Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You can figure out when to plant evolvulus in Billings by looking at the USDA zone info.

Planting Calendar for Evolvulus

Frost tolerance for evolvulus:	Not tolerant of frost.
When to plant:	After the last frost.

It's a bad idea to plant evolvulus until after the last frost has passed because they are not cold tolerant.

The earliest that you can plant evolvulus in Billings is May. However, you really should wait until June if you don't want to take any chances.

The last month that you can plant evolvulus and expect a good harvest is probably August. You probably don't want to wait any later than that or else your evolvulus may not have a chance to grow to maturity. Starting your evolvulus indoors is a great way to get them started a little bit earlier.

Last Frost Date

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

Just be sure to remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Billings and it is different every year. Since half of the time in Billings it frosts late in the year after May 15 be ready to cover your evolvulus in the event of a late frost.

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.