One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By referring to the USDA zone info for Happy Valley it's possible to figure out when to plant lisianthus.

Planting Calendar for Lisianthus

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

Since lisianthus require warm weather it is necessary to wait until after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant lisianthus in Happy Valley 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 grow to maturity. Starting your lisianthus indoors is a great way to get them started a little bit earlier.

Last Frost Date

The average date of last frost is March 15 in Happy Valley. You should expect an average low temperature of 15°F in the coldest months of winter.

Since the USDA zone info for Happy Valley is an average the actual date of last frost is different every year. Since half of the time in Happy Valley it frosts late in the year after March 15 be ready to cover your lisianthus in the event of a surprise late frost.

USDA Zone Info for Happy Valley

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 Happy Valley

You may be interested in your other planting guides for Happy Valley.