When to Plant Cardinal Flower in Johnstown, CO

The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You should be able to determine when it's a good idea to plant cardinal flower by using the USDA zone info for Johnstown.


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 are not cold tolerant it's important to wait until after the last frost 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 Johnstown 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 grow to maturity. Starting your cardinal flower indoors is a great way to get them started a little bit earlier.

Last Frost Date

On average the last frost has passed is on April 15 in Johnstown. You can expect an average low temperature of -15°F in the coldest months of winter.

Just be sure to remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Johnstown and it changes from year to year. Half of the time in Johnstown you get surprised by a frost after April 15 so always be ready to protect your cardinal flower if you have a late frost.

USDA Zone Info for Johnstown

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 Johnstown

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