Before planting it is a good idea to find your USDA Zone info to determine 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.

By looking at the USDA zone info for Duluth it's possible to estimate when it's the best time 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 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 Duluth 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. You can get started a few weeks earlier by starting your rudbeckia indoors.

Last Frost Date

The average date of last frost is May 15 in Duluth. In the coldest months of winter you can expect an average low temperature of -30°F.

Always keep in mind that the actual date of last frost is not always accurate because it is based on the USDA zone info for Duluth and it will vary from year to year. Half of the time in Duluth you get a frost after May 15 so make sure that you are prepared to protect your rudbeckia if you have a late frost.

USDA Zone Info for Duluth

Here is the info for USDA Zone 4a.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-30°F
Highest Expected Low	-25°F

This means that on a really cold year, the coldest it will get is -30°F. On most years you should be prepared to experience lows near -25°F.

Plants to Grow in Duluth

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