One of the first steps you take when you are estimating 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.

One way of making a decision about when to plant rosemary is to use the USDA zone info for California.

Planting Calendar for Rosemary

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

Since rosemary do well in cold you can plant them much earlier in the year than other plants that might not handle the cold.

The earliest that you can plant rosemary in California is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant rosemary and expect a good harvest is probably September. Any later than that and your rosemary may not have a chance to grow to maturity. You can get started a few weeks earlier by starting your rosemary indoors.

Last Frost Date

The average date of last frost is April 15 in California. In the coldest months of winter you should expect an average low temperature of -5°F.

Since the USDA zone info for California is an average the actual date of last frost can change quite a bit from year to year. Since half of the time in California you get a frost after April 15 be ready to cover your rosemary in the event of a late frost.

USDA Zone Info for California

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in California

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