Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Ankeny you can determine when you can plant pennyroyal by looking at the USDA zone info.

Planting Calendar for Pennyroyal

Frost tolerance for pennyroyal:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

You can plant pennyroyal earlier in the year because they are one of those plants that can tolerate quite a bit of cold weather.

The earliest that you can plant pennyroyal in Ankeny is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant pennyroyal and expect a good harvest is probably September. You probably don't want to wait any later than that or else your pennyroyal may not have a chance to really do well. If you are starting your pennyroyal indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

In Ankeny the average date of last frost happens on April 15. You can expect an average low temperature of -20°F in the coldest months of winter.

Keep in mind that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Ankeny and it will vary from year to year. Since half of the time in Ankeny it frosts late in the year after April 15 be ready to protect your pennyroyal if you have a late frost.

USDA Zone Info for Ankeny

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 Ankeny

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