One of the best tools that you have as gardeners to help us determine 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.

By checking out the USDA zone info for Portland you should be able to determine when it's the best time to plant strawflowers.

Planting Calendar for Strawflowers

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

Strawflowers do well in mild cold which tells us that you can plant them a bit earlier in the year than more sensitive plants.

The earliest that you can plant strawflowers 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 strawflowers and expect a good harvest is probably August. If you wait any later than that and your strawflowers may not have a chance to fully mature. You can get started a little bit earlier by starting your strawflowers indoors.

Last Frost Date

On average the last frost has passed is on April 15 in Portland. You should expect an average low temperature of -15°F in the coldest months of winter.

Just be sure to remember that the actual date of last frost is an average because it is based on the USDA zone info for Portland and it will vary from year to year. Since half of the time in Portland you get a frost after April 15 be ready to protect your strawflowers 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.