Cactus
Fungi, bacteria and viruses attack cacti, the first two particularly when plants are over-watered. Fusarium rot can gain entry through a wound and cause rotting accompanied by red-violet mold. ""Helminosporium" rot" is caused by "Bipolaris cactivora" ( "Helminosporium cactivorum"); "Phytophthora" species also cause similar rotting in cacti. Fungicides may be of limited value in combating these diseases. Several viruses have been found in cacti, including cactus virus X. These appear to cause only limited visible symptoms, such as chlorotic (pale green) spots and mosaic effects (streaks and patches of paler color). However, in an "Agave" species, cactus virus X has been shown to reduce growth, particularly when the roots are dry. There are no treatments for virus diseases.
Aralia cordata
After seedlings are planted, the soil around the roots should be watered. The surroundings should be concealed with one to three inches of leaf or bark mulch, no higher than the base of the stem. It is useful to water in the morning rather than at night to prevent diseases. To prevent wilting, plants should be watered slowly and enough to achieve deep moisture, achieved by watering, waiting three minutes and watering again. To achieve water-conservation, soaker hoses, drip irrigation, distribution of mulch to prevent water evaporation, and a soil ring around the plant to retain water may be effective. It should be noted that overwatering may cause root issues. Soil drenching is effective in increasing the size of the shoots.