When to Plant Dahlias in Highland, 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 USDA zone info for Highland can be read to estimate when it's possible to plant dahlias.


Planting Calendar for Dahlias

Frost tolerance for dahlias: Not tolerant of frost.
When to plant: After the last frost has passed.

It's probably not a good idea to plant dahlias until after the last frost has passed because they are not cold tolerant.

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

The earliest that you can plant dahlias in Highland is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant dahlias and expect a good harvest is probably August. Any later than that and your dahlias may not have a chance to fully mature. Starting your dahlias 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 Highland. It might get as low as -10°F during the coldest months of winter.

Just be sure to remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Highland and it changes from year to year. Half of the time in Highland you get a frost after April 15 so just be sure to be ready to protect your dahlias in the event of one of those late frosts.

USDA Zone Info for Highland

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 Highland

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