The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By reviewing the USDA zone info for Lone Tree you should be able to figure out when it's a good idea to plant purple coneflower.

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 do ok in moderate cold you can plant them slightly earlier in the year than more sensitive plants.

The earliest that you can plant purple coneflower in Lone Tree 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. 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 couple of weeks earlier.

Last Frost Date

In Lone Tree the average date of last frost happens on April 15. In the coldest months of winter you can expect an average low temperature of -15°F.

Since the USDA zone info for Lone Tree is not always accurate the actual date of last frost is different every year. Half of the time in Lone Tree you get surprised by a frost after April 15 so always be ready to protect your purple coneflower in the event of one of those late frosts.

USDA Zone Info for Lone Tree

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 Lone Tree

You may be interested in your other planting guides for Lone Tree.