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.

One way of determining when to plant delphinium is to consult the USDA zone info for Springfield.

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.

You can plant delphinium a bit earlier in the year because they are one of those plants that can tolerate a tiny bit of cold weather.

The earliest that you can plant delphinium in Springfield 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. If you wait 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 Springfield the average date of last frost happens on April 15. It might get as low as -10°F during the coldest months of winter.

It's important to remember that USDA zone info for Springfield may not be accurate from year to year and the actual date of last frost changes from year to year. Half of the time in Springfield you get surprised by a frost after April 15 so always be ready to cover your delphinium if you have a surprise late frost.

USDA Zone Info for Springfield

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 Springfield

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