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.

By checking out the USDA zone info for Hummelstown you will be able to figure out when it's the best time 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.

Watercress do ok in mild cold which tells us that you can plant them slightly earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant watercress in Hummelstown 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. Any later than that and your watercress may not have a chance to really do well. You can get started a little bit earlier by starting your watercress indoors.

Last Frost Date

In Hummelstown 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.

Remember that USDA zone info for Hummelstown is not always accurate and the actual date of last frost will vary from year to year. Half of the time in Hummelstown it frosts late in the year after April 15 so always be ready to cover your watercress if you have a surprise late frost.

USDA Zone Info for Hummelstown

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 Hummelstown

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