One of the first steps you take when you are determining your gardening schedule is find your 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.

By referring to the USDA zone info for Tucson it's possible to figure out when it's the best time 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.

Pennyroyal can survive in pretty solid cold which tells us that you can plant them much earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant pennyroyal in Tucson 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. Any later than that and your pennyroyal may not have a chance to fully mature. You can get started a few weeks earlier by starting your pennyroyal indoors.

Last Frost Date

In Tucson the average date of last frost happens on February 15. 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 Tucson and it can change quite a bit from year to year. Half of the time in Tucson there is a last frost after February 15 so be sure to be ready to cover your pennyroyal if you have one of those late frosts.

USDA Zone Info for Tucson

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 Tucson

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