The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A common way of estimating when it's the best time to plant welsh onion is to use the USDA zone info for Lombard.

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 tend to make it in some cold which means that you can plant them slightly earlier in the year than other plants that might not handle the cold.

The earliest that you can plant welsh onion in Lombard 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 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 April 15 in Lombard. It might get as low as -15°F during the coldest months of winter.

Always keep in mind that USDA zone info for Lombard is just an average and the actual date of last frost changes from year to year. Half of the time in Lombard it frosts late in the year after April 15 so be sure to be ready to cover your welsh onion if you have one of those late frosts.

USDA Zone Info for Lombard

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-15°F
Highest Expected Low	-10°F

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Lombard

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