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 earliest that you can plant welsh onion in Vermillion can be estimated by checking out the USDA zone info.

Planting Calendar for Welsh onion

Frost tolerance for welsh onion:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Welsh onion are one of those plants that can tolerate a tiny bit of cold weather which means that you can get them planted just a bit earlier than more sensitive plants.

The earliest that you can plant welsh onion in Vermillion 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 welsh onion and expect a good harvest is probably August. You probably don't want to wait any later than that or else your welsh onion may not have a chance to really do well. You can get started a couple of weeks earlier by starting your welsh onion indoors.

Last Frost Date

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

Always keep in mind that USDA zone info for Vermillion is not always accurate and the actual date of last frost changes from year to year. Half of the time in Vermillion it frosts late in the year after April 15 so make sure that you are ready to cover your welsh onion in the event of a surprise late frost.

USDA Zone Info for Vermillion

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 Vermillion

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