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.

The best time to plant garden cress in Napa can be determined by using the USDA zone info.

Planting Calendar for Garden cress

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

Garden cress are not cold tolerant which tells us that you really should wait until it warms up after the last frost before you can plant them.

The earliest that you can plant garden cress in Napa 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. Any later than that and your garden cress may not have a chance to grow to maturity. 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 all chance of frost has passed is on February 15 in Napa. You can expect an average low temperature of 25°F in the coldest months of winter.

Keep in mind that the actual date of last frost is not always accurate because it is based on the USDA zone info for Napa and it can change quite a bit from year to year. Since half of the time in Napa you get a frost after February 15 be ready to protect your garden cress in the event of one of those late frosts.

USDA Zone Info for Napa

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 Napa

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