratum by using the USDA zone info.

Planting Calendar for Ageratum

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

Since ageratum are not cold tolerant you have to wait until after the last frost has passed before you can plant them.

The earliest that you can plant ageratum in Huntsville 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. Starting your ageratum indoors is a great way to get them started a little bit earlier.

Last Frost Date

In Huntsville the average date of last frost happens on April 15. You can expect an average low temperature of 5°F in the coldest months of winter.

Since the USDA zone info for Huntsville is just an average the actual date of last frost can change quite a bit from year to year. Half of the time in Huntsville you get surprised by a frost after April 15 so just be sure to be ready to cover your ageratum if you have a late frost.

USDA Zone Info for Huntsville

Here is the info for USDA Zone 7b.

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

Plants to Grow in Huntsville

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