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

A way of estimating when it's a good idea to plant iberis is to check out the USDA zone info for Waterloo.

Planting Calendar for Iberis

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

Iberis do well in moderate cold which tells us that you can plant them just a bit earlier in the year than plants that are more sensitive to the cold.

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

Last Frost Date

The average date of last frost is April 15 in Waterloo. In the coldest months of winter you can expect an average low temperature of -10°F.

Remember that USDA zone info for Waterloo may not be accurate from year to year and the actual date of last frost will vary from year to year. Since half of the time in Waterloo you get surprised by a frost after April 15 be ready to cover your iberis if you have a surprise late frost.

USDA Zone Info for Waterloo

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Waterloo

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