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 estimating when it's a good idea to plant hollyhocks is to examine the USDA zone info for Lake Oswego.

Planting Calendar for Hollyhocks

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

Hollyhocks do ok in a little bit of cold which means that you can plant them just a bit earlier in the year than more sensitive plants.

The earliest that you can plant hollyhocks 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 hollyhocks and expect a good harvest is probably September. If you wait any later than that and your hollyhocks may not have a chance to grow to maturity. If you are starting your hollyhocks indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

On average all chance of frost has passed is on March 15 in Lake Oswego. You can expect an average low temperature of 15°F in the coldest months of winter.

Since the USDA zone info for Lake Oswego is not always accurate the actual date of last frost can change quite a bit from year to year. Since half of the time in Lake Oswego you get a frost after March 15 be ready to cover your hollyhocks if you have a surprise 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.