One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Kelso you can determine when you can plant primroses by checking out 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 do well in a bit of cold which tells us that you can plant them earlier in the year than other frost tender plants.

The earliest that you can plant primroses in Kelso 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. Any later than that and your primroses may not have a chance to really do well. Starting your primroses indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average all chance of frost has passed is on March 15 in Kelso. You should expect an average low temperature of 15°F in the coldest months of winter.

Always keep in mind that the actual date of last frost is just an average because it is based on the USDA zone info for Kelso and it will vary from year to year. Half of the time in Kelso there is a last frost after March 15 so be sure to be ready to protect your primroses in the event of a surprise late frost.

USDA Zone Info for Kelso

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 Kelso

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