One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

One way of figuring out when it's a good idea to plant common hollyhock is to consult the USDA zone info for Henderson.

Planting Calendar for Common hollyhock

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

Common hollyhock are moderately cold tolerant which means that you can plant them earlier than other frost tender plants.

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

Last Frost Date

In Henderson the average date of last frost happens on February 15. In the coldest months of winter you can expect an average low temperature of 20°F.

It's important to remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Henderson and it can change quite a bit from year to year. Half of the time in Henderson there is a last frost after February 15 so just be sure to be ready to cover your common hollyhock if you have a surprise late frost.

USDA Zone Info for Henderson

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 Henderson

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