The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In Johnston you can determine when to plant geranium by reviewing the USDA zone info.

Planting Calendar for Geranium

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

Geranium do not do well in cold weather which tells us that it is important to wait until it warms up after the last frost before you can plant them.

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

Last Frost Date

In Johnston the average date of last frost happens on April 15. In the coldest months of winter you should expect an average low temperature of -20°F.

Remember that the actual date of last frost is just an average because it is based on the USDA zone info for Johnston and it can change quite a bit from year to year. Since half of the time in Johnston you get a frost after April 15 be ready to protect your geranium if you have one of those late frosts.

USDA Zone Info for Johnston

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 Johnston

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