The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

You can figure out when you can plant watercress in Hermiston by using 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 are barely cold tolerant 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 Hermiston 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 grow to maturity. Starting your watercress indoors is a great way to get them started a little bit earlier.

Last Frost Date

In Hermiston the average date of last frost happens on April 15. In the coldest months of winter you can expect an average low temperature of 0°F.

Always keep in mind that the actual date of last frost is not always accurate because it is based on the USDA zone info for Hermiston and it is different every year. Since half of the time in Hermiston you get a frost after April 15 be ready to cover your watercress in the event of one of those late frosts.

USDA Zone Info for Hermiston

Here is the info for USDA Zone 7a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	0°F
Highest Expected Low	5°F

This means that on a really cold year, the coldest it will get is 0°F. On most years you should be prepared to experience lows near 5°F.

Plants to Grow in Hermiston

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