One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You can estimate when to plant bunching onions in Tomah by using the USDA zone info.

Planting Calendar for Bunching Onions

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

Since bunching onions are barely cold tolerant you can plant them slightly earlier in the year than other frost tender plants.

The earliest that you can plant bunching onions in Tomah 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 bunching onions and expect a good harvest is probably August. You probably don't want to wait any later than that or else your bunching onions may not have a chance to grow to maturity. You can get started a few weeks earlier by starting your bunching onions indoors.

Last Frost Date

In Tomah the average date of last frost happens on May 15. It might get as low as -25°F during the coldest months of winter.

Since the USDA zone info for Tomah is just an average the actual date of last frost will vary from year to year. Since half of the time in Tomah you get surprised by a frost after May 15 be ready to protect your bunching onions in the event of a late frost.

USDA Zone Info for Tomah

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Tomah

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