The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The first opportunity to plant primula in Beaverton should be determined by referring to 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.

Primula are very cold tolerant which tells us that you can get them planted much earlier than more sensitive plants.

The earliest that you can plant primula in Beaverton 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 couple of weeks earlier.

Last Frost Date

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

Remember that the actual date of last frost is just an average because it is based on the USDA zone info for Beaverton and it will vary from year to year. Half of the time in Beaverton last frost occurs after March 15 so just be sure to be ready to protect your primula if you have a late frost.

USDA Zone Info for Beaverton

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 Low	15°F
Highest Expected Low	20°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 Beaverton

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