What follows is a detailed list of avoidable conditions that favor plant disease. Plants Not Adapted To Site Plants not adapted to where they are planted will be weak and vulnerable o disease. Common examples are full sun plants such as roses or citrus planted in a shady area. Likewise, plants such as begonia, which thrive in the shade, are stressed and disease prone when planted in full sun sites. Plants adapted to acid soils, such as gardenia and ixora, will suffer nutritional deficiencies when grown in alkaline soils.
Some plants are very susceptible to certain problems.
Pittosporum is susceptible to leaf spots and root rots. Roses are prone to black spot disease. Indian hawthorn and Aralia are susceptible to leaf spot. Spider plants, dracaenas and in general plants in the maranta family are quite susceptible to leaf tip scorch when exposed to fluoride. Tomato and pepper are susceptible to root-knot nematodes and viruses.