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

In Grass Valley you can estimate when it's the best time to plant hollyhocks by referring to 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 well in moderate 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 hollyhocks in Grass Valley 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. You probably don't want to wait any later than that or else your hollyhocks may not have a chance to really do well. You can get started a couple of weeks earlier by starting your hollyhocks indoors.

Last Frost Date

The average date of last frost is February 15 in Grass Valley. It might get as low as 20°F during the coldest months of winter.

Since the USDA zone info for Grass Valley may not be accurate from year to year the actual date of last frost will vary from year to year. Half of the time in Grass Valley last frost occurs after February 15 so make sure that you are prepared to protect your hollyhocks if you have a surprise late frost.

USDA Zone Info for Grass Valley

Here is the info for USDA Zone 9a.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	20°F
Highest Expected Low	25°F

This means that on a really cold year, the coldest it will get is 20°F. On most years you should be prepared to experience lows near 25°F.

Plants to Grow in Grass Valley

You may be interested in your other planting guides for Grass Valley.