Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

One way of figuring out when you can plant garden cress is to consult the USDA zone info for Petaluma.

Planting Calendar for Garden cress

Frost tolerance for garden cress:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

Garden cress do not do well in cold weather which means that it's necessary to wait until it warms up after all chance of frost has passed before you can plant them.

The earliest that you can plant garden cress in Petaluma is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant garden cress and expect a good harvest is probably September. You probably don't want to wait any later than that or else your garden cress may not have a chance to fully mature. If you are starting your garden cress indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

On average the last frost has passed is on February 15 in Petaluma. You should expect an average low temperature of 25°F in the coldest months of winter.

Since the USDA zone info for Petaluma is an average the actual date of last frost will vary from year to year. Half of the time in Petaluma you get a frost after February 15 so always be ready to protect your garden cress in the event of one of those late frosts.

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.