Before planting it is a good idea to find your USDA Zone info to determine 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.

The USDA zone info for Sterling Heights should be reviewed to estimate when it's a good idea to plant anchusa.

Planting Calendar for Anchusa

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

Anchusa tend to make it in pretty solid cold which means that you can plant them earlier in the year than more sensitive plants.

The earliest that you can plant anchusa in Sterling Heights 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. Any later than that and your anchusa may not have a chance to really do well. Starting your anchusa indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Sterling Heights. In the coldest months of winter you can expect an average low temperature of -10°F.

Since the USDA zone info for Sterling Heights may not be accurate from year to year the actual date of last frost can change quite a bit from year to year. Since half of the time in Sterling Heights last frost occurs after April 15 be ready to cover your anchusa in the event of a surprise late frost.

USDA Zone Info for Sterling Heights

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Sterling Heights

You may be interested in your other planting guides for Sterling Heights.