When overwintering indoors, it is more common for the leaves of the black-eyed Susan to turn yellow or red and fall off. This can cause the plant to become bare at the bottom. Spider mites are to blame.
Why does the black-eyed Susan have yellow leaves?
Yellow or red leaves on the black-eyed Susan can indicate a spider mite infestation, especially if it is overwintered indoors. Reddish spots on the leaves are a sign of spider mites. Control by spraying with water and then spraying or reseeding next year.
Check leaves for spider mites
Take a close look at the discolored leaves. If you notice reddish spots on the top or bottom, spider mites are definitely responsible for the discoloration.
What you can do against spider mites
If the infestation is not too severe, you can try rinsing the plant with a jet of water and then using a commercially available spray (€16.00 on Amazon).
Most of the time it's not worth saving the Black-Eyed Susanne. Instead, grow new plants from seeds next year.
Tips & Tricks
The Black Susan grows best if you give it a suitable climbing aid. If the climbing plant can climb up it, the shoots will be more airy. This makes it easier to prevent pests and diseases.