One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By using the USDA zone info for Missoula you will be able to determine when it's possible to plant achimenes.

Planting Calendar for Achimenes

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

It's probably not a good idea to plant achimenes until after the last frost has passed because they require warm weather.

The earliest that you can plant achimenes in Missoula 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. If you wait any later than that and 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 all chance of frost has passed is on April 15 in Missoula. You can expect an average low temperature of -15°F in the coldest months of winter.

It's important to remember that USDA zone info for Missoula is just an average and the actual date of last frost will vary from year to year. Since half of the time in Missoula there is a last frost after April 15 be ready to cover your achimenes in the event of a late frost.

USDA Zone Info for Missoula

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 Missoula

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