One of the first steps you take when you are making a decision about your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The USDA zone info for Rockingham can be used to estimate when it's the best time to plant delphinium.

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 can survive in a tiny bit of cold which tells us that you can plant them a bit earlier in the year than other plants that might not handle the cold.

The earliest that you can plant delphinium in Rockingham 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 couple of weeks earlier by starting your delphinium indoors.

Last Frost Date

The average date of last frost is March 15 in Rockingham. In the coldest months of winter you can expect an average low temperature of 10°F.

Since the USDA zone info for Rockingham is just an average the actual date of last frost will vary from year to year. Since half of the time in Rockingham it frosts late in the year after March 15 be ready to cover your delphinium if you have a surprise late frost.

USDA Zone Info for Rockingham

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°F

This means that on a really cold year, the coldest it will get is 10°F. On most years you should be prepared to experience lows near 15°F.

Plants to Grow in Rockingham

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