Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You will be able to determine when to plant zucchini by referring to the USDA zone info for Mercer Island.

Planting Calendar for Zucchini

Frost tolerance for zucchini:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

It's probably not a good idea to plant zucchini until after the last frost because they require warm weather.

The earliest that you can plant zucchini in Mercer Island is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant zucchini and expect a good harvest is probably August. You probably don't want to wait any later than that or else your zucchini may not have a chance to fully mature. You can get started a few weeks earlier by starting your zucchini indoors.

Last Frost Date

The average date of last frost is March 15 in Mercer Island. It might get as low as 15°F during the coldest months of winter.

Since the USDA zone info for Mercer Island is an average the actual date of last frost will vary from year to year. Half of the time in Mercer Island there is a last frost after March 15 so always be ready to protect your zucchini in the event of a 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.