When to Plant Onions in Manhattan, KS

The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Manhattan you can figure out when you can plant onions by reviewing the USDA zone info.


Planting Calendar for Onions

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

Since onions are very cold tolerant you can plant them a lot earlier in the year than more sensitive plants.

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 Manhattan 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 fully mature. You can get started a couple of weeks earlier by starting your onions indoors.

Last Frost Date

The average date of last frost is April 15 in Manhattan. In the coldest months of winter you can expect an average low temperature of -10°F.

Since the USDA zone info for Manhattan is an average the actual date of last frost is different every year. Since half of the time in Manhattan last frost occurs after April 15 be ready to cover your onions if you have one of those late frosts.

USDA Zone Info for Manhattan

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 Manhattan

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