One of the first steps you take when you are estimating your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You should be able to figure out when you can plant violas by looking at the USDA zone info for Billings.

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 one of those plants that can tolerate quite a bit of cold weather you can plant them quite a bit earlier in the year than more sensitive plants.

The earliest that you can plant violas in Billings 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. You probably don't want to wait any later than that or else your violas may not have a chance to grow to maturity. Starting your violas indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average the last frost is on May 15 in Billings. It might get as low as -25°F during the coldest months of winter.

Since the USDA zone info for Billings is an average the actual date of last frost changes from year to year. Since half of the time in Billings last frost occurs after May 15 be ready to protect your violas in the event of one of those late frosts.

USDA Zone Info for Billings

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Billings

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