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.

In Cleveland you can figure out when it's the best time to plant delphinium 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.

You can plant delphinium slightly earlier in the year because they do ok in moderate cold.

The earliest that you can plant delphinium in Cleveland 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 delphinium and expect a good harvest is probably September. Any later than that and your delphinium may not have a chance to fully mature. If you are starting your delphinium indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

In Cleveland the average date of last frost happens on February 15. You can expect an average low temperature of 20°F in the coldest months of winter.

Since the USDA zone info for Cleveland is an average the actual date of last frost can change quite a bit from year to year. Half of the time in Cleveland it frosts late in the year after February 15 so always be ready to cover your delphinium in the event of one of those late frosts.

USDA Zone Info for Cleveland

Here is the info for USDA Zone 9a.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	20°F
Highest Expected Low	25°F

This means that on a really cold year, the coldest it will get is 20°F. On most years you should be prepared to experience lows near 25°F.

Plants to Grow in Cleveland

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