One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The first chance to plant blue throatwort in Oelwein should be determined by looking at the USDA zone info.

Planting Calendar for Blue Throatwort

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

It's not a good idea to plant blue throatwort until after the last frost because they do not do well in cold weather.

The earliest that you can plant blue throatwort in Oelwein 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 blue throatwort and expect a good harvest is probably August. Any later than that and your blue throatwort may not have a chance to really do well. You can get started a few weeks earlier by starting your blue throatwort indoors.

Last Frost Date

The average date of last frost is April 15 in Oelwein. In the coldest months of winter you should expect an average low temperature of -20°F.

Keep in mind that USDA zone info for Oelwein is just an average and the actual date of last frost changes from year to year. Half of the time in Oelwein you get a frost after April 15 so always be ready to cover your blue throatwort in the event of one of those late frosts.

USDA Zone Info for Oelwein

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 Oelwein

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