When to Plant Onions in Kansas City, MO

One of the first steps you take when you are making a decision about 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 USDA zone info for Kansas City should be looked at to estimate when it's the best time to plant onions.


Planting Calendar for Onions

Frost tolerance for onions: Very tolerant of frost.
When to plant: Up to 7 weeks before last frost.

Onions can survive in a bit of cold which means that you can plant them earlier in the year than plants that are more sensitive to the cold.

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

The earliest that you can plant onions in Kansas City 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 onions and expect a good harvest is probably September. Any later than that and your onions may not have a chance to grow to maturity. Starting your onions indoors is a great way to get them started a little bit earlier.

Last Frost Date

On average the last frost has passed is on April 15 in Kansas City. In the coldest months of winter you can expect an average low temperature of -5°F.

Remember that USDA zone info for Kansas City is not always accurate and the actual date of last frost can change quite a bit from year to year. Half of the time in Kansas City last frost occurs after April 15 so make sure that you are ready to cover your onions in the event of one of those late frosts.

USDA Zone Info for Kansas City

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)April 15
Average Date of First Frost (fall)October 15
Lowest Expected Low-5°F
Highest Expected Low0°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 0°F.

Plants to Grow in Kansas City

You may be interested in your other planting guides for Kansas City.