One of the best tools that you have as gardeners to help us figure out your gardening schedule is the 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.

By reviewing the USDA zone info for Oelwein it's possible to figure out when it's a good idea to plant skullcap.

Planting Calendar for Skullcap

Frost tolerance for skullcap:	Not tolerant of frost.
When to plant:	After the last frost.

Skullcap require warm weather which means that it is necessary to wait until it warms up after the last frost before you can plant them.

The earliest that you can plant skullcap 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 skullcap and expect a good harvest is probably August. If you wait any later than that and your skullcap may not have a chance to fully mature. You can get started a few weeks earlier by starting your skullcap indoors.

Last Frost Date

On average all chance of frost has passed is on April 15 in Oelwein. In the coldest months of winter you should expect an average low temperature of -20°F.

Just be sure to remember that USDA zone info for Oelwein is not always accurate and the actual date of last frost is different every year. Since half of the time in Oelwein you get surprised by a frost after April 15 be ready to protect your skullcap if you have 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.