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

In Seattle you can determine when it's possible to plant primula by checking out 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 do well in a bit of cold which tells us that you can plant them much earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant primula in Seattle 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. 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 few weeks earlier.

Last Frost Date

The average date of last frost is March 15 in Seattle. You can expect an average low temperature of 15°F in the coldest months of winter.

Remember that USDA zone info for Seattle is an average and the actual date of last frost will vary from year to year. Half of the time in Seattle there is a last frost after March 15 so be sure to be ready to protect your primula in the event of a surprise late frost.

USDA Zone Info for Seattle

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 Seattle

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