frostdate name logo in white
frostdate name logo in white

When to Plant Purple Coneflower in Castle Rock, CO

One of the best tools that you have as gardeners to help us estimate 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 earliest that you can plant purple coneflower in Castle Rock should be estimated by checking out the USDA zone info.

Create beautiful hand-made plants at forever-plants.com

Planting Calendar for Purple Coneflower

Frost tolerance for purple coneflower: Tolerant of a very small amount of frost.
When to plant: Up to 3 weeks before last frost.

Since purple coneflower are one of those plants that can tolerate a tiny bit of cold weather you can plant them a bit earlier in the year than plants that are more sensitive to the cold.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant purple coneflower
Possibly ok, but a risky time to plant purple coneflower
Probably not a good time to plant purple coneflower

The earliest that you can plant purple coneflower in Castle Rock is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant purple coneflower and expect a good harvest is probably August. If you wait any later than that and your purple coneflower may not have a chance to fully mature. If you are starting your purple coneflower indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

In Castle Rock the average date of last frost happens on April 15. It might get as low as -15°F during the coldest months of winter.

Keep in mind that USDA zone info for Castle Rock is just an average and the actual date of last frost is different every year. Since half of the time in Castle Rock last frost occurs after April 15 be ready to protect your purple coneflower if you have one of those late frosts.

USDA Zone Info for Castle Rock

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 Castle Rock

You may be interested in your other planting guides for Castle Rock.