One of the best tools that you have as gardeners to help us estimate your gardening schedule is the 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.

A common way of making a decision about when you can plant delphinium is to use the USDA zone info for Danville.

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 Danville 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. If you wait any later than that and your delphinium may not have a chance to really do well. 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

On average the last frost is on April 15 in Danville. You can expect an average low temperature of -5°F in the coldest months of winter.

Just be sure to remember that USDA zone info for Danville is just an average and the actual date of last frost can change quite a bit from year to year. Half of the time in Danville last frost occurs after April 15 so make sure that you are prepared to cover your delphinium in the event of a late frost.

USDA Zone Info for Danville

Here is the info for USDA Zone 6b.

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

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

Plants to Grow in Danville

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