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

The first chance to plant delphinium in Cincinnati should be estimated by referring to 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 do well in a tiny bit of cold which means that you can plant them just a tiny bit earlier in the year than other frost tender plants.

The earliest that you can plant delphinium in Cincinnati 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. You probably don't want to wait any later than that or else your delphinium may not have a chance to grow to maturity. If you are starting your delphinium indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

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

Always keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for Cincinnati and it can change quite a bit from year to year. Half of the time in Cincinnati you get surprised by a frost after April 15 so be sure to be ready to protect your delphinium in the event of one of those late frosts.

USDA Zone Info for Cincinnati

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 Cincinnati

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