One of the first steps you take when you are getting a good idea your gardening schedule is find your 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.

By using the USDA zone info for Billings it's possible to estimate when it's possible to plant rudbeckia.

Planting Calendar for Rudbeckia

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

You can plant rudbeckia 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 rudbeckia in Billings 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 rudbeckia and expect a good harvest is probably August. Any later than that and your rudbeckia may not have a chance to really do well. If you are starting your rudbeckia indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

In Billings the average date of last frost happens on May 15. In the coldest months of winter you can expect an average low temperature of -25°F.

Since the USDA zone info for Billings is an average the actual date of last frost is different every year. Half of the time in Billings you get surprised by a frost after May 15 so make sure that you are ready to cover your rudbeckia if you have one of those late frosts.

USDA Zone Info for Billings

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 Billings

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