One of the best tools that you have as gardeners to help us estimate 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 best time to plant common hollyhock in Oregon can be figured out by checking out the USDA zone info.

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 do well in moderate cold which tells us that you can plant them a little bit earlier in the year than more sensitive plants.

The earliest that you can plant common hollyhock in Oregon 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 grow to maturity. 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

On average the last frost is on April 15 in Oregon. It might get as low as -5°F during the coldest months of winter.

Always keep in mind that USDA zone info for Oregon is not always accurate and the actual date of last frost changes from year to year. Since half of the time in Oregon there is a last frost after April 15 be ready to cover your common hollyhock if you have one of those late frosts.

USDA Zone Info for Oregon

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in Oregon

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