Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

One way of getting a good idea when you can plant cardinal flower is to check out the USDA zone info for Louisville.

Planting Calendar for Cardinal Flower

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

Since cardinal flower are not cold tolerant it's necessary to wait until after the last frost before you can plant them.

The earliest that you can plant cardinal flower in Louisville is April. However, you really should wait until May 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. If you wait any later than that and your cardinal flower may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your cardinal flower indoors.

Last Frost Date

The average date of last frost is April 15 in Louisville. In the coldest months of winter you should expect an average low temperature of 0°F.

Since the USDA zone info for Louisville is just an average the actual date of last frost is different every year. Half of the time in Louisville last frost occurs after April 15 so be sure to be ready to cover your cardinal flower if you have a late frost.

USDA Zone Info for Louisville

Here is the info for USDA Zone 7a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	0°F
Highest Expected Low	5°F

This means that on a really cold year, the coldest it will get is 0°F. On most years you should be prepared to experience lows near 5°F.

Plants to Grow in Louisville

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