Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

A common way of determining when it's a good idea to plant onions is to use the USDA zone info for Plattsmouth.

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 one of those plants that can tolerate quite a bit of cold weather you can plant them earlier in the year than more sensitive plants.

The earliest that you can plant onions in Plattsmouth 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. You can get started a couple of weeks earlier by starting your onions indoors.

Last Frost Date

In Plattsmouth the average date of last frost happens on April 15. In the coldest months of winter you can expect an average low temperature of -15°F.

Just be sure to remember that USDA zone info for Plattsmouth is not always accurate and the actual date of last frost can change quite a bit from year to year. Since half of the time in Plattsmouth it frosts late in the year after April 15 be ready to protect your onions if you have a late frost.

USDA Zone Info for Plattsmouth

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-15°F
Highest Expected Low	-10°F

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Plattsmouth

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