Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You should be able to estimate when to plant iberis by using the USDA zone info for Urbana.

Planting Calendar for Iberis

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

Iberis are moderately cold tolerant which means that you can get them planted earlier than more sensitive plants.

The earliest that you can plant iberis in Urbana 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 iberis and expect a good harvest is probably September. You probably don't want to wait any later than that or else 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 Urbana the average date of last frost happens on April 15. It might get as low as -15°F during the coldest months of winter.

Keep in mind that USDA zone info for Urbana may not be accurate from year to year and the actual date of last frost is different every year. Half of the time in Urbana you get surprised by a frost after April 15 so just be sure to be ready to cover your iberis in the event of a surprise late frost.

USDA Zone Info for Urbana

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-15°F
Highest Expected Low	-10°F

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Urbana

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