When to Plant Primula in Happy Valley, OR

Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The first opportunity to plant primula in Happy Valley should be determined by reviewing the USDA zone info.


Planting Calendar for Primula

Frost tolerance for primula: Very tolerant of frost.
When to plant: Up to 7 weeks before last frost.

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

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant primula
Possibly ok, but a risky time to plant primula
Probably not a good time to plant primula

The earliest that you can plant primula in Happy Valley 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 primula and expect a good harvest is probably September. If you wait any later than that and your primula may not have a chance to really do well. If you are starting your primula indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

The average date of last frost is March 15 in Happy Valley. In the coldest months of winter you can expect an average low temperature of 15°F.

Since the USDA zone info for Happy Valley 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 Happy Valley you get a frost after March 15 be ready to protect your primula in the event of a late frost.

USDA Zone Info for Happy Valley

Here is the info for USDA Zone 8b.

Average Date of Last Frost (spring)March 15
Average Date of First Frost (fall)November 15
Lowest Expected Low15°F
Highest Expected Low20°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 20°F.

Plants to Grow in Happy Valley

You may be interested in your other planting guides for Happy Valley.