When to Plant Zinnia in Keokuk, IA

The USDA Zone info is a great tool for gardeners to help us determine 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.

It's possible to figure out when it's a good idea to plant zinnia by reviewing the USDA zone info for Keokuk.


Planting Calendar for Zinnia

Frost tolerance for zinnia: Not tolerant of frost.
When to plant: After the last frost has passed.

Zinnia do not do well in cold weather which means that you must wait until it warms up after the last frost has passed before you can plant them.

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

The earliest that you can plant zinnia in Keokuk is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant zinnia and expect a good harvest is probably August. If you wait any later than that and your zinnia may not have a chance to really do well. You can get started a few weeks earlier by starting your zinnia indoors.

Last Frost Date

On average the last frost is on April 15 in Keokuk. You can expect an average low temperature of -10°F in the coldest months of winter.

Since the USDA zone info for Keokuk is not always accurate the actual date of last frost will vary from year to year. Since half of the time in Keokuk last frost occurs after April 15 be ready to protect your zinnia if you have one of those late frosts.

USDA Zone Info for Keokuk

Here is the info for USDA Zone 6a.

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

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

Plants to Grow in Keokuk

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