One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Tualatin should be reffered to in order to figure out when to plant common hollyhock.

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 can survive in some cold which tells us that you can plant them a little bit earlier in the year than other plants that might not handle the cold.

The earliest that you can plant common hollyhock in Tualatin 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. Any later than that and your common hollyhock may not have a chance to really do well. You can get started a few weeks earlier by starting your common hollyhock indoors.

Last Frost Date

In Tualatin the average date of last frost happens on March 15. You can expect an average low temperature of 15°F in the coldest months of winter.

Keep in mind that USDA zone info for Tualatin is an average and the actual date of last frost is different every year. Since half of the time in Tualatin there is a last frost after March 15 be ready to cover your common hollyhock in the event of a surprise late frost.

USDA Zone Info for Tualatin

Here is the info for USDA Zone 8b.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	15°F
Highest Expected Low	20°F

This means that on a really cold year, the coldest it will get is 15°F. On most years you should be prepared to experience lows near 20°F.

Plants to Grow in Tualatin

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