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

In Portland you can figure out when it's possible to plant california poppy by reviewing the USDA zone info.

Planting Calendar for California Poppy

Frost tolerance for california poppy:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

California Poppy do well in mild cold which means that you can plant them just a tiny bit earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant california poppy in Portland is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant california poppy and expect a good harvest is probably August. Any later than that and your california poppy may not have a chance to grow to maturity. If you are starting your california poppy indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

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

It's important to remember that USDA zone info for Portland is just an average and the actual date of last frost can change quite a bit from year to year. Half of the time in Portland last frost occurs after April 15 so make sure that you are prepared to protect your california poppy if you have one of those late frosts.

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.