One of the first steps you take when you are getting a good idea your gardening schedule is find your 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.

In Lewiston you can estimate when it's the best time to plant calliopsis by checking out the USDA zone info.

Planting Calendar for Calliopsis

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

It's probably not a good idea to plant calliopsis until after all chance of frost has passed because they require warm weather.

The earliest that you can plant calliopsis in Lewiston 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 calliopsis and expect a good harvest is probably August. You probably don't want to wait any later than that or else your calliopsis may not have a chance to really do well. If you are starting your calliopsis indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

The average date of last frost is April 15 in Lewiston. In the coldest months of winter you can expect an average low temperature of -15°F.

It's important to remember that USDA zone info for Lewiston is an average and the actual date of last frost is different every year. Since half of the time in Lewiston it frosts late in the year after April 15 be ready to protect your calliopsis in the event of one of those late frosts.

USDA Zone Info for Lewiston

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 Lewiston

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