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

You should be able to estimate when it's possible to plant lisianthus by looking at the USDA zone info for Umatilla.

Planting Calendar for Lisianthus

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

Since lisianthus do not do well in cold weather it is necessary to wait until after the last frost has passed before you can plant them.

The earliest that you can plant lisianthus in Umatilla 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. If you are starting your lisianthus indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Umatilla. It might get as low as 5°F during the coldest months of winter.

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

USDA Zone Info for Umatilla

Here is the info for USDA Zone 7b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	5°F
Highest Expected Low	10°F

This means that on a really cold year, the coldest it will get is 5°F. On most years you should be prepared to experience lows near 10°F.

Plants to Grow in Umatilla

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