When to Plant Dahlias in Sullivan, IN

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

You should be able to estimate when it's the best time to plant dahlias by referring to the USDA zone info for Sullivan.


Planting Calendar for Dahlias

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

Since dahlias are not cold tolerant you really should wait until after all chance of frost has passed before you can plant them.

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 Sullivan 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. You probably don't want to wait any later than that or else your dahlias may not have a chance to fully mature. You can get started a few weeks earlier by starting your dahlias indoors.

Last Frost Date

The average date of last frost is April 15 in Sullivan. You can expect an average low temperature of 5°F in the coldest months of winter.

Since the USDA zone info for Sullivan may not be accurate from year to year the actual date of last frost is different every year. Half of the time in Sullivan there is a last frost after April 15 so just be sure to be ready to protect your dahlias if you have a surprise late frost.

USDA Zone Info for Sullivan

Here is the info for USDA Zone 7b.

Average Date of Last Frost (spring)April 15
Average Date of First Frost (fall)October 15
Lowest Expected Low5°F
Highest Expected Low10°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 10°F.

Plants to Grow in Sullivan

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