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.

The first chance to plant primroses in Corvallis should be determined by referring to the USDA zone info.

Planting Calendar for Primroses

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

Primroses are very cold tolerant which means that you can get them planted much earlier than plants that are more sensitive to the cold.

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

Last Frost Date

On average the last frost has passed is on March 15 in Corvallis. It might get as low as 15°F during the coldest months of winter.

Remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Corvallis and it will vary from year to year. Half of the time in Corvallis last frost occurs after March 15 so make sure that you are prepared to protect your primroses in the event of a surprise late frost.

USDA Zone Info for Corvallis

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 Corvallis

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