One of the best tools that you have as gardeners to help us determine 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.

A common way of making a decision about when you can plant salvia is to refer to the USDA zone info for Billings.

Planting Calendar for Salvia

Frost tolerance for salvia:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Since salvia are one of those plants that can tolerate a tiny bit of cold weather you can plant them a bit earlier in the year than other frost tender plants.

The earliest that you can plant salvia in Billings 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 salvia and expect a good harvest is probably August. You probably don't want to wait any later than that or else your salvia may not have a chance to fully mature. If you are starting your salvia indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

On average all chance of frost has passed is on May 15 in Billings. You can expect an average low temperature of -25°F in the coldest months of winter.

Always keep in mind that USDA zone info for Billings is an average and the actual date of last frost can change quite a bit from year to year. Half of the time in Billings it frosts late in the year after May 15 so make sure that you are ready to protect your salvia if you have 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.