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.

In South Holland you can determine when it's the best time to plant cardinal flower by referring to 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.

Since cardinal flower require warm weather it is important to wait until after the last frost before you can plant them.

The earliest that you can plant cardinal flower in South Holland 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. Any later than that and your cardinal flower may not have a chance to fully mature. If you are starting your cardinal flower indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

The average date of last frost is April 15 in South Holland. You can expect an average low temperature of -10°F in the coldest months of winter.

Always keep in mind that USDA zone info for South Holland is just an average and the actual date of last frost changes from year to year. Half of the time in South Holland it frosts late in the year after April 15 so just be sure to be ready to cover your cardinal flower if you have a late frost.

USDA Zone Info for South Holland

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 South Holland

You may be interested in your other planting guides for South Holland.