One of the best tools that you have as gardeners to help us determine 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 earliest that you can plant bishop's weed in San Luis Obispo should be determined by reviewing the USDA zone info.

Planting Calendar for Bishop's Weed

Frost tolerance for bishop's weed:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Bishop's Weed are very cold tolerant which tells us that you can start planting them much earlier than other frost tender plants.

The earliest that you can plant bishop's weed 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 bishop's weed and expect a good harvest is probably October. If you wait any later than that and your bishop's weed may not have a chance to grow to maturity. You can get started a few weeks earlier by starting your bishop's weed indoors.

Last Frost Date

On average the last frost is on February 15 in San Luis Obispo. It might get as low as 25°F during the coldest months of winter.

Since the USDA zone info for San Luis Obispo is not always accurate the actual date of last frost can change quite a bit from year to year. Half of the time in San Luis Obispo it frosts late in the year after February 15 so always be ready to protect your bishop's weed 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.