Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In Kelso you can estimate when you can plant rosemary by using 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.

Rosemary tend to make it in cold weather which tells us that you can plant them earlier in the year than more sensitive plants.

The earliest that you can plant rosemary 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 rosemary and expect a good harvest is probably September. Any later than that and your rosemary may not have a chance to fully mature. If you are starting your rosemary 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 Kelso. In the coldest months of winter you can expect an average low temperature of 15°F.

Keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for Kelso and it is different every year. Since half of the time in Kelso it frosts late in the year after March 15 be ready to protect your rosemary if you have 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.