Houseplants - Brown Tips and Salt Burn

Why do the tips of my houseplants turn brown? The answer is there can be several reasons but, I thought I would share with you about one particular reason that I discovered a few years back.

Certain houseplants are very prone to brown leaf tips more so than others. Two that come to readily to mind are Spider Plant (no they don’t have spiders in them) and Lucky Bamboo (and I can't say it's ever brought me any luck). For years I’ve had the same problem with my plants and I’ve asked every “plant person” I’ve come in contact with the same questions; What am I doing wrong? How do I make the brown tips go away? The answer I received most often was “I don’t know”.

To me (and most folks) the obvious answers are water and fertilizer more. Turns out that both are the very worst things I could have done. More water will only cause the leaves to turn yellow and/or mushy making the plant look all the worse and eventually die. More fertilizer caused more and larger brown tips.

After asking every plant person I met (both professional and hobbyist) I finally stumbled on an answer that made sense and turns out the prescribed answer really does work.

Brown tips on plants such as Lucky Bamboo and Spider Plant are most often caused by a thing called ‘salt burn’. Salt burn happens when the roots of the plant come in contact with more salt in the soil then they can cope with. This causes small, often totally unnoticeable burns on the roots that in turn keep the roots from doing their job - taking up water and nutrients. Although it's rarely fatal it is very unsightly.

Most all commercial fertilizers are made up of salts such as potassium and nitrogen (the chemical used to green up your lawn grass). Water from City supplies are treated with chlorine; another salt. For the most part the first two are good for your plants, the third not so much. These chemicals are also good because without them we would be a very hungry nation and without chlorine in our water we would be a very sick nation. But there are certain plants (Bamboo and Spider plants are only two) that are negatively affected by these chemicals and with a little knowledge and training we can lean to recognize the problem and treat it properly.

The best treatment for salt sensitive plants is to avoid it by feeding with natural fertilizers only when necessary (which is much less often than you might think) and by using aged water.

The truth is that Lucky Bamboo and Spider plant only need to be fertilized once a year at the beginning of the growing season, and again about mid-July if you must. Use only naturally occurring fertilizers such as fish emulsion at ½ to ¼ strength, you can also water with compost tea but again I would make it weak and keep it down to 2 times a year at the very most. Or you can top dress (sprinkle the top of the soil) with worm castings, also called vermicompost.

Ageing your water by filling the watering can and allowing it to sit open for at least 24 hours will allow the chlorine to evaporate off. When you water be sure to allow the water to soak the soil completely and run through the pot for several seconds each time you water. This will help to wash away any salt build up.

Another way to recognize salt build up is by looking at soil in the top of your pots. If, when dry, it appears yellow and/or white and crusty then you have salt build up. This often happens in African violets that are fertilized with commercial fertilizers. The best way to deal with this is to scrape the bad soil from the surface being sure to get all the yellow/white crystals, replace it with fresh soil and water thoroughly with aged water.

The brown tips on the houseplants in the pictures are the result of a long vaction under the trees being watered with the hose. Even us plant folks take the shortcut sometimes.

Do you have a houseplant related question? Email me at sojourn1960@hotmail and I’ll try to help you find the answer.



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