Before planting it is a good idea to find your USDA Zone info to determine 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.

A common way of determining when to plant watercress is to examine the USDA zone info for Marion.

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 Marion 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 grow to maturity. If you are starting your watercress indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on March 15 in Marion. It might get as low as 10°F during the coldest months of winter.

Just be sure to remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Marion and it will vary from year to year. Half of the time in Marion there is a last frost after March 15 so make sure that you are prepared to cover your watercress in the event of a surprise late frost.

USDA Zone Info for Marion

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°F

This means that on a really cold year, the coldest it will get is 10°F. On most years you should be prepared to experience lows near 15°F.

Plants to Grow in Marion

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