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.

The first opportunity to plant onions in Sioux Center should be figured out 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 earlier in the year than other frost tender plants.

The earliest that you can plant onions in Sioux Center 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. If you wait any later than that and your onions may not have a chance to fully mature. If you are starting your onions indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

The average date of last frost is April 15 in Sioux Center. You should expect an average low temperature of -20°F in the coldest months of winter.

Since the USDA zone info for Sioux Center may not be accurate from year to year the actual date of last frost can change quite a bit from year to year. Half of the time in Sioux Center last frost occurs after April 15 so be sure to be ready to protect your onions in the event of a late frost.

USDA Zone Info for Sioux Center

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 Sioux Center

You may be interested in your other planting guides for Sioux Center.