When to Plant Pennyroyal in Flat Rock, MI

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.

The first opportunity to plant pennyroyal in Flat Rock can be figured out by reviewing 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.

Since pennyroyal are very cold tolerant you can plant them a lot earlier in the year than more sensitive plants.

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 Flat Rock 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 grow to maturity. 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

The average date of last frost is April 15 in Flat Rock. It might get as low as -5°F during the coldest months of winter.

Always keep in mind that USDA zone info for Flat Rock is not always accurate and the actual date of last frost will vary from year to year. Since half of the time in Flat Rock there is a last frost after April 15 be ready to cover your pennyroyal if you have a late frost.

USDA Zone Info for Flat Rock

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)April 15
Average Date of First Frost (fall)October 15
Lowest Expected Low-5°F
Highest Expected Low0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in Flat Rock

You may be interested in your other planting guides for Flat Rock.