One of the best tools that you have as gardeners to help us estimate 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.

A common way of estimating when you can plant pennyroyal is to refer to the USDA zone info for Pasadena.

Planting Calendar for Pennyroyal

Frost tolerance for pennyroyal:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Pennyroyal do well in cold weather which tells us that you can plant them much earlier in the year than other plants that might not handle the cold.

The earliest that you can plant pennyroyal in Pasadena 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 really do well. You can get started a little bit earlier by starting your pennyroyal indoors.

Last Frost Date

In Pasadena the average date of last frost happens on February 15. You can expect an average low temperature of 20°F in the coldest months of winter.

Remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Pasadena and it will vary from year to year. Half of the time in Pasadena you get surprised by a frost after February 15 so be sure to be ready to protect your pennyroyal if you have a late frost.

USDA Zone Info for Pasadena

Here is the info for USDA Zone 9a.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	20°F
Highest Expected Low	25°F

This means that on a really cold year, the coldest it will get is 20°F. On most years you should be prepared to experience lows near 25°F.

Plants to Grow in Pasadena

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