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.

In Petaluma you can estimate when it's a good idea to plant bittercress by looking at the USDA zone info.

Planting Calendar for Bittercress

Frost tolerance for bittercress:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Bittercress can survive in very little cold which means that you can plant them just a tiny bit earlier in the year than more sensitive plants.

The earliest that you can plant bittercress in Petaluma 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 bittercress and expect a good harvest is probably September. Any later than that and your bittercress may not have a chance to fully mature. Starting your bittercress indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

In Petaluma the average date of last frost happens on February 15. You should expect an average low temperature of 25°F in the coldest months of winter.

Just be sure to remember that the actual date of last frost is just an average because it is based on the USDA zone info for Petaluma and it changes from year to year. Half of the time in Petaluma there is a last frost after February 15 so just be sure to be ready to protect your bittercress if you have a late frost.

USDA Zone Info for Petaluma

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 Petaluma

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