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When to Plant Cardinal Flower in Harvard, IL

One of the best tools that you have as gardeners to help us determine 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.

The USDA zone info for Harvard can be used to determine when it's possible to plant cardinal flower.


Planting Calendar for Cardinal Flower

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

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

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant cardinal flower
Possibly ok, but a risky time to plant cardinal flower
Probably not a good time to plant cardinal flower

The earliest that you can plant cardinal flower in Harvard 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 really do well. If you are starting your cardinal flower indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

On average the last frost is on April 15 in Harvard. You should expect an average low temperature of -15°F in the coldest months of winter.

It's important to remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Harvard and it is different every year. Half of the time in Harvard last frost occurs after April 15 so make sure that you are prepared to protect your cardinal flower if you have a surprise late frost.

USDA Zone Info for Harvard

Here is the info for USDA Zone 5b.

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

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Harvard

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