Larry Hodgson has published thousands of articles and 65 books over the course of his career, in both French and English. His son, Mathieu, has made it his mission to make his father’s writings available to the public. This article was originally published in the newspaper Le soleil on December 4, 1993.
If you grow a lot of houseplants, you probably have already encountered the following problem: the tips of some leaves (usually the lower ones) become dry and brown. This problem progresses slowly, with the browned area getting larger and larger, and then suddenly stops, leaving the rest of the leaf intact. Then the “disease” moves to another leaf.
However, “tip browning” is not a disease, but a problem with the growing conditions… and you almost have to be a Sherlock Holmes to discover its origin.
A browned tip can be corrected… by plastic surgery. Using sharp scissors, cut the end of the stem to a point, as on the original leaf. This treatment is effective for the time being, but is only temporary. The cut part of the leaf will dry out and you’ll have to pull out the scissors again. Moreover, the “disease” will settle on other leaves. The real cause of this symptom must be sought.
An Almost Universal Symptom
Experts recognize this affliction not as a specific problem, but as a sign of stress. The cause is easy to understand: for some reason, the plant’s sap does not reach the tip of the leaf. Without sap (and therefore without water), the tip dries up and dies. However, it is important to understand that there are several reasons why the sap is not able to circulate properly.
Problem Number 1: Air Too Dry
When the air in your home is too dry, the plant loses a lot of water through evaporation. This affects the whole plant and mainly the tips of the leaves which are thinner. The solution in this case is easy: increase the humidity of the air, with a humidifier.
Problem Number 2: Insufficient Watering
Watering can also be the cause of the problem. Some people have the habit of watering often, but not much at a time. The plant absorbs this water, starts to direct it to all its parts, but does not get enough. The water, via the sap, goes as far as possible, but not to the tips of the leaves. To correct this problem, it is important to make a habit of watering every plant abundantly, until the root ball is completely soaked with water, even if it means throwing away any excess water that accumulates in the saucer.
Problem Number 3: Mineral Accumulation
The water we give to our plants always contains soluble salts. This is even more true when fertilizers are added. To a certain extent, plants benefit from this, because they need minerals for their growth. Eventually, however, the minerals accumulate in the soil, becoming concentrated. When the concentration in the potting soil reaches an extreme point, water from the plant’s root cells is drawn out of the plant to dilute the excessive concentration of minerals in the soil. The plant then sends more water to the roots to prevent it from drying out completely… and the more fragile leaf tips bail out. A temporary solution in this case is to keep the potting soil more humid than usual, as this reduces the over-concentration of minerals in the soil.
In the long run, however, this only makes the situation worse, as the concentration increases further. You can also “leach” the potting soil by running clear water over it for a few minutes and discarding the excess. Eventually, however, you will have to consider repotting the plant in new, uncontaminated soil.
Problem Number 4: Insects
Sucking insects—aphids, mealy bugs, red spiders, etc.—pierce the fragile tissues of plants and suck the sap from them. The plant then tries to restore the balance by absorbing more water from the soil. Then it tries to restore the balance by absorbing more water from the soil. However, the tips of the leaves, being “at the end of the line”, do not always benefit from this increased moisture, because the insects, always at work, suck up the sap before it reaches them. To correct this problem, first find the insects and then eliminate them. An insecticidal soap applied once a week for a month over the entire surface of the plant will eliminate them.