• Geraniums grow well indoors and outdoors.Geranium image by YURY MARYUNIN from Fotolia.com
  
  Geraniums (Pelargonium), also called cranesbill, are hardy perennials. The plants are mound-shaped with clusters of saucer-shaped flowers with five petals. The flowers are 1 to 2 inches wide and come in a range of pink, magenta, white, violet-blue and purple. Geraniums are long-lasting flowers and are well- suited for hanging baskets, ground covers and window boxes. Depending on variety, the plants vary in height from 6 inches to several feet.
  
  

Botrytis Blight

• Botrytis blight is caused by the fungus Botrytis cinerea. The fungus can infest geraniums during any stage of growth. It commonly occurs under high moisture and humidity in the air. It is characterized by a fuzzy, gray growth on foliage and flowers. On stems, the fungus appears as light to dark-brown lesions that gradually rot the entire stem as it grows. Infected flowers turn brown and drop prematurely. The recommended control method is to keep plants free from weeds and debris, avoid overhead watering and watering earlier than 11 a.m. Diseased plant parts need to be removed immediately. Chemical fungicides for the control of botrytis blight include iprodione, thiophanate methyl, thiophanate methyl plus iprodione, copper sulphate and azoxystrobin.
  
  

Root Rot

• Root rot is caused by the fungus Pythium or Rhizoctonia, and leads to yellow, stunted and wilted plant growth. As the fungi girdle the plant, they cause the appearance of brown to black lesions at the soil line. Infected plants also exhibit a gray or off-white, web-like growth in moist and humid conditions. The foliage starts to rot and turn brown, and large portions of the root system are decayed with glassy, brown lesions. Recommended control is the improvement of soil drainage, avoiding extensive application of nitrogen fertilizers and prompt removal of sick plants. Chemical controls include soil drenching with applicable fungicides such as metalaxyl, mefoxam, etridiazole and etriadiazole plus thiophanate methyl.
  
  

Bacterial Blight

• Bacterial blight results from the bacterial pathogen Xanthomonas campestris pv. Pelargonii. The disease starts with water-soaked, brown, V-shaped spots on the underside of the foliage. There are distinct dark veins and wilting on the leaf margins of some leaves. As the disease progresses the entire plant gets flaccid and branches start to wilt and die. Stems are blackened and shriveled. When young plants are infected they are unable to root properly and rot from their bases. Recommended control includes keeping the plants clear of debris and weeds, using healthy plants, avoiding overhead watering and removing diseased plants immediately. The chemical control for root rot is rarely needed except in larger landscapes.