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.

By reviewing the USDA zone info for Vermillion it's possible to determine when it's the best time to plant delphinium.

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 means that you can plant them slightly earlier in the year than other frost tender plants.

The earliest that you can plant delphinium in Vermillion 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 fully mature. You can get started a few weeks earlier by starting your delphinium indoors.

Last Frost Date

On average all chance of frost has passed is on April 15 in Vermillion. You can expect an average low temperature of -20°F in the coldest months of winter.

Since the USDA zone info for Vermillion is just an average the actual date of last frost will vary from year to year. Since half of the time in Vermillion last frost occurs after April 15 be ready to cover your delphinium in the event of one of those late frosts.

USDA Zone Info for Vermillion

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Vermillion

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