The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By reviewing the USDA zone info for Keene it's a good idea to determine when you can 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.

Since delphinium do ok in moderate cold you can plant them a bit earlier in the year than other frost tender plants.

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

Last Frost Date

In Keene the average date of last frost happens on March 15. You should expect an average low temperature of 10°F in the coldest months of winter.

Remember that USDA zone info for Keene is not always accurate and the actual date of last frost can change quite a bit from year to year. Since half of the time in Keene it frosts late in the year after March 15 be ready to cover your delphinium if you have one of those late frosts.

USDA Zone Info for Keene

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 Keene

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