Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In Monticello you can determine when 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.

Since ageratum require warm weather it's necessary to wait until after the last frost has passed before you can plant them.

The earliest that you can plant ageratum in Monticello is May. However, you really should wait until June 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. You probably don't want to wait any later than that or else 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 Monticello the average date of last frost happens on May 15. It might get as low as -25°F during the coldest months of winter.

Since the USDA zone info for Monticello is not always accurate the actual date of last frost is different every year. Half of the time in Monticello it frosts late in the year after May 15 so be sure to be ready to protect your ageratum if you have one of those late frosts.

USDA Zone Info for Monticello

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

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

Plants to Grow in Monticello

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