When to Plant Onions in Boone, IA

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

You will be able to figure out when it's possible to plant onions by reviewing the USDA zone info for Boone.


Planting Calendar for Onions

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

You can plant onions a lot earlier in the year because they are one of those plants that can tolerate quite a bit of cold weather.

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 Boone 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. You probably don't want to wait any later than that or else your onions may not have a chance to grow to maturity. If you are starting your onions indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

On average all chance of frost has passed is on April 15 in Boone. You should expect an average low temperature of -20°F in the coldest months of winter.

It's important to remember that the actual date of last frost is just an average because it is based on the USDA zone info for Boone and it is different every year. Since half of the time in Boone you get a frost after April 15 be ready to cover your onions in the event of a surprise late frost.

USDA Zone Info for Boone

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)April 15
Average Date of First Frost (fall)October 15
Lowest Expected Low-20°F
Highest Expected Low-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Boone

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