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.

The earliest that you can plant lisianthus in Washington can be determined by looking at the USDA zone info.

Planting Calendar for Lisianthus

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

Lisianthus require warm weather which tells us that it is important to wait until it warms up after the last frost has passed before you can plant them.

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

Last Frost Date

In Washington the average date of last frost happens on April 15. It might get as low as -15°F during the coldest months of winter.

Since the USDA zone info for Washington is an average the actual date of last frost will vary from year to year. Since half of the time in Washington you get a frost after April 15 be ready to cover your lisianthus in the event of one of those late frosts.

USDA Zone Info for Washington

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-15°F
Highest Expected Low	-10°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 -10°F.

Plants to Grow in Washington

You may be interested in your other planting guides for Washington.