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 Berlin you can estimate when it's the best time 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 the last frost has passed.

Since ageratum are not cold tolerant you really should wait until after the last frost has passed before you can plant them.

The earliest that you can plant ageratum in Berlin 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 few weeks earlier.

Last Frost Date

In Berlin the average date of last frost happens on May 15. In the coldest months of winter you can expect an average low temperature of -25°F.

Since the USDA zone info for Berlin is just an average the actual date of last frost will vary from year to year. Since half of the time in Berlin you get a frost after May 15 be ready to protect your ageratum in the event of a surprise late frost.

USDA Zone Info for Berlin

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 Berlin

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