One of the best tools that you have as gardeners to help us determine your gardening schedule is the 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.

A way of determining when it's a good idea to plant watercress is to look at the USDA zone info for Ione.

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 get them planted just a bit earlier than more sensitive plants.

The earliest that you can plant watercress in Ione 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. If you wait any later than that and your watercress may not have a chance to really do well. You can get started a couple of weeks earlier by starting your watercress indoors.

Last Frost Date

On average the last frost is on February 15 in Ione. You can expect an average low temperature of 25°F in the coldest months of winter.

It's important to remember that USDA zone info for Ione may not be accurate from year to year and the actual date of last frost can change quite a bit from year to year. Half of the time in Ione it frosts late in the year after February 15 so always be ready to cover your watercress if you have a late frost.

USDA Zone Info for Ione

Here is the info for USDA Zone 9b.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	25°F
Highest Expected Low	30°F

This means that on a really cold year, the coldest it will get is 25°F. On most years you should be prepared to experience lows near 30°F.

Plants to Grow in Ione

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