Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In Knoxville you can estimate when you can plant watercress 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 ok in a tiny bit of cold which means that 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 Knoxville 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 couple of weeks earlier.

Last Frost Date

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

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

USDA Zone Info for Knoxville

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 Knoxville

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