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.

A way of figuring out when you can plant delphinium is to use the USDA zone info for Norfolk.

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 a bit earlier in the year because they are barely cold tolerant.

The earliest that you can plant delphinium in Norfolk 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. You can get started a little bit earlier by starting your delphinium indoors.

Last Frost Date

In Norfolk the average date of last frost happens on April 15. It might get as low as -20°F during the coldest months of winter.

Since the USDA zone info for Norfolk may not be accurate from year to year the actual date of last frost changes from year to year. Since half of the time in Norfolk there is a last frost after April 15 be ready to cover your delphinium in the event of a late frost.

USDA Zone Info for Norfolk

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°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 -15°F.

Plants to Grow in Norfolk

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