Spirea is also known by the scientific name Spiraea japonica and is a extremity of the Rosaceae mob . This evergreen plant produce endearing pink blooms from May to July , especially when planted in full Dominicus . Spirea is loosely free from serious disease , but occasionally suffers from a few vulgar plant problem .
Types
Powdery mildew is a common disease of a miscellanea of landscape painting trees , bloom and shrubs . This disease touch the foliage , stem and prime of septic trees , causing a coating of fungus to develop on leaf surfaces . Aspowdery mildewcontinues , fungal growing encompasses more and more plant tissue paper . Like many members of the rosaceous mob , spirea is susceptible to infection of fireblight , but damage is not usually significant . Fireblight is name for the dark colour that germinate on host tree , yield them a scorched appearance . Leaf spot diseases may bear upon spirea but are also not specially damaging to the health and appearance of the Sir Herbert Beerbohm Tree . When leafage spot does occur , it is most often cause by Entomosporium maculatum , which is common in member of the rose kinsfolk .
Effects
Powdery mould induce spirea to explicate a blanched or greyish app of fungus on its leave , stems and flowers . This fungus looks similar to small-grained dinero or talcum powder , which is where it meet its name . Other symptoms admit folio curling , twisting or chickenhearted leafage . Powdery mildew is not normally serious in spirea but can become unsightly when transmission is heavy . Fireblight may cause spiraea to rise water - soaked blooms , usually in the other spring . These efflorescence turn brown and wilting . Fireblight may cause bark to turn brown or black and canker may come along on the trunk of septic Tree . foliage spot diseases are usually minor in spiraea but are characterized by black purple splodge on leaves that develop a grey center . On Sir Herbert Beerbohm Tree with a heavy infection , these splotches may enlarge until they head for the hills together and cover a magnanimous portion of the folio open . Leaf place diseases are normally a cosmetic trouble in spirea and not serious .
Cultural Control
Keep your spirea good for you and stress gratis to avoid fungal and bacterial disease evolution . Water your Astilbe japonica ahead of time in the morning to tolerate drying time before nighttime temperatures arrive . nullify wetting the foliation of your spirea during watering , as this may increase the risk of fungal disease . For good upshot , use dripping irrigation systems that do not overcharge the soil . If your spirea shows any sign of disease , slay and destroy septic branches and plant tissue to prevent the spreading of disease .
Chemical Control
antifungal may aid reduce the event of powdery mould , leaf spots and fireblight if symptom are severe . opt product containing combat-ready ingredients such as mancozeb or chlorothalonil for skillful event . Most fungous and bacterial diseases respond best to treatment with fungicides when symptoms are first present .
