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

The USDA zone info for Watertown should be reffered to in order to estimate when it's a good idea to plant iberis.

Planting Calendar for Iberis

Frost tolerance for iberis:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Iberis are one of those plants that can tolerate a little bit of cold weather which means that you can get them planted earlier than plants that are more sensitive to the cold.

The earliest that you can plant iberis in Watertown 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 iberis and expect a good harvest is probably August. Any later than that and your iberis may not have a chance to fully mature. You can get started a little bit earlier by starting your iberis indoors.

Last Frost Date

On average all chance of frost has passed is on May 15 in Watertown. You can expect an average low temperature of -30°F in the coldest months of winter.

Always keep in mind that USDA zone info for Watertown is not always accurate and the actual date of last frost is different every year. Half of the time in Watertown you get surprised by a frost after May 15 so just be sure to be ready to protect your iberis in the event of a surprise late frost.

USDA Zone Info for Watertown

Here is the info for USDA Zone 4a.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-30°F
Highest Expected Low	-25°F

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

Plants to Grow in Watertown

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