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.

The USDA zone info for Berlin should be reffered to in order to determine when it's a good idea to plant regal geranium.

Planting Calendar for Regal Geranium

Frost tolerance for regal geranium:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

You can plant regal geranium just a tiny bit earlier in the year because they are barely cold tolerant.

The earliest that you can plant regal geranium in Berlin 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 regal geranium and expect a good harvest is probably August. You probably don't want to wait any later than that or else your regal geranium may not have a chance to really do well. You can get started a few weeks earlier by starting your regal geranium indoors.

Last Frost Date

On average the last frost has passed is on May 15 in Berlin. You should expect an average low temperature of -25°F in the coldest months of winter.

Since the USDA zone info for Berlin is an average the actual date of last frost can change quite a bit from year to year. Half of the time in Berlin it frosts late in the year after May 15 so be sure to be ready to protect your regal geranium in the event of one of those late frosts.

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.