One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You will be able to figure out when it's possible to plant pennyroyal by using the USDA zone info for Highland.

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 a lot 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 Highland is January. However, you really should wait until February if you don't want to take any chances.

The last month that you can plant pennyroyal and expect a good harvest is probably October. If you wait any later than that and your pennyroyal may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your pennyroyal indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on February 15 in Highland. In the coldest months of winter you should expect an average low temperature of 25°F.

Keep in mind that the actual date of last frost is just an average because it is based on the USDA zone info for Highland and it can change quite a bit from year to year. Since half of the time in Highland you get surprised by a frost after February 15 be ready to protect your pennyroyal in the event of a surprise late frost.

USDA Zone Info for Highland

Here is the info for USDA Zone 9b.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	25°F
Highest Expected Low	30°F

This means that on a really cold year, the coldest it will get is 25°F. On most years you should be prepared to experience lows near 30°F.

Plants to Grow in Highland

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