One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A way of getting a good idea when it's the best time to plant delphinium is to consult the USDA zone info for Covington.

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.

Since delphinium are barely cold tolerant you can plant them slightly earlier in the year than other frost tender plants.

The earliest that you can plant delphinium in Covington 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. If you wait 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 little bit earlier.

Last Frost Date

In Covington the average date of last frost happens on February 15. In the coldest months of winter you should expect an average low temperature of 20°F.

Remember that USDA zone info for Covington is an average and the actual date of last frost will vary from year to year. Half of the time in Covington you get surprised by a frost after February 15 so make sure that you are ready to cover your delphinium in the event of one of those late frosts.

USDA Zone Info for Covington

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 Covington

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