We Are Having Problems With Our Dahlias Their Leaves Are Turning Black.

Question

We are growing them from tubers and all of them are getting black leaves.

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Answer 1

The pots look very small for dahlias. The tubers need lots of room to increase. You might consider repotting.

The black leaves may be from overwatering or not enough drainage holes. Dahlias need very well-drained soil. Remove the black leaves and let the soil dry out between watering. You can lightly work more perlite into the soil to help with drainage.

These articles should help:

https://extension.psu.edu/dahlia-diseases

https://www.uidaho.edu/-/media/UIdaho-Responsive/Files/Extension/county/Kootenai/gardening/perennials/growing-and-caring-for-dahlias.pdf

https://extension.psu.edu/the-dirt-on-dahlias

https://www.gardeningknowhow.com/ornamental/bulbs/dahlia/tips-dahlia-planting.htm