The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

You can estimate when it's possible to plant primroses in Hermiston by looking at 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 cold which means that you can get them planted much earlier than more sensitive plants.

The earliest that you can plant primroses in Hermiston 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 grow to maturity. Starting your primroses indoors is a great way to get them started a little bit earlier.

Last Frost Date

In Hermiston the average date of last frost happens on April 15. You can expect an average low temperature of 0°F in the coldest months of winter.

Since the USDA zone info for Hermiston is just an average the actual date of last frost is different every year. Since half of the time in Hermiston you get a frost after April 15 be ready to protect your primroses if you have a surprise late frost.

USDA Zone Info for Hermiston

Here is the info for USDA Zone 7a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	0°F
Highest Expected Low	5°F

This means that on a really cold year, the coldest it will get is 0°F. On most years you should be prepared to experience lows near 5°F.

Plants to Grow in Hermiston

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