The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Princeton you can determine when it's the best time to plant iberis by checking out the USDA zone info.

Planting Calendar for Iberis

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

Iberis can survive in some cold which means that you can plant them a little earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant iberis in Princeton 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 really do well. If you are starting your iberis indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

In Princeton the average date of last frost happens on May 15. You can expect an average low temperature of -30°F in the coldest months of winter.

Since the USDA zone info for Princeton is not always accurate the actual date of last frost will vary from year to year. Half of the time in Princeton there is a last frost after May 15 so make sure that you are prepared to cover your iberis if you have one of those late frosts.

USDA Zone Info for Princeton

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 Princeton

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