One of the first steps you take when you are making a decision about 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.

One way of making a decision about when it's possible to plant tree onions is to look at the USDA zone info for Waupun.

Planting Calendar for Tree onions

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

Tree onions tend to make it in mild cold which means that you can plant them a bit earlier in the year than more sensitive plants.

The earliest that you can plant tree onions in Waupun 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 tree onions and expect a good harvest is probably August. You probably don't want to wait any later than that or else your tree onions may not have a chance to fully mature. If you are starting your tree onions indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Waupun. It might get as low as -20°F during the coldest months of winter.

Just be sure to remember that USDA zone info for Waupun is not always accurate and the actual date of last frost is different every year. Half of the time in Waupun you get a frost after April 15 so make sure that you are prepared to cover your tree onions if you have a surprise late frost.

USDA Zone Info for Waupun

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 Waupun

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