When to Plant Onions in Brookings, SD

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

You can figure out when it's the best time to plant onions in Brookings 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.

Onions tend to make it in a bit of cold which means that you can plant them much earlier in the year than other plants that might not handle 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 Brookings 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 onions and expect a good harvest is probably August. Any later than that and your onions may not have a chance to really do well. If you are starting your onions indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on May 15 in Brookings. In the coldest months of winter you should expect an average low temperature of -25°F.

Just be sure to remember that the actual date of last frost is an average because it is based on the USDA zone info for Brookings and it changes from year to year. Since half of the time in Brookings you get a frost after May 15 be ready to cover your onions if you have one of those late frosts.

USDA Zone Info for Brookings

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)May 15
Average Date of First Frost (fall)September 15
Lowest Expected Low-25°F
Highest Expected Low-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Brookings

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