Before planting it is a good idea to find your USDA Zone info to determine 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.

You should be able to estimate when to plant pennyroyal by referring to the USDA zone info for Calexico.

Planting Calendar for Pennyroyal

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

Since pennyroyal are one of those plants that can tolerate quite a bit of cold weather you can plant them a lot earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant pennyroyal in Calexico 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. If you are starting your pennyroyal indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

On average the last frost has passed is on January 31 in Calexico. In the coldest months of winter you can expect an average low temperature of 30°F.

It's important to remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Calexico and it changes from year to year. Since half of the time in Calexico it frosts late in the year after January 31 be ready to protect your pennyroyal if you have one of those late frosts.

USDA Zone Info for Calexico

Here is the info for USDA Zone 10a.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	30°F
Highest Expected Low	35°F

This means that on a really cold year, the coldest it will get is 30°F. On most years you should be prepared to experience lows near 35°F.

Plants to Grow in Calexico

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