When to Plant Delphinium in Plainfield, IL

Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. 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 Plainfield should be determined by referring to 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.

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

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant delphinium
Possibly ok, but a risky time to plant delphinium
Probably not a good time to plant delphinium

The earliest that you can plant delphinium in Plainfield 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. If you are starting your delphinium indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

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

Remember that the actual date of last frost is just an average because it is based on the USDA zone info for Plainfield and it is different every year. Half of the time in Plainfield you get a frost after April 15 so make sure that you are prepared to protect your delphinium if you have a surprise late frost.

USDA Zone Info for Plainfield

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 Plainfield

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