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 Oshkosh you can determine when it's a good idea to 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 well in some cold which tells us that you can plant them a bit earlier in the year than more sensitive plants.

The earliest that you can plant watercress in Oshkosh 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. Starting your watercress indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average the last frost has passed is on April 15 in Oshkosh. It might get as low as -20°F during the coldest months of winter.

It's important to remember that the actual date of last frost is just an average because it is based on the USDA zone info for Oshkosh and it will vary from year to year. Since half of the time in Oshkosh it frosts late in the year after April 15 be ready to protect your watercress in the event of one of those late frosts.

USDA Zone Info for Oshkosh

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Oshkosh

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