One of the first steps you take when you are figuring out your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A way of figuring out when you can plant welsh onion is to check out the USDA zone info for Rhinelander.

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 do ok in mild cold which tells us that you can plant them slightly earlier in the year than more sensitive plants.

The earliest that you can plant welsh onion in Rhinelander is April. However, you really should wait until May 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. If you wait any later than that and your welsh onion may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your welsh onion indoors.

Last Frost Date

On average all chance of frost has passed is on May 15 in Rhinelander. In the coldest months of winter you can expect an average low temperature of -30°F.

Keep in mind that USDA zone info for Rhinelander may not be accurate from year to year and the actual date of last frost will vary from year to year. Half of the time in Rhinelander you get surprised by a frost after May 15 so make sure that you are prepared to protect your welsh onion in the event of a surprise late frost.

USDA Zone Info for Rhinelander

Here is the info for USDA Zone 4a.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-30°F
Highest Expected Low	-25°F

This means that on a really cold year, the coldest it will get is -30°F. On most years you should be prepared to experience lows near -25°F.

Plants to Grow in Rhinelander

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