Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A common way of figuring out when it's possible to plant common hollyhock is to refer to the USDA zone info for Lake Oswego.

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 a little bit earlier in the year because they do well in moderate cold.

The earliest that you can plant common hollyhock in Lake Oswego 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. If you wait any later than that and 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 little bit earlier.

Last Frost Date

The average date of last frost is March 15 in Lake Oswego. In the coldest months of winter you can expect an average low temperature of 15°F.

Since the USDA zone info for Lake Oswego is just an average the actual date of last frost changes from year to year. Half of the time in Lake Oswego it frosts late in the year after March 15 so make sure that you are ready to cover your common hollyhock in the event of a late frost.

USDA Zone Info for Lake Oswego

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 Lake Oswego

You may be interested in your other planting guides for Lake Oswego.