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.

In Helena you can figure out when it's possible to plant scabiosa by looking at the USDA zone info.

Planting Calendar for Scabiosa

Frost tolerance for scabiosa:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

You can plant scabiosa a little bit earlier in the year because they are one of those plants that can tolerate a little bit of cold weather.

The earliest that you can plant scabiosa in Helena is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant scabiosa and expect a good harvest is probably August. If you wait any later than that and your scabiosa may not have a chance to really do well. Starting your scabiosa indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

In Helena the average date of last frost happens on May 15. 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 is just an average because it is based on the USDA zone info for Helena and it changes from year to year. Since half of the time in Helena it frosts late in the year after May 15 be ready to protect your scabiosa in the event of a late frost.

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.