When to Plant Delphinium in Flat Rock, MI

Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

One way of figuring out when it's the best time to plant delphinium is to use the USDA zone info for Flat Rock.


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 do well in very little cold which tells us that you can plant them just a tiny bit earlier in the year than more sensitive plants.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant delphinium
Possibly ok, but a risky time to plant delphinium
Probably not a good time to plant delphinium

The earliest that you can plant delphinium in Flat Rock 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. If you wait any later than that and your delphinium may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your delphinium indoors.

Last Frost Date

The average date of last frost is April 15 in Flat Rock. In the coldest months of winter you can expect an average low temperature of -5°F.

Keep in mind that USDA zone info for Flat Rock is just an average and the actual date of last frost changes from year to year. Since half of the time in Flat Rock there is a last frost after April 15 be ready to protect your delphinium in the event of a surprise late frost.

USDA Zone Info for Flat Rock

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 Low0°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 Flat Rock

You may be interested in your other planting guides for Flat Rock.