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.

You should be able to estimate when to plant common hollyhock by referring to the USDA zone info for Sterling.

Planting Calendar for Common hollyhock

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

You can plant common hollyhock just a bit earlier in the year because they are one of those plants that can tolerate a little bit of cold weather.

The earliest that you can plant common hollyhock in Sterling 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 common hollyhock and expect a good harvest is probably September. You probably don't want to wait any later than that or else your common hollyhock may not have a chance to really do well. Starting your common hollyhock indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

In Sterling the average date of last frost happens on April 15. It might get as low as -20°F during the coldest months of winter.

Since the USDA zone info for Sterling is not always accurate the actual date of last frost is different every year. Half of the time in Sterling there is a last frost after April 15 so always be ready to protect your common hollyhock if you have one of those late frosts.

USDA Zone Info for Sterling

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°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 -15°F.

Plants to Grow in Sterling

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