The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Lewiston should be reviewed to figure out when you can plant achimenes.

Planting Calendar for Achimenes

Frost tolerance for achimenes:	Not tolerant of frost.
When to plant:	After the last frost has passed.

Since achimenes are not cold tolerant it is important to wait until after the last frost before you can plant them.

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

Last Frost Date

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

Remember that the actual date of last frost is an average because it is based on the USDA zone info for Lewiston and it changes from year to year. Half of the time in Lewiston last frost occurs after April 15 so make sure that you are ready to cover your achimenes if you have a surprise late frost.

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.