The USDA Zone info is a great tool for gardeners to help us estimate your gardening 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 impatiens in Lewiston should be estimated by reviewing the USDA zone info.

Planting Calendar for Impatiens

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

It's probably a bad idea to plant impatiens until after the last frost because they do not do well in cold weather.

The earliest that you can plant impatiens 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 impatiens and expect a good harvest is probably August. If you wait any later than that and your impatiens may not have a chance to fully mature. If you are starting your impatiens indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

On average the last frost is on April 15 in Lewiston. In the coldest months of winter you can expect an average low temperature of 5°F.

It's important to remember that the actual date of last frost is just an average because it is based on the USDA zone info for Lewiston and it can change quite a bit from year to year. Since half of the time in Lewiston you get surprised by a frost after April 15 be ready to protect your impatiens in the event of one of those late frosts.

USDA Zone Info for Lewiston

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 Lewiston

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