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When to Plant Purple Coneflower in Ottumwa, IA

Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. 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 Ottumwa 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 slightly earlier in the year because they are one of those plants that can tolerate a tiny bit of cold weather.

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 Ottumwa 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. You can get started a couple of weeks earlier by starting your purple coneflower indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Ottumwa. It might get as low as -15°F during the coldest months of winter.

Always keep in mind that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Ottumwa and it will vary from year to year. Half of the time in Ottumwa 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 Ottumwa

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 Ottumwa

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