Plant care guide
Dark Brown Spots on English Ivy: Bacterial or Fungal?
Updated
Why does my English ivy have brown spots?
Dark brown to black spots on English ivy that start pale and water-soaked, often with red or yellow margins, point to bacterial leaf spot (Xanthomonas hortorum pv. hederae). Large tan to brown spots with black specks and no red edge suggest a fungal leaf spot. Papery tan blotches without a water-soaked start are usually injury, not infection.
What to do first
Isolate the plant, hold a spotted leaf up to the light, and look for a water-soaked or oily ring. Pick off spotted leaves while they are dry, stop wetting the foliage, water the mix early in the day, and give the plant more air movement.
Dark spots spreading across an ivy you have trained for months are worrying. English ivy gets a few leaf spot diseases, and one of them, bacterial leaf spot, is common and spreads with water. The spot’s first stage and its edge tell you which one you have.
NC State Extension’s Hedera helix profile lists leaf spots, bacterial leaf spot, canker, stem rot and powdery mildew among its diseases. It also lists aphids, mealybugs, spider mites and scale.
Sort the spot
| What you see | Likely cause |
|---|---|
| Light green, water-soaked spots that turn brown to brownish-black, red margins on older leaves | Bacterial leaf spot |
| Oily ring around the spot when held to the light; old centres falling out | Bacterial leaf spot |
| Black, shrivelled leaf stalks and blackened tips | Bacterial infection of petioles and stems |
| Large tan to brown spots with tiny black specks, no red margin | Fungal leaf spot (Colletotrichum) |
| Circular to irregular tan spots with concentric rings | Fungal leaf spot (Phyllosticta, Glomerella) |
| Tan to brown papery blotches at margins or across leaves, no water-soaked stage | Cold or winter injury |
| Yellow stippling, fine webbing underneath | Spider mites |
Bacterial leaf spot
The Missouri Botanical Garden’s English ivy leaf spot page names the cause as Xanthomonas hortorum pv. hederae. Spots begin light green and water-soaked, then turn brown or brownish-black in the centre. Mature leaves show red margins. Infected leaf stalks turn black, and tips can blacken and die.
UF/IFAS Extension’s English ivy disease guide (PP339) gives a useful check. Hold the leaf up to the light, and you may see an oily circle around the lesion. Yellow halos can appear, and old lesions may drop their papery centres, leaving a shot-hole look. UF says the bacteria enter through leaf pores and wounds and move to new leaves in splashing water. Warm, humid periods favour them.
The Connecticut Agricultural Experiment Station describes the spots as pale green, irregular and water-soaked, with yellow or sometimes translucent borders. Oregon State University’s PNW disease handbook adds that the bacterium can cause stem cankers.
Fungal spots and injury
MBG separates fungal leaf spot by its large tan to brown spots, the lack of red margins, and black specks of fungal fruiting bodies. UF/IFAS describes Colletotrichum spots starting small and light brown, then enlarging to dark brown with dark structures in rings. CAES describes Phyllosticta and Glomerella spots as tan, circular to irregular, often ringed.
CAES lists winter injury as tan to brown papery blotches. On an indoor ivy, a cold window or draught is the likely equivalent. Injury does not start water-soaked and does not keep spreading once the cause is removed.
What to do
- Isolate the plant from other ivies and houseplants.
- Remove spotted leaves while they are dry. UF/IFAS advises this, and MBG suggests destroying infected leaves and stems. Clean your scissors between cuts.
- Keep water off the leaves. All four disease sources say to avoid overhead watering. Water the mix early in the day, as MBG advises.
- Improve air movement. UF and CAES both recommend better airflow. Space the pot away from other plants.
- Consider copper only for a valued plant. MBG says copper fungicides are generally effective. Oregon State warns that chemical control of bacterial spot is difficult and often ineffective. Follow the label, and discard a heavily infected plant, as the PNW handbook advises.
Clemson Extension’s houseplant disorders factsheet notes that bacterial spots on houseplants stop enlarging in drier conditions and dry out reddish-brown. Keeping foliage dry is your main control indoors.
Prevention
Take cuttings only from clean stems; UF/IFAS stresses clean propagation stock. Water from below or at the mix surface. If you also see stippling and webbing, treat for mites first, since CAES lists spider mites on ivy and advises maintaining humidity.
Spotted leaves will not recover. Judge progress by whether new leaves stay clean. For more on telling disease spots from injury on any houseplant, see brown spots on houseplant leaves and leaf spot diseases of houseplants.
Related guides
Other english ivy problems we cover: spider mites.
References
- UF/IFAS Extension: English Ivy (Hedera helix): Identification and Control of Diseases in Commercial Greenhouse Production and in Landscapes (PP339)
- Missouri Botanical Garden: Leaf Spots of English Ivy
- Oregon State University, PNW Plant Disease Management Handbook: Ivy (Hedera helix), Bacterial Leaf Spot and Stem Canker
- Connecticut Agricultural Experiment Station: Ivy, English (Hedera), Plant Pest Handbook
- NC State Extension Gardener Plant Toolbox: Hedera helix
- Clemson Cooperative Extension HGIC 2251: Houseplant Diseases & Disorders
How this guide was put together: UF/IFAS Extension, Missouri Botanical Garden, Oregon State University's PNW Plant Disease Management Handbook, Connecticut Agricultural Experiment Station, NC State Extension and Clemson Extension guidance.