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

It's a good idea to estimate when to plant rosemary by looking at the USDA zone info for Ypsilanti.

Planting Calendar for Rosemary

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

Rosemary tend to make it in a bit of cold which means that you can plant them a lot earlier in the year than other frost tender plants.

The earliest that you can plant rosemary in Ypsilanti 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 rosemary and expect a good harvest is probably September. Any later than that and your rosemary may not have a chance to fully mature. Starting your rosemary indoors is a great way to get them started a few weeks earlier.

Last Frost Date

In Ypsilanti the average date of last frost happens on April 15. In the coldest months of winter you can expect an average low temperature of -10°F.

Remember that the actual date of last frost is just an average because it is based on the USDA zone info for Ypsilanti and it will vary from year to year. Half of the time in Ypsilanti you get surprised by a frost after April 15 so always be ready to cover your rosemary if you have a surprise late frost.

USDA Zone Info for Ypsilanti

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 Ypsilanti

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