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

The USDA zone info for San Luis Obispo should be looked at to determine when you can plant calendula.

Planting Calendar for Calendula

Frost tolerance for calendula:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

You can plant calendula a bit earlier in the year because they are one of those plants that can tolerate a little bit of cold weather.

The earliest that you can plant calendula in San Luis Obispo 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 calendula and expect a good harvest is probably October. If you wait any later than that and your calendula may not have a chance to fully mature. Starting your calendula indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

The average date of last frost is February 15 in San Luis Obispo. In the coldest months of winter you should expect an average low temperature of 25°F.

It's important to remember that USDA zone info for San Luis Obispo may not be accurate from year to year and the actual date of last frost will vary from year to year. Since half of the time in San Luis Obispo you get a frost after February 15 be ready to protect your calendula if you have one of those late frosts.

USDA Zone Info for San Luis Obispo

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 San Luis Obispo

You may be interested in your other planting guides for San Luis Obispo.