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 USDA zone info for Great Falls can be used to determine when you can plant violas.

Planting Calendar for Violas

Frost tolerance for violas:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Since violas are very cold tolerant you can plant them quite a bit earlier in the year than other plants that might not handle the cold.

The earliest that you can plant violas in Great Falls is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant violas and expect a good harvest is probably August. If you wait any later than that and your violas may not have a chance to really do well. You can get started a little bit earlier by starting your violas indoors.

Last Frost Date

The average date of last frost is May 15 in Great Falls. It might get as low as -30°F during the coldest months of winter.

Since the USDA zone info for Great Falls may not be accurate from year to year the actual date of last frost will vary from year to year. Half of the time in Great Falls it frosts late in the year after May 15 so make sure that you are ready to cover your violas if you have a surprise late frost.

USDA Zone Info for Great Falls

Here is the info for USDA Zone 4a.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-30°F
Highest Expected Low	-25°F

This means that on a really cold year, the coldest it will get is -30°F. On most years you should be prepared to experience lows near -25°F.

Plants to Grow in Great Falls

You may be interested in your other planting guides for Great Falls.