One of the first steps you take when you are making a decision about 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.

In Mercer Island you can determine when to plant potatos by checking out the USDA zone info.

Planting Calendar for Potatos

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

Potatos do well in quite a bit of cold which means that you can plant them a lot earlier in the year than other plants that might not handle the cold.

The earliest that you can plant potatos 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 potatos and expect a good harvest is probably September. If you wait any later than that and your potatos may not have a chance to grow to maturity. Starting your potatos indoors is a great way to get them started a few weeks earlier.

Last Frost Date

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

It's important to remember that USDA zone info for Mercer Island may not be accurate from year to year and the actual date of last frost will vary from year to year. Since half of the time in Mercer Island last frost occurs after March 15 be ready to cover your potatos if you have a surprise late frost.

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.