The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. 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 Zone 4a should be looked at to estimate when you can plant geranium.

Planting Calendar for Geranium

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

Since geranium do not do well in cold weather it is necessary to wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant geranium in Zone 4a 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 geranium and expect a good harvest is probably August. If you wait any later than that and your geranium may not have a chance to grow to maturity. Starting your geranium indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

On average all chance of frost has passed is on May 15 in Zone 4a. It might get as low as -30°F during the coldest months of winter.

Since the USDA zone info for Zone 4a is an average the actual date of last frost is different every year. Since half of the time in Zone 4a last frost occurs after May 15 be ready to cover your geranium in the event of one of those late frosts.

USDA Zone Info for Zone 4a

Here is the info for USDA Zone 4a.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-30°F
Highest Expected Low	-25°F

This means that on a really cold year, the coldest it will get is -30°F. On most years you should be prepared to experience lows near -25°F.

Plants to Grow in Zone 4a

You may be interested in your other planting guides for Zone 4a.