Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

You can determine when it's a good idea to plant delphinium in Harrington Park by looking at 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 do well in mild 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 Harrington Park 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. You probably don't want to wait any later than that or else your delphinium may not have a chance to grow to maturity. Starting your delphinium indoors is a great way to get them started a little bit earlier.

Last Frost Date

The average date of last frost is April 15 in Harrington Park. It might get as low as 0°F during the coldest months of winter.

It's important to remember that USDA zone info for Harrington Park is an average and the actual date of last frost is different every year. Half of the time in Harrington Park you get a frost after April 15 so always be ready to protect your delphinium in the event of a late frost.

USDA Zone Info for Harrington Park

Here is the info for USDA Zone 7a.

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

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

Plants to Grow in Harrington Park

You may be interested in your other planting guides for Harrington Park.