If the ivy turns brown, this can be caused by bacteria or a fungal disease. You can find out here which diseases there are.
Ivy is a hardy and undemanding climber that tends to become rampant and you need to keep it in check. However, there are also susceptible varieties. For example, it can happen that the ivy does not survive a hard winter. But it also has a lot of problems with drought. Pests and fungi can also cause the leaves to turn brown and even die off completely over time.
Causes of Brown Leaves & Treatment Options
» Drought:
The most common cause of brown ivy leaves is drought. If the ivy is in too sunny a place, it can quickly suffer from a lack of water. The result: the leaves turn brown. Therefore, always plant the ivy in a semi-shady to shady spot.
If the summer is very hot, it is best to water the ivy more intensively. If the plant is already very high, spray the leaves with water. But only when the sky is overcast, otherwise the leaves could burn.
» Ivy variety is not hardy:
Not every ivy variety is hardy. If this is the case with your ivy, don't be surprised if the plant develops brown leaves over the winter. This is a sign that the leaves have frozen. You must always plant these varieties in a place where the ground does not freeze in winter. Otherwise, rely on very hardy varieties such as Hedera colchica Sulfur Heart, Hedera helix Modern Times and Hedera Helix B altica.
» Fungal diseases:
Focal spot disease:
If the leaves only turn brown in certain areas, this can be due to bacteria or a fungal disease. The focal spot disease (Colletotrichum trichellum) manifests itself e.g. by gray to brown spots with a fungal covering and small fruiting bodies.
If you see an infestation with this fungus, cut back the plant heavily and remove the fallen leaves.
Ivy Cancer:
But the so-called ivy canker (Xanthomonas campestris pv. hederae) can also cause problems for the plant. This is initially expressed by smallspots on the leaves. As the process progresses, black spots with a reddish-brown edge form, which dry up and fall out.
To get rid of this fungal disease, you should quickly remove the affected parts of the plant. Then thin out the plant well and do not rinse it off again, because the fungus spreads through sprayed water. It is also important that you disinfect your cutting tool regularly, as the bacteria also settle there.
» Pests:
Common spider mite:
Pests can also cause ivy leaves to turn brown. Among other things, the common spider mite, for example, can be to blame for the ivy in the living room turning brown. It spreads on the underside of the leaves, where it then deprives the plant of nutrients. First, the leaves turn yellowish. If the infestation is severe, they will turn brown and dry up.
As the pests multiply in dry, warm air, do not place the plant too close to the heater. Also spray the ivy regularly with water as a preventive measure. If none of this helps, then it is best to take action against the pests with a non-toxic preparation based on rapeseed oil. Recommended is e.g. Naturen Schädlingsfrei (available here). The fine drops of oil clog the animals' breathing openings so that they suffocate in no time.
scale insects:
Even scale insects like to tamper with the ivy. You can recognize an infestation, for example, by the so-called honeydew on the upper side of the leaf. This is a sticky substance. The scale insects themselves settle on the underside of the leaf. If the plant is heavily infested, the leaves will turn brown.
To get rid of the pests, you can spray the ivy with a solution of water, soft soap and alcohol. Alternatively, you can also use a rapeseed oil-based preparation to combat the pests.