The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. 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 Portland should be used to determine when it's possible to plant hemerocallis.

Planting Calendar for Hemerocallis

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

You can plant hemerocallis just a bit earlier in the year because they are one of those plants that can tolerate a little bit of cold weather.

The earliest that you can plant hemerocallis 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 hemerocallis and expect a good harvest is probably September. Any later than that and your hemerocallis may not have a chance to grow to maturity. If you are starting your hemerocallis 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 April 15 in Portland. It might get as low as -15°F during the coldest months of winter.

Since the USDA zone info for Portland may not be accurate from year to year the actual date of last frost changes from year to year. Since half of the time in Portland there is a last frost after April 15 be ready to cover your hemerocallis in the event of a surprise late frost.

USDA Zone Info for Portland

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-15°F
Highest Expected Low	-10°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 -10°F.

Plants to Grow in Portland

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