Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The USDA zone info for Mount Washington should be used to figure out when it's a good idea to plant pennyroyal.

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 do well in cold.

The earliest that you can plant pennyroyal in Mount Washington 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 grow to maturity. Starting your pennyroyal indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

In Mount Washington the average date of last frost happens on April 15. In the coldest months of winter you should expect an average low temperature of -5°F.

Always keep in mind that USDA zone info for Mount Washington is not always accurate and the actual date of last frost can change quite a bit from year to year. Half of the time in Mount Washington you get a frost after April 15 so always be ready to protect your pennyroyal in the event of a surprise late frost.

USDA Zone Info for Mount Washington

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 Low	0°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 Mount Washington

You may be interested in your other planting guides for Mount Washington.