One of the first steps you take when you are figuring out 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 Grinnell it's a good idea to determine 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 little earlier in the year because they do well in moderate cold.

The earliest that you can plant rudbeckia in Grinnell 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 rudbeckia and expect a good harvest is probably September. 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

On average the last frost is on April 15 in Grinnell. It might get as low as -20°F during the coldest months of winter.

Remember that USDA zone info for Grinnell 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 Grinnell last frost occurs after April 15 so make sure that you are ready to protect your rudbeckia in the event of a late frost.

USDA Zone Info for Grinnell

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Grinnell

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