Houseplant Care: Tipburn Plagues Houseplants

The ends of the leaves simply become brown and die while the rest of the plant appears healthy and grows normally. It is mainly of concern because it detracts from the decorative quality of a plant, but does not mean that the plant is about to die. Some plants are more likely to develop tipburn than others. It is usually most common on certain plants belonging to the lily family. One of these is the spider, or airplane plant. Tipburn is usually more severe on the variegated form than on the solid green type.

Some dracaenas are also susceptible, particularly "Dracaena marginata," known as the dragon tree. Here too, the variegated form - known as rainbow dracaena - usually develops brown tips more severely than the green form. Another close relative of the dracaena is the pleomele. Two kinds that are increasingly popular are the Malaysian dracaena, a rather upright-growing plant with sword-shaped leaves clustered along each stem, and the lance dracaena, a low-growing plant with individual dark green lance-shaped leaves.

The growing popularity of pleomeles is due to their adaptability to low light conditions, but they too, are subject to tipburn. Cordylines, known as red dracaenas or ti plants and also from the lily family, sometimes exhibit tipburn. Again the condition seems more severe on the red-leaf than on the green-leaf forms. Cultural conditions may first be suspected when plants exhibit this problem, and poor culture can certainly lead to tipburn on many other plants, as well as members of the lily family.

Too little light or water, too much water or fertilizer and low humidity are the common causes. These cultural problems, however, usually also lead to poor growth in other ways. Sometimes growth is good and proper care has been given, but still plants develop tipburn. Recent research has indicated that excess fluoride in water may be suspected when this occurs. This is particularly the case when these plants of the lily family are involved. They seem to be more sensitive than most plants, so are quick to develop the problem. Fluoride is not fatal, and the tipburn is usually the limit of the damage.

Where fluoride is added for tooth decay control, the benefits of this use seem to outweigh the tipburn caused ona relatively small number of sensitive plants. In this situation, rainwater could be used or distilled water purchased for exclusive use on these plants. Some potting materials and fertilizers may contain fluoride and should be avoided in potting mix to be used for these plants. However, one of these liquid fertilizers normally used for houseplant fertilization is no problem. Perlite, a light weight, white material used as a soil additive to improve aeration and drainage may also contain fluoride.

For these plants coarse sand or calcined clay (material used for cat litter) could be substituted. Since fluoride may be tied up in less acid soils, the problem may be reduced if the soil pH is kept above 6. However, often the simplest and most inexpensive approach to the problem is to cut off the brown tips. A thin brown line may remain at the end of each leaf where the cut has been made, but the plant will look better.

Houseplants for Dummies, by Larry Hodgson.