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.

In Clarks Summit you can estimate when it's a good idea to plant delphinium by checking out the USDA zone info.

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 tend to make it in a tiny bit of cold which tells us that you can plant them slightly earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant delphinium in Clarks Summit 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. Starting your delphinium indoors is a great way to get them started a few weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Clarks Summit. You can expect an average low temperature of -10°F in the coldest months of winter.

Since the USDA zone info for Clarks Summit is not always accurate the actual date of last frost can change quite a bit from year to year. Since half of the time in Clarks Summit it frosts late in the year after April 15 be ready to protect your delphinium in the event of one of those late frosts.

USDA Zone Info for Clarks Summit

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°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 -5°F.

Plants to Grow in Clarks Summit

You may be interested in your other planting guides for Clarks Summit.