Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By looking at the USDA zone info for Helena you should be able to estimate when to plant dusty miller.

Planting Calendar for Dusty Miller

Frost tolerance for dusty miller:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Dusty Miller are very cold tolerant which means that you can get them planted much earlier than other plants that might not handle the cold.

The earliest that you can plant dusty miller 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 dusty miller and expect a good harvest is probably August. If you wait any later than that and your dusty miller may not have a chance to fully mature. Starting your dusty miller indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on May 15 in Helena. It might get as low as -25°F during the coldest months of winter.

Remember that USDA zone info for Helena may not be accurate from year to year and the actual date of last frost changes from year to year. Half of the time in Helena it frosts late in the year after May 15 so make sure that you are ready to protect your dusty miller if you have 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.