One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

A common way of figuring out when to plant scutellaria is to look at the USDA zone info for Helena.

Planting Calendar for Scutellaria

Frost tolerance for scutellaria:	Not tolerant of frost.
When to plant:	After the last frost has passed.

Scutellaria require warm weather which tells us that you have to wait until it warms up after the last frost has passed before you can plant them.

The earliest that you can plant scutellaria in Helena 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 scutellaria and expect a good harvest is probably August. If you wait any later than that and your scutellaria may not have a chance to grow to maturity. Starting your scutellaria indoors is a great way to get them started a little bit earlier.

Last Frost Date

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

Just be sure to remember that USDA zone info for Helena is not always accurate and the actual date of last frost can change quite a bit from year to year. Half of the time in Helena you get a frost after May 15 so make sure that you are ready to cover your scutellaria in the event of 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.