One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A way of making a decision about when to plant delphinium is to consult the USDA zone info for Carpentersville.

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 some cold which means 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 Carpentersville 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. You can get started a few weeks earlier by starting your delphinium indoors.

Last Frost Date

In Carpentersville the average date of last frost happens on April 15. In the coldest months of winter you can expect an average low temperature of -15°F.

Since the USDA zone info for Carpentersville may not be accurate from year to year the actual date of last frost changes from year to year. Half of the time in Carpentersville it frosts late in the year after April 15 so just be sure to be ready to protect your delphinium in the event of a late frost.

USDA Zone Info for Carpentersville

Here is the info for USDA Zone 5b.

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

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Carpentersville

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