One of the first steps you take when you are estimating 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.

In Detroit you can figure out when it's a good idea to plant impatiens by referring to the USDA zone info.

Planting Calendar for Impatiens

Frost tolerance for impatiens:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

It's a bad idea to plant impatiens until after the last frost because they are not cold tolerant.

The earliest that you can plant impatiens in Detroit 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 impatiens and expect a good harvest is probably August. Any later than that and your impatiens may not have a chance to really do well. If you are starting your impatiens indoors then you might be able to get away with starting them a little bit earlier.

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.

Always keep in mind that the actual date of last frost is just an average because it is based on the USDA zone info for Detroit and it changes from year to year. Since half of the time in Detroit last frost occurs after April 15 be ready to cover your impatiens 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.