One of the first steps you take when you are figuring out your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The earliest that you can plant purple coneflower in Umatilla should be determined by looking at the USDA zone info.

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 just a tiny bit earlier in the year because they are barely cold tolerant.

The earliest that you can plant purple coneflower in Umatilla 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. You probably don't want to wait any later than that or else your purple coneflower may not have a chance to fully mature. You can get started a few weeks earlier by starting your purple coneflower indoors.

Last Frost Date

In Umatilla the average date of last frost happens on April 15. In the coldest months of winter you should expect an average low temperature of 5°F.

Remember that USDA zone info for Umatilla may not be accurate from year to year and the actual date of last frost is different every year. Since half of the time in Umatilla last frost occurs after April 15 be ready to protect your purple coneflower in the event of a late frost.

USDA Zone Info for Umatilla

Here is the info for USDA Zone 7b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	5°F
Highest Expected Low	10°F

This means that on a really cold year, the coldest it will get is 5°F. On most years you should be prepared to experience lows near 10°F.

Plants to Grow in Umatilla

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