Before planting it is a good idea to find your USDA Zone info to estimate 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 Boulder you can estimate when it's the best time to plant dusty miller by referring to the USDA zone info.

Planting Calendar for Dusty Miller

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

You can plant dusty miller quite a bit earlier in the year because they do well in cold.

The earliest that you can plant dusty miller in Boulder is February. However, you really should wait until March 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 September. You probably don't want to wait any later than that or else your dusty miller may not have a chance to fully mature. If you are starting your dusty miller indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Boulder. In the coldest months of winter you can expect an average low temperature of -15°F.

Since the USDA zone info for Boulder is just an average the actual date of last frost changes from year to year. Since half of the time in Boulder you get a frost after April 15 be ready to protect your dusty miller in the event of one of those late frosts.

USDA Zone Info for Boulder

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-15°F
Highest Expected Low	-10°F

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Boulder

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