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.

The first chance to plant delphinium in Harrison should be estimated 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.

Since delphinium are one of those plants that can tolerate a tiny bit of cold weather you can plant them a bit earlier in the year than more sensitive plants.

The earliest that you can plant delphinium in Harrison 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 really do well. If you are starting your delphinium indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Harrison. It might get as low as -10°F during the coldest months of winter.

Since the USDA zone info for Harrison is just an average the actual date of last frost is different every year. Half of the time in Harrison you get a frost after April 15 so make sure that you are ready to protect your delphinium if you have one of those late frosts.

USDA Zone Info for Harrison

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 Harrison

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