One of the first steps you take when you are making a decision about your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Gardena can be reffered to in order to figure out when it's possible to plant watercress.

Planting Calendar for Watercress

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

Since watercress do ok in moderate cold you can plant them a bit earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant watercress in Gardena 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 watercress and expect a good harvest is probably September. If you wait any later than that and your watercress may not have a chance to grow to maturity. If you are starting your watercress indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

On average the last frost has passed is on January 31 in Gardena. In the coldest months of winter you should expect an average low temperature of 35°F.

Since the USDA zone info for Gardena may not be accurate from year to year the actual date of last frost can change quite a bit from year to year. Since half of the time in Gardena it frosts late in the year after January 31 be ready to cover your watercress if you have a surprise late frost.

USDA Zone Info for Gardena

Here is the info for USDA Zone 10b.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	35°F
Highest Expected Low	40°F

This means that on a really cold year, the coldest it will get is 35°F. On most years you should be prepared to experience lows near 40°F.

Plants to Grow in Gardena

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