The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

One way of determining when you can plant california poppy is to examine the USDA zone info for Portland.

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 are barely cold tolerant which tells us that you can start planting them slightly earlier than other plants that might not handle 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. If you wait 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

The average date of last frost is 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 is just an average the actual date of last frost is different every year. Since half of the time in Portland you get surprised by a frost after April 15 be ready to protect your california poppy if you have a 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.