Diff: Black Spot

== Black Spot ==

== Black Spot ==

Black spot is a common fungal rose disease. It is worse where leaves stay wet, where airflow is poor, and on susceptible cultivars.

Black spot is a common fungal rose disease. It is worse where leaves stay wet, where airflow is poor, and on susceptible cultivars.

=== Signs ===

=== Signs ===

* Dark round spots, often with feathery or fibrous margins.

* Dark round spots, often with feathery or fibrous margins.

* Yellowing around spots and early leaf drop.

* Yellowing around spots and early leaf drop.

* Small purplish or dark spots can also occur on canes.

* Small purplish or dark spots can also occur on canes.

* Usually appears on leaf upper surfaces rather than as orange pustules underneath.

* Usually appears on leaf upper surfaces rather than as orange pustules underneath.

=== Look-alikes ===

=== Look-alikes ===

* Downy mildew can make angular purple or brown patches limited by leaf veins.

* Downy mildew can make angular purple or brown patches limited by leaf veins.

* Anthracnose can produce spots with pale centres and darker borders.

* Anthracnose can produce spots with pale centres and darker borders.

* Spray injury, nutrient issues, and drought stress can make irregular spotting or yellowing.

* Spray injury, nutrient issues, and drought stress can make irregular spotting or yellowing.

=== Cultural controls ===

=== Cultural controls ===

* Choose resistant cultivars where black spot is common.

* Choose resistant cultivars where black spot is common.

* Water at the soil line or early enough for foliage to dry.

* Water at the soil line or early enough for foliage to dry.

* Prune for airflow and avoid dense crowded plantings.

* Prune for airflow and avoid dense crowded plantings.

* Remove fallen diseased leaves and prune infected stems during dormant cleanup.

* Remove fallen diseased leaves and prune infected stems during dormant cleanup.

* Mulch to reduce soil splash after cleanup.

* Mulch to reduce soil splash after cleanup.

=== Direct treatment notes ===

=== Direct treatment notes ===

* Fungicides work best preventively on new foliage, not as a cure for already spotted leaves.

* Fungicides work best preventively on new foliage, not as a cure for already spotted leaves.

* Extension sources list preventive options that may include horticultural or neem oils, potassium bicarbonate, sulfur, chlorothalonil, myclobutanil, propiconazole, or tebuconazole depending on jurisdiction and product label.

* Extension sources list preventive options that may include horticultural or neem oils, potassium bicarbonate, sulfur, chlorothalonil, myclobutanil, propiconazole, or tebuconazole depending on jurisdiction and product label.

* Oils can injure water-stressed plants and should not be applied close to sulfur sprays. Follow the label interval.

* Oils can injure water-stressed plants and should not be applied close to sulfur sprays. Follow the label interval.

* UK/EU home-garden product availability changes often. Check RHS guidance, the UK HSE register, or the relevant EU/member-state register before naming or using a product.

* UK/EU home-garden product availability changes often. Check RHS guidance, the UK HSE register, or the relevant EU/member-state register before naming or using a product.

=== Sources ===

=== Sources ===

* [UC IPM: Black Spot](https://ipm.ucanr.edu/PMG/GARDEN/PLANTS/DISEASES/blackspot.html)

* [UC IPM: Black Spot](https://ipm.ucanr.edu/PMG/GARDEN/PLANTS/DISEASES/blackspot.html)

* [UC IPM: Roses diseases and abiotic disorders](https://ipm.ucanr.edu/home-and-landscape/roses-diseases-and-abiotic-disorders/)

* [UC IPM: Roses diseases and abiotic disorders](https://ipm.ucanr.edu/home-and-landscape/roses-diseases-and-abiotic-disorders/)

* [Clemson Extension: Rose Diseases](https://hgic.clemson.edu/factsheet/rose-diseases/)

* [Clemson Extension: Rose Diseases](https://hgic.clemson.edu/factsheet/rose-diseases/)

* [Penn State Extension: Rose Diseases Outdoors](https://extension.psu.edu/rose-diseases-outdoors/)

* [Penn State Extension: Rose Diseases Outdoors](https://extension.psu.edu/rose-diseases-outdoors/)

* [UK HSE: Garden home pesticide guidance](https://www.hse.gov.uk/pesticides/using-pesticides/garden-home.htm)

* [UK HSE: Garden home pesticide guidance](https://www.hse.gov.uk/pesticides/using-pesticides/garden-home.htm)

[[Category:Diseases]]

[[Category:Diseases]]

[[Category:Care]]

[[Category:Care]]