Before planting it is a good idea to find your USDA Zone info to determine 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.

The earliest that you can plant oregano in Mercer Island can be figured out by referring to the USDA zone info.

Planting Calendar for Oregano

Frost tolerance for oregano:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

You can plant oregano a little earlier in the year because they are one of those plants that can tolerate a little bit of cold weather.

The earliest that you can plant oregano in Mercer Island 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 oregano and expect a good harvest is probably September. Any later than that and your oregano may not have a chance to really do well. You can get started a little bit earlier by starting your oregano indoors.

Last Frost Date

In Mercer Island the average date of last frost happens on March 15. You can expect an average low temperature of 15°F in the coldest months of winter.

Since the USDA zone info for Mercer Island may not be accurate from year to year the actual date of last frost can change quite a bit from year to year. Half of the time in Mercer Island you get surprised by a frost after March 15 so be sure to be ready to protect your oregano in the event of one of those late frosts.

USDA Zone Info for Mercer Island

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 Mercer Island

You may be interested in your other planting guides for Mercer Island.