One of the first steps you take when you are determining your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You can figure out when it's the best time to plant pennyroyal in Ypsilanti 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 do well in cold you can plant them earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant pennyroyal in Ypsilanti 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. Any later than that and your pennyroyal may not have a chance to grow to maturity. You can get started a little bit earlier by starting your pennyroyal indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Ypsilanti. You should expect an average low temperature of -10°F in the coldest months of winter.

Since the USDA zone info for Ypsilanti may not be accurate from year to year the actual date of last frost can change quite a bit from year to year. Half of the time in Ypsilanti it frosts late in the year after April 15 so make sure that you are ready to protect your pennyroyal if you have one of those late frosts.

USDA Zone Info for Ypsilanti

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Ypsilanti

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