The USDA Zone info is a great tool for gardeners to help us determine 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.

The USDA zone info for Napa can be looked at to figure out when it's a good idea to plant bells of ireland.

Planting Calendar for Bells of Ireland

Frost tolerance for bells of ireland:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

You can plant bells of ireland slightly earlier in the year because they do ok in moderate cold.

The earliest that you can plant bells of ireland in Napa 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 bells of ireland and expect a good harvest is probably September. You probably don't want to wait any later than that or else your bells of ireland may not have a chance to grow to maturity. Starting your bells of ireland indoors is a great way to get them started a few weeks earlier.

Last Frost Date

The average date of last frost is February 15 in Napa. It might get as low as 25°F during the coldest months of winter.

Since the USDA zone info for Napa is not always accurate the actual date of last frost will vary from year to year. Half of the time in Napa there is a last frost after February 15 so just be sure to be ready to cover your bells of ireland in the event of a late frost.

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.