One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A way of figuring out when you can plant watercress is to check out the USDA zone info for Zion.

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.

Watercress do ok in moderate cold which means that you can plant them slightly earlier than other plants that might not handle the cold.

The earliest that you can plant watercress in Zion 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. You probably don't want to wait any later than that or else your watercress may not have a chance to fully mature. Starting your watercress indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Zion. In the coldest months of winter you can expect an average low temperature of -15°F.

Keep in mind that USDA zone info for Zion is just an average and the actual date of last frost is different every year. Half of the time in Zion you get surprised by a frost after April 15 so make sure that you are prepared to protect your watercress in the event of one of those late frosts.

USDA Zone Info for Zion

Here is the info for USDA Zone 5b.

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

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Zion

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