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.

In Mercer Island you can estimate when it's possible to plant torenia by checking out the USDA zone info.

Planting Calendar for Torenia

Frost tolerance for torenia:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

Since torenia do not do well in cold weather it is important to wait until after the last frost when the weather gets warmer before you can plant them.

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

Last Frost Date

The average date of last frost is 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. Half of the time in Mercer Island you get surprised by a frost after March 15 so be sure to be ready to cover your torenia 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.