Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. 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 Sumner can be looked at to determine 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 are barely cold tolerant you can plant them just a tiny bit earlier in the year than other frost tender plants.

The earliest that you can plant watercress in Sumner 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

The average date of last frost is March 15 in Sumner. It might get as low as 15°F during the coldest months of winter.

Just be sure to remember that USDA zone info for Sumner is just an average and the actual date of last frost changes from year to year. Half of the time in Sumner there is a last frost after March 15 so always be ready to cover your watercress in the event of a surprise late frost.

USDA Zone Info for Sumner

Here is the info for USDA Zone 8b.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	15°F
Highest Expected Low	20°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 20°F.

Plants to Grow in Sumner

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