Before planting it is a good idea to find your USDA Zone info to estimate 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.

The best time to plant onions in Marion can 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.

Onions do ok in cold weather which means that you can plant them a lot earlier in the year than other frost tender plants.

The earliest that you can plant onions in Marion 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 fully mature. 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

In Marion the average date of last frost happens on April 15. You should expect an average low temperature of -10°F in the coldest months of winter.

Remember that USDA zone info for Marion is an average and the actual date of last frost changes from year to year. Half of the time in Marion it frosts late in the year after April 15 so always be ready to cover your onions if you have a late frost.

USDA Zone Info for Marion

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 Marion

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