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.

In Warrenton you can figure out when it's possible to plant ageratum by reviewing 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.

You really shouldn't plant ageratum until after the last frost when the weather gets warmer because they are not cold tolerant.

The earliest that you can plant ageratum in Warrenton is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant ageratum and expect a good harvest is probably September. If you wait any later than that and your ageratum may not have a chance to really do well. Starting your ageratum indoors is a great way to get them started a little bit earlier.

Last Frost Date

In Warrenton the average date of last frost happens on February 15. It might get as low as 20°F during the coldest months of winter.

Just be sure to remember that the actual date of last frost is just an average because it is based on the USDA zone info for Warrenton and it changes from year to year. Since half of the time in Warrenton you get a frost after February 15 be ready to cover your ageratum in the event of one of those late frosts.

USDA Zone Info for Warrenton

Here is the info for USDA Zone 9a.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	20°F
Highest Expected Low	25°F

This means that on a really cold year, the coldest it will get is 20°F. On most years you should be prepared to experience lows near 25°F.

Plants to Grow in Warrenton

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