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

The best time to plant scarlet pimpernels in Portland should be determined by checking out the USDA zone info.

Planting Calendar for Scarlet Pimpernels

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

Scarlet Pimpernels do ok in some cold which tells us that you can plant them slightly earlier in the year than other plants that might not handle the cold.

The earliest that you can plant scarlet pimpernels 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 scarlet pimpernels and expect a good harvest is probably August. You probably don't want to wait any later than that or else your scarlet pimpernels may not have a chance to grow to maturity. If you are starting your scarlet pimpernels indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

In Portland the average date of last frost happens on April 15. It might get as low as 0°F during the coldest months of winter.

Since the USDA zone info for Portland is just an average the actual date of last frost changes from year to year. Half of the time in Portland last frost occurs after April 15 so make sure that you are ready to cover your scarlet pimpernels if you have a surprise late frost.

USDA Zone Info for Portland

Here is the info for USDA Zone 7a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	0°F
Highest Expected Low	5°F

This means that on a really cold year, the coldest it will get is 0°F. On most years you should be prepared to experience lows near 5°F.

Plants to Grow in Portland

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