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.

The best time to plant watercress in Hillsboro should be figured out by checking out 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.

Watercress do well in some cold which means that you can plant them slightly earlier in the year than more sensitive plants.

The earliest that you can plant watercress in Hillsboro 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. If you wait any later than that and your watercress may not have a chance to grow to maturity. You can get started a little bit earlier by starting your watercress indoors.

Last Frost Date

In Hillsboro the average date of last frost happens on April 15. You should expect an average low temperature of -10°F in the coldest months of winter.

Since the USDA zone info for Hillsboro is not always accurate the actual date of last frost will vary from year to year. Half of the time in Hillsboro last frost occurs after April 15 so make sure that you are prepared to protect your watercress if you have a late frost.

USDA Zone Info for Hillsboro

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 Hillsboro

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