One of the first steps you take when you are getting a good idea your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

You can estimate when to plant watercress in Columbia by referring to 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 very little cold which means that you can plant them a bit earlier in the year than more sensitive plants.

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

Last Frost Date

In Columbia the average date of last frost happens on April 15. You should expect an average low temperature of -5°F in the coldest months of winter.

It's important to remember that USDA zone info for Columbia is just an average and the actual date of last frost can change quite a bit from year to year. Half of the time in Columbia 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 Columbia

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in Columbia

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