When to Plant Pennyroyal in River Grove, IL

The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In River Grove you can estimate when it's the best time to 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.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant pennyroyal
Possibly ok, but a risky time to plant pennyroyal
Probably not a good time to plant pennyroyal

The earliest that you can plant pennyroyal in River Grove 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. If you wait any later than that and your pennyroyal may not have a chance to really do well. Starting your pennyroyal indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average the last frost is on April 15 in River Grove. You should expect an average low temperature of -15°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 River Grove and it can change quite a bit from year to year. Half of the time in River Grove last frost occurs after April 15 so make sure that you are ready to cover your pennyroyal if you have one of those late frosts.

USDA Zone Info for River Grove

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 River Grove

You may be interested in your other planting guides for River Grove.