Brown Leaves on a Cordyline

Cordylines, also referred to as ti plants, are potted or garden plants that produce long, slender, sharp-edged leaves in a variety of colours, including greens, pinks and reds. These plants make an excellent background or border plant for the garden. Although the cordyline plant is small, its leaves add a splash of colour to any garden; keeping the leaves healthy is important to keeping the cordyline alive.

Cordyline leaves grow in many colours depending on the cultivar or species that is growing in the garden. Cordyline leaves sometimes emerge as orange or yellow leaves, instead of the green that may be expected from a garden plant; while the leaves of the cordyline may approach brown in colour, this is not automatically indicative of a health problem. Watch the cordyline plant's growth to make sure leaves that look brown are healthy.

Cordyline plants are very sensitive to the presence of fluoride in the soil or water they receive. Municipal water sources often contain fluoride, which leads to fluoride toxicity in the cordyline plant. Symptoms of toxicity include browning at the edges and tips of the leaves of the plant. Avoid using water that contains fluoride to water the cordyline plant and do not plant the cordyline in perlite, according to the Penn State University Extension website.

Phytophthora nicotianae is a fungal disease that attacks cordyline plants, leading to health issues with the leaves. This disease causes lower leaves to take on a soaked appearance and develop patches of brown necrotic tissue on the leaves. As phytophthora progresses, more of the cordyline leaves will die off. Once the plant contracts this leaf spot disease, there is no treatment. Remove and destroy infected plants. The chemical dimethomorph helps prevent healthy plants from contracting the disease, according to the Penn State website.

Cordyline require moist, well-drained soil and full sun to grow properly. Cordyline plants grown in the shade are more likely to produce weak, discoloured leaves. Soil that is allowed to dry out causes the cordyline to become dehydrated, leading to unhealthy brown leaves. Symptoms of dehydration begin at the tips and edges of the leaves, as with fluoride toxicity. Water the cordyline regularly with fluoride-free water to keep the ti plant growing and healthy.