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.

You can figure out when to plant watercress in Alvin by looking at 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 are barely cold tolerant which tells us that you can plant them slightly earlier than other frost tender plants.

The earliest that you can plant watercress in Alvin is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant watercress and expect a good harvest is probably September. You probably don't want to wait any later than that or else your watercress may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your watercress indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on February 15 in Alvin. You should expect an average low temperature of 20°F in the coldest months of winter.

Since the USDA zone info for Alvin is just an average the actual date of last frost changes from year to year. Since half of the time in Alvin you get surprised by a frost after February 15 be ready to cover your watercress if you have a surprise late frost.

USDA Zone Info for Alvin

Here is the info for USDA Zone 9a.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	20°F
Highest Expected Low	25°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 25°F.

Plants to Grow in Alvin

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