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

A common way of determining when it's a good idea to plant delphinium is to refer to the USDA zone info for Culpeper.

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 barely cold tolerant which tells us that you can plant them slightly earlier than other plants that might not handle the cold.

The earliest that you can plant delphinium in Culpeper 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 grow to maturity. 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

On average all chance of frost has passed is on April 15 in Culpeper. It might get as low as 0°F during the coldest months of winter.

Just be sure to remember that the actual date of last frost is an average because it is based on the USDA zone info for Culpeper and it is different every year. Half of the time in Culpeper it frosts late in the year after April 15 so be sure to be ready to protect your delphinium if you have a surprise late frost.

USDA Zone Info for Culpeper

Here is the info for USDA Zone 7a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	0°F
Highest Expected Low	5°F

This means that on a really cold year, the coldest it will get is 0°F. On most years you should be prepared to experience lows near 5°F.

Plants to Grow in Culpeper

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