Drought-stressed spider plant (Chlorophytum comosum) with many brown leaf tips. Photo: Alavanta, depositphotos
Leaves that turn brown at the tip are a common problem with houseplants. Learn what causes this problem and how to fix it in this article.
By Larry Hodgson
One of the problems often encountered with houseplants is that the tip of the leaf turns brown, dries out and dies. This mainly occurs on plants with narrow pointed leaves, like dracenas (Dracaena spp.), cordylines (Cordyline spp.) and spider plants (Chlorophytum comosum), but also on certain plants with broader leaves, such as the prayer plants (Maranta spp.) and calatheas (Calathea spp.). Carnivorous plants too are prone to leaf tip necrosis (more on that point below).
Usually when a leaf tip turns brown, it’s because it didn’t receive its share of moisture while the rest of the leaf did. But why?
There are several causes.
The 5 Most Common Causes of Brown Leaf Tips
1. Dry Air
This is a recurring problem during the winter months. If the air is dry, it’s because we heat our homes and heating reduces the air’s relative humidity. In an effort to compensate, the leaf releases massive amounts of water to transpiration, but as a result the plant’s sap doesn’t make as far as tip of the leaf simply because it is the part farthest from the cells that carry out the job of transporting sap. Since the tip is not receiving enough moisture, it tends to die.
Solution: Increase the humidity by whatever means you choose. Here are some suggestions.
If you apply insufficient water to a plant when you water or if you don’t water often enough, the leaves will be stressed by a lack of water. And again, the leaf tip, being furthest from sap transportation vessels, suffers the most, leading to tip dieback.
Plants grown in hanging baskets are more prone to damage than other plants, not only because their foliage is more exposed to drying air (see point 1), but also baskets are typically equipped with only a very small saucer that overflows readily. Therefore, the caretaker (you) tends to water more cautiously, thus less abundantly, to prevent spillage, leading to a plant that is constantly suffering from water stress. And again, this kind of stress shows most obviously as damage to the tip of the leaves.
Solution: Water deeply enough to moisten the entire root ball and repeat when the soil is dry to the touch. If the soil dries out again only 4 or 5 days after watering, it would be wise to repot in a larger pot. As for hanging baskets, instead of watering them sparingly, take the basket down and literally soak it in water so that the soil can truly absorb the amount of water it needs.
As bizarre as it may seem, too much water can just as easily cause brown leaf tips as too little. That’s because, if the soil in the pot is constantly wet, the roots begin to die back.* And if the roots die, less water will make it as far as the foliage … and once again, it’s the leaf tip that suffers most, causing dieback.
*There are few houseplants that are semi-aquatic: they prefer that their roots constantly soak in water, including umbrella sedge (Cyperus alternifolius). For these exceptions to the rule, overwatering simply isn’t possible and so won’t cause leaf tips to die.
For any houseplant that isn’t semi-aquatic, apply the Golden Rule of Watering: wait until the soil is dry before watering again. To see if watering is necessary, sink a finger into the growing mix up to the second joint. If it feels moist, don’t water. Wait until it does feel dry, then water abundantly, soaking the entire root ball. If the soil mix regularly goes from moist to just slightly dry, you’ll never overwater.
If you fear that your overwatering has gone too far and that the excess moisture has killed the roots of your plant (you’ll probably notice a smell of rot if you sniff the soil), things are more serious. Depot the plant, cut off any rotting roots, repot in fresh soil … and cross your fingers. When the root system of a plant has started to rot, it’s not always possible to save it.
4. Contaminated Soil
Over time, mineral salts coming from hard water, treated water and fertilizer accumulate in the soil of houseplants and gradually poison it, causing the roots to die back. If the roots die back, so will the leaves, because they won’t be receiving their full share of water. Again, the leaf tip takes the brunt of the damage.
Solution: Leach the soil of your houseplants at least 2 or 3 times a year or put them outside for the summer so the rain can leach them. And repot regularly, changing the soil when you do so. And don’t use water softened using salts to water plants at all.
If you tend to fertilize too much, you create a situation similar to a soil contaminated with mineral salts: excess minerals tend to kill root tips leading to decreased water absorption and less water making it to the leaf tips, so they die back.
Solution: Learn to fertilize your plants with great care and never to excess. The usual rule for houseplants is to apply fertilizer at a quarter of the indicated rate and even then, only during the growing season.
Carnivorous Plants: A Special Case
Most carnivorous plants come from bogs that are extremely poor in minerals and will not tolerate the presence of minerals when you grow them indoors. If they are given minerals, their leaves die back. These plants need special care to remain green and healthy and that includes:
- Watering with mineral-free water (rainwater or distilled water);
- No application of fertilizer (very concentrated in minerals) to their soil;
- Mineral-free soil (usually sphagnum moss).
Chlorine Damage: Is It Really the 6th Cause?
You will read almost everywhere (it’s one of the more pervasive garden myths) that some houseplants, especially dracenas, cordylines, spider plants, and carnivorous plants, are very susceptible the accumulation of chlorine in the soil and this not only leads to browning leaf tips, but is actually the main cause of leaf browning. If your water comes from any kind of municipal system, it probably contains chlorine, so gardeners are commonly given advice on how to avoid applying any chlorine to their plants.
However, this really isn’t a problem. Chlorine levels in drinking water are never at dangerous levels for plants and simply won’t cause damage. Nor is there any need to leave water in an open container for 24 hours before using it to allow chlorine to evaporate. That will in fact, concentrate the chlorine very slightly rather than reduce it, although that is of no importance.
Solution: Just use whatever water source of water is convenient to you (except when it is treated with salt-base water softeners which should never be used on plants).
When the Damage is Done
Once the tip of a leaf is dead and brown, nothing will bring it back to life, regardless of treatment you give to the plant. If its presence bothers you, you simply cut off the dead tip with pruning shears or scissors. But I have an even more laidback solution. I suggest you apply the “15 pace rule”: step back 15 paces and you won’t see that the leaf tips are brown. Problem solved!