One of the first steps you take when you are making a decision about your gardening schedule is find your 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.

In Colville you can estimate when you can plant primula by using 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 ok in a bit of cold which tells us that you can plant them much earlier in the year than more sensitive plants.

The earliest that you can plant primula in Colville 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 fully mature. You can get started a couple of weeks earlier by starting your primula indoors.

Last Frost Date

The average date of last frost is April 15 in Colville. In the coldest months of winter you can expect an average low temperature of -10°F.

Always keep in mind that USDA zone info for Colville is an average and the actual date of last frost is different every year. Half of the time in Colville it frosts late in the year after April 15 so be sure to be ready to cover your primula in the event of a late frost.

USDA Zone Info for Colville

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Colville

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