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

A common way of getting a good idea when it's the best time to plant purple coneflower is to use the USDA zone info for Del Rio.

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.

You can plant purple coneflower slightly earlier in the year because they are barely cold tolerant.

The earliest that you can plant purple coneflower in Del Rio is February. However, you really should wait until March 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 September. Any later than that and your purple coneflower may not have a chance to grow to maturity. You can get started a little bit earlier by starting your purple coneflower indoors.

Last Frost Date

In Del Rio the average date of last frost happens on February 15. In the coldest months of winter you can expect an average low temperature of 20°F.

Since the USDA zone info for Del Rio is just an average the actual date of last frost is different every year. Since half of the time in Del Rio you get a frost after February 15 be ready to protect your purple coneflower in the event of one of those late frosts.

USDA Zone Info for Del Rio

Here is the info for USDA Zone 9a.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	20°F
Highest Expected Low	25°F

This means that on a really cold year, the coldest it will get is 20°F. On most years you should be prepared to experience lows near 25°F.

Plants to Grow in Del Rio

You may be interested in your other planting guides for Del Rio.