Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In Helena you can determine when you can plant salvia by using the USDA zone info.

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.

Salvia are one of those plants that can tolerate a tiny bit of cold weather which means that you can plant them slightly earlier than plants that are more sensitive to the cold.

The earliest that you can plant salvia in Helena 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. If you wait any later than that and your salvia may not have a chance to really do well. You can get started a couple of weeks earlier by starting your salvia indoors.

Last Frost Date

The average date of last frost is May 15 in Helena. It might get as low as -25°F during the coldest months of winter.

Keep in mind that USDA zone info for Helena is not always accurate and the actual date of last frost will vary from year to year. Since half of the time in Helena you get a frost after May 15 be ready to cover your salvia if you have one of those late frosts.

USDA Zone Info for Helena

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 Helena

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