One of the first steps you take when you are determining your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You can figure out when you can plant rosemary in Walla Walla by reviewing the USDA zone info.

Planting Calendar for Rosemary

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

You can plant rosemary much earlier in the year because they do well in cold.

The earliest that you can plant rosemary in Walla Walla 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 rosemary and expect a good harvest is probably September. Any later than that and your rosemary may not have a chance to fully mature. You can get started a few weeks earlier by starting your rosemary indoors.

Last Frost Date

The average date of last frost is April 15 in Walla Walla. In the coldest months of winter you should expect an average low temperature of 0°F.

Since the USDA zone info for Walla Walla is not always accurate the actual date of last frost can change quite a bit from year to year. Half of the time in Walla Walla it frosts late in the year after April 15 so always be ready to protect your rosemary if you have a surprise late frost.

USDA Zone Info for Walla Walla

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 Walla Walla

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