When can I plant Iberis in Zone 4b

The USDA Zone info is a great tool for gardeners to help us estimate our gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for our area.

You will be able to estimate when it's a good idea to plant iberis by checking out the USDA zone info for Zone 4b.


Planting Calendar for Iberis

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

Since iberis are moderately cold tolerant you can plant them a little bit earlier in the year than other frost tender plants.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant iberis
Possibly ok, but a risky time to plant iberis
Probably not a good time to plant iberis

The earliest that you can plant iberis in Zone 4b 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. You probably don't want to wait any later than that or else your iberis may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your iberis indoors.

Last Frost Date

In Zone 4b the average date of last frost happens on May 15. In the coldest months of winter we can expect an average low temperature of -25°F.

Remember that our actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Zone 4b and it can change quite a bit from year to year. Since half of the time in Zone 4b we get surprised by a frost after May 15 be ready to cover your iberis in the event of a late frost.

USDA Zone Info for Zone 4b

Here is the info for USDA Zone 4b.

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

Plants to Grow in Zone 4b

You may be interested in our other planting guides for Zone 4b.