The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You can determine when it's a good idea to plant four o' clock in Mercer Island by referring to the USDA zone info.

Planting Calendar for Four O' Clock

Frost tolerance for four o' clock:	Not tolerant of frost.
When to plant:	After the last frost.

Since four o' clock do not do well in cold weather you really should wait until after the last frost when the weather gets warmer before you can plant them.

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

Last Frost Date

On average the last frost when the weather gets warmer is on March 15 in Mercer Island. You can expect an average low temperature of 15°F in the coldest months of winter.

Since the USDA zone info for Mercer Island is not always accurate the actual date of last frost changes from year to year. Since half of the time in Mercer Island last frost occurs after March 15 be ready to cover your four o' clock 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.