One of the first steps you take when you are figuring out your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The best time to plant delphinium in Vincennes should be determined 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 are one of those plants that can tolerate a tiny bit of cold weather which means that you can plant them slightly earlier than other plants that might not handle the cold.

The earliest that you can plant delphinium in Vincennes 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 grow to maturity. 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 Vincennes. In the coldest months of winter you can expect an average low temperature of -10°F.

It's important to remember that USDA zone info for Vincennes is an average and the actual date of last frost will vary from year to year. Half of the time in Vincennes you get a frost after April 15 so make sure that you are ready to cover your delphinium if you have a surprise late frost.

USDA Zone Info for Vincennes

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 Vincennes

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