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.

A common way of figuring out when it's a good idea to plant iberis is to look at the USDA zone info for Napa.

Planting Calendar for Iberis

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

Iberis do ok in a little bit of cold which tells us that you can plant them a little bit earlier in the year than other frost tender plants.

The earliest that you can plant iberis in Napa is January. However, you really should wait until February if you don't want to take any chances.

The last month that you can plant iberis and expect a good harvest is probably October. You probably don't want to wait any later than that or else your iberis may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your iberis indoors.

Last Frost Date

In Napa the average date of last frost happens on February 15. In the coldest months of winter you can expect an average low temperature of 25°F.

Since the USDA zone info for Napa may not be accurate from year to year the actual date of last frost changes from year to year. Since half of the time in Napa you get a frost after February 15 be ready to protect your iberis if you have one of those late frosts.

USDA Zone Info for Napa

Here is the info for USDA Zone 9b.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	25°F
Highest Expected Low	30°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 30°F.

Plants to Grow in Napa

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