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.

By referring to the USDA zone info for Ottumwa it's a good idea to figure out when it's possible 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.

Regal Geranium do ok in moderate cold which means that you can start planting them slightly earlier than other plants that might not handle the cold.

The earliest that you can plant regal geranium in Ottumwa is March. However, you really should wait until April 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. If you wait any later than that and your regal geranium may not have a chance to really do well. If you are starting your regal geranium indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

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

Since the USDA zone info for Ottumwa is not always accurate the actual date of last frost changes from year to year. Half of the time in Ottumwa there is a last frost after April 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 Ottumwa

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 Ottumwa

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