One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The first chance to plant cardinal flower in River Forest should be determined by reviewing the USDA zone info.

Planting Calendar for Cardinal Flower

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

Cardinal Flower require warm weather which means that you need to wait until it warms up after the last frost before you can plant them.

The earliest that you can plant cardinal flower in River Forest 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. You probably don't want to wait any later than that or else your cardinal flower may not have a chance to fully mature. Starting your cardinal flower indoors is a great way to get them started a little bit earlier.

Last Frost Date

On average all chance of frost has passed is on April 15 in River Forest. It might get as low as -10°F during the coldest months of winter.

Keep in mind that USDA zone info for River Forest is just an average and the actual date of last frost will vary from year to year. Half of the time in River Forest you get surprised by a frost after April 15 so make sure that you are prepared to cover your cardinal flower in the event of a surprise late frost.

USDA Zone Info for River Forest

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in River Forest

You may be interested in your other planting guides for River Forest.