The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

A common way of making a decision about when it's a good idea to plant ageratum is to consult the USDA zone info for Marshall.

Planting Calendar for Ageratum

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

Ageratum are not cold tolerant which means that you must wait until it warms up after the last frost has passed before you can plant them.

The earliest that you can plant ageratum in Marshall 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. You can get started a couple of weeks earlier by starting your ageratum indoors.

Last Frost Date

On average all chance of frost has passed is on May 15 in Marshall. You can expect an average low temperature of -25°F in the coldest months of winter.

Always keep in mind that USDA zone info for Marshall is not always accurate and the actual date of last frost changes from year to year. Half of the time in Marshall it frosts late in the year after May 15 so be sure to be ready to cover your ageratum if you have one of those late frosts.

USDA Zone Info for Marshall

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 Marshall

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