One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

A way of estimating when it's the best time to plant hollyhocks is to use the USDA zone info for Portland.

Planting Calendar for Hollyhocks

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

You can plant hollyhocks a little earlier in the year because they do well in moderate cold.

The earliest that you can plant hollyhocks in Portland 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. Any later than that and your hollyhocks may not have a chance to really do well. You can get started a couple of weeks earlier by starting your hollyhocks indoors.

Last Frost Date

The average date of last frost is March 15 in Portland. You can expect an average low temperature of 15°F in the coldest months of winter.

Always keep in mind that USDA zone info for Portland is just an average and the actual date of last frost will vary from year to year. Since half of the time in Portland you get a frost after March 15 be ready to cover your hollyhocks if you have a late frost.

USDA Zone Info for Portland

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 Portland

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