Before planting it is a good idea to find your USDA Zone info to figure out 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 figure out when it's a good idea to plant rosemary by referring to the USDA zone info for El Cajon.

Planting Calendar for Rosemary

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

Rosemary are one of those plants that can tolerate quite a bit of cold weather which tells us that you can plant them much earlier than plants that are more sensitive to the cold.

The earliest that you can plant rosemary in El Cajon 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 rosemary and expect a good harvest is probably October. Any later than that and your rosemary may not have a chance to really do well. You can get started a couple of weeks earlier by starting your rosemary indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on January 31 in El Cajon. You should expect an average low temperature of 30°F in the coldest months of winter.

Just be sure to remember that the actual date of last frost is an average because it is based on the USDA zone info for El Cajon and it changes from year to year. Since half of the time in El Cajon you get a frost after January 31 be ready to protect your rosemary in the event of a late frost.

USDA Zone Info for El Cajon

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 El Cajon

You may be interested in your other planting guides for El Cajon.