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.

You can estimate when to plant anchusa in Detroit by referring to the USDA zone info.

Planting Calendar for Anchusa

Frost tolerance for anchusa:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Anchusa are very cold tolerant which tells us that you can start planting them much earlier than more sensitive plants.

The earliest that you can plant anchusa in Detroit is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant anchusa and expect a good harvest is probably September. If you wait any later than that and your anchusa may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your anchusa indoors.

Last Frost Date

In Detroit the average date of last frost happens on April 15. You should expect an average low temperature of -5°F in the coldest months of winter.

It's important to remember that the actual date of last frost is just an average because it is based on the USDA zone info for Detroit and it can change quite a bit from year to year. Half of the time in Detroit there is a last frost after April 15 so be sure to be ready to cover your anchusa if you have a late frost.

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.