The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The best time to plant salpiglossis in Billings should be determined by looking at the USDA zone info.

Planting Calendar for Salpiglossis

Frost tolerance for salpiglossis:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

Since salpiglossis do not do well in cold weather you have to wait until after the last frost has passed before you can plant them.

The earliest that you can plant salpiglossis 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 salpiglossis and expect a good harvest is probably August. Any later than that and your salpiglossis may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your salpiglossis indoors.

Last Frost Date

In Billings the average date of last frost happens on May 15. In the coldest months of winter you should expect an average low temperature of -25°F.

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 can change quite a bit from year to year. Since half of the time in Billings you get surprised by a frost after May 15 be ready to cover your salpiglossis in the event of a surprise 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.