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 Oskaloosa you can figure out when to plant ageratum by looking at the USDA zone info.

Planting Calendar for Ageratum

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

Since ageratum require warm weather you need to wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant ageratum in Oskaloosa 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. You probably don't want to wait any later than that or else your ageratum may not have a chance to grow to maturity. Starting your ageratum indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average all chance of frost has passed is on April 15 in Oskaloosa. In the coldest months of winter you can expect an average low temperature of -15°F.

Since the USDA zone info for Oskaloosa is not always accurate the actual date of last frost changes from year to year. Since half of the time in Oskaloosa you get surprised by a frost after April 15 be ready to cover your ageratum in the event of one of those late frosts.

USDA Zone Info for Oskaloosa

Here is the info for USDA Zone 5b.

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

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Oskaloosa

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