One of the first steps you take when you are determining your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By looking at the USDA zone info for Mason City you will be able to figure out when it's a good idea to plant ageratum.

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 it's important to wait until after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant ageratum in Mason City 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. Any later than that and your ageratum may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your ageratum indoors.

Last Frost Date

On average the last frost is on April 15 in Mason City. You can expect an average low temperature of -20°F in the coldest months of winter.

It's important to remember that USDA zone info for Mason City is an average and the actual date of last frost will vary from year to year. Half of the time in Mason City it frosts late in the year after April 15 so always be ready to protect your ageratum in the event of one of those late frosts.

USDA Zone Info for Mason City

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°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 -15°F.

Plants to Grow in Mason City

You may be interested in your other planting guides for Mason City.