One of the first steps you take when you are getting a good idea your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

A common way of getting a good idea when it's possible to plant iresene is to look at the USDA zone info for Ottumwa.

Planting Calendar for Iresene

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

Iresene require warm weather which means that you need to wait until it warms up after the last frost has passed before you can plant them.

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

Last Frost Date

In Ottumwa the average date of last frost happens on April 15. It might get as low as -15°F during the coldest months of winter.

Since the USDA zone info for Ottumwa is not always accurate the actual date of last frost can change quite a bit from year to year. Half of the time in Ottumwa you get surprised by a frost after April 15 so always be ready to protect your iresene if you have a surprise late frost.

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.