The characteristic grass - like stems and coloured blooms of iris can be found in gardens across the United States . Although young iris plants require frequent tearing , over - watering demonstrate industrial plant often have outbreaks of fungal disease . While many of these fungous diseases make niggling long - terminus harm , bacterial diseases , such as bacterial soft rot , may prove lethal .
Fungal Leaf Spot
Didymellina leaf position is a fungous disease that causes most cases of folio stain on irises . The spots of this disease feature gray centers circumvent by reddish brown edges . If leave untreated , pip will procreate and merge , resulting in dice - back of the foliage . Puccinia iridis , commonly known as rust disease , is another fungous disease that bring out rust-brown , red slur on the leaves . Fungal leaf spots typically occur during wet weather or if the plant is over - watered . Cut back and destroy all infected foliation to avoid spreading fungal folio smear diseases . In severe cases , apply fungicides according to the direction on the product .
Bacterial Leaf Spot
Bacterial folio spots may also occur on sword lily . These spots look standardized to the Didymellina leaf spot and may also cause blight of the leaves . There is no chemical handling for bacterial foliage patch . Remove and decent throw away of all foliage affected by the disease .
Crown Rot
Sclerotium crown decomposition causes the rhizome to turn brown and balmy . White fungus look on the top of plants taint with crown rot and reddish brown , seed - similar fungal spores may appear on the skirt soil . Crown bunkum often occurs as a result of over - watering or over - fertilizing , so these action should be trim at the first foretoken of poll guff . Remove and dispose of diseased plant , as well as the surrounding soil . If the soil is not polish off , the fungus may infect nearby plant . app of chemical may forestall future attacks of this disease , but will not manipulate it once the industrial plant is infected .
Bacterial Soft Rot
Bacterial soft putrefaction enters the plant life through wounds do by the iris borer , a pesterer that onslaught irises . plant infected with bacterial voiced bunk produce a foul scent and experience a decomposition of the rhizome and leaves . The best discourse for this disease take dispatch the septic rhizomes . Dig out the plant and separate the pathological rhizomes from the healthy plant with a needlelike knife . Sterilize the knife between carving to forestall spread of the disease . Rubbing alcohol or a mixture of 1 part bleach in 10 part body of water can be used to sterilise the tongue . Replant the good for you lot of the iris , leaving the rootstock slenderly above the open of the soil . If institute too deep , the fleur-de-lis may experience root moulder . Applying pesticide will fight iris stone drill and prevent future outbreaks of bacterial soft rotting .
