When to Plant Larkspur in Harrisburg, IL

Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A way of getting a good idea when you can plant larkspur is to look at the USDA zone info for Harrisburg.


Planting Calendar for Larkspur

Frost tolerance for larkspur: Very tolerant of frost.
When to plant: Up to 7 weeks before last frost.

Since larkspur are very cold tolerant you can plant them a lot earlier in the year than more sensitive plants.

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

The earliest that you can plant larkspur in Harrisburg is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant larkspur and expect a good harvest is probably September. If you wait any later than that and your larkspur may not have a chance to grow to maturity. Starting your larkspur indoors is a great way to get them started a little bit earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Harrisburg. In the coldest months of winter you should expect an average low temperature of -5°F.

Always keep in mind that USDA zone info for Harrisburg is an average and the actual date of last frost changes from year to year. Half of the time in Harrisburg you get surprised by a frost after April 15 so just be sure to be ready to cover your larkspur in the event of one of those late frosts.

USDA Zone Info for Harrisburg

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)April 15
Average Date of First Frost (fall)October 15
Lowest Expected Low-5°F
Highest Expected Low0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in Harrisburg

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