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

The USDA zone info for Aspen can be reviewed to estimate when you can 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 can survive in mild cold which means that you can plant them just a bit earlier in the year than more sensitive plants.

The earliest that you can plant iberis in Aspen 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 couple of weeks earlier.

Last Frost Date

On average the last frost is on April 15 in Aspen. In the coldest months of winter you should expect an average low temperature of -15°F.

Since the USDA zone info for Aspen is not always accurate the actual date of last frost is different every year. Half of the time in Aspen it frosts late in the year after April 15 so make sure that you are prepared to protect your iberis in the event of one of those late frosts.

USDA Zone Info for Aspen

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 Aspen

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