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.

The earliest that you can plant delphinium in Ann Arbor can be figured out by checking out the USDA zone info.

Planting Calendar for Delphinium

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

Delphinium are one of those plants that can tolerate a tiny bit of cold weather which means that you can get them planted just a bit earlier than other plants that might not handle the cold.

The earliest that you can plant delphinium in Ann Arbor 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 delphinium and expect a good harvest is probably August. Any later than that and your delphinium may not have a chance to really do well. You can get started a few weeks earlier by starting your delphinium indoors.

Last Frost Date

In Ann Arbor the average date of last frost happens on April 15. You should expect an average low temperature of -10°F in the coldest months of winter.

Since the USDA zone info for Ann Arbor may not be accurate from year to year the actual date of last frost changes from year to year. Half of the time in Ann Arbor last frost occurs after April 15 so always be ready to protect your delphinium if you have a surprise late frost.

USDA Zone Info for Ann Arbor

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 Ann Arbor

You may be interested in your other planting guides for Ann Arbor.