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 you can plant thyme in Portland by using the USDA zone info.

Planting Calendar for Thyme

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

Since thyme are one of those plants that can tolerate quite a bit of cold weather you can plant them quite a bit earlier in the year than other frost tender plants.

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

Last Frost Date

On average the last frost is on April 15 in Portland. In the coldest months of winter you should expect an average low temperature of -15°F.

Keep in mind that USDA zone info for Portland may not be accurate from year to year and the actual date of last frost is different every year. Since half of the time in Portland last frost occurs after April 15 be ready to protect your thyme in the event of a late frost.

USDA Zone Info for Portland

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-15°F
Highest Expected Low	-10°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 -10°F.

Plants to Grow in Portland

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