One of the best tools that you have as gardeners to help us figure out your gardening schedule is the 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 reviewing the USDA zone info for Holmen it's possible to determine when you can plant cardinal flower.

Planting Calendar for Cardinal Flower

Frost tolerance for cardinal flower:	Not tolerant of frost.
When to plant:	After the last frost.

You can not plant cardinal flower until after the last frost has passed because they do not do well in cold weather.

The earliest that you can plant cardinal flower in Holmen is May. However, you really should wait until June if you don't want to take any chances.

The last month that you can plant cardinal flower and expect a good harvest is probably August. You probably don't want to wait any later than that or else your cardinal flower may not have a chance to fully mature. You can get started a little bit earlier by starting your cardinal flower indoors.

Last Frost Date

On average the last frost has passed is on May 15 in Holmen. It might get as low as -25°F during the coldest months of winter.

Since the USDA zone info for Holmen may not be accurate from year to year the actual date of last frost will vary from year to year. Half of the time in Holmen it frosts late in the year after May 15 so always be ready to protect your cardinal flower in the event of a surprise late frost.

USDA Zone Info for Holmen

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 Holmen

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