One of the first steps you take when you are getting a good idea your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Napa you can determine when to plant hollyhocks by using the USDA zone info.

Planting Calendar for Hollyhocks

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

Hollyhocks do ok in a little bit of cold which means that you can plant them a bit earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant hollyhocks 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 hollyhocks and expect a good harvest is probably October. If you wait any later than that and your hollyhocks may not have a chance to fully mature. If you are starting your hollyhocks indoors then you might be able to get away with starting them a couple of weeks earlier.

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 is not always accurate the actual date of last frost will vary from year to year. Half of the time in Napa it frosts late in the year after February 15 so make sure that you are prepared to cover your hollyhocks if you have a surprise 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.