Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In Detroit you can determine when it's possible to plant bells of ireland by looking at the USDA zone info.

Planting Calendar for Bells of Ireland

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

Bells of Ireland do ok in moderate cold which means that you can get them planted just a bit earlier than more sensitive plants.

The earliest that you can plant bells of ireland in Detroit 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 bells of ireland and expect a good harvest is probably August. You probably don't want to wait any later than that or else your bells of ireland may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your bells of ireland indoors.

Last Frost Date

The average date of last frost is April 15 in Detroit. You can expect an average low temperature of -5°F in the coldest months of winter.

It's important to remember that USDA zone info for Detroit is an average and the actual date of last frost can change quite a bit from year to year. Since half of the time in Detroit you get a frost after April 15 be ready to protect your bells of ireland in the event of one of those late frosts.

USDA Zone Info for Detroit

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in Detroit

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