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.

In Mammoth Lakes you can estimate when you can plant watercress by looking at the USDA zone info.

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 just a tiny bit earlier in the year than other plants that might not handle the cold.

The earliest that you can plant watercress in Mammoth Lakes 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 watercress and expect a good harvest is probably August. Any later than that and your watercress may not have a chance to really do well. Starting your watercress indoors is a great way to get them started a few weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Mammoth Lakes. In the coldest months of winter you can expect an average low temperature of -10°F.

Since the USDA zone info for Mammoth Lakes is just an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Mammoth Lakes there is a last frost after April 15 be ready to protect your watercress in the event of a surprise late frost.

USDA Zone Info for Mammoth Lakes

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Mammoth Lakes

You may be interested in your other planting guides for Mammoth Lakes.