One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The USDA zone info for Mukwonago can be read to estimate when it's possible to plant welsh onion.

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 moderate cold which tells us that you can start planting them slightly earlier than plants that are more sensitive to the cold.

The earliest that you can plant welsh onion in Mukwonago 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. 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

In Mukwonago the average date of last frost happens on April 15. It might get as low as -20°F during the coldest months of winter.

Always keep in mind that USDA zone info for Mukwonago is just an average and the actual date of last frost will vary from year to year. Half of the time in Mukwonago there is a last frost after April 15 so make sure that you are prepared to cover your welsh onion if you have a surprise late frost.

USDA Zone Info for Mukwonago

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 Mukwonago

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