I have to admit that I have been a bit obnoxious (ok. I’ll admit it – I have been insufferable!) showing off my avocado tree – the one I grew all by myself from a seed. The one that started in a jar of water on my window sill and wound up a full-fledged, luxurious tree on my patio. Yes, I have been prideful, but Mother Nature has pulled me down a peg or two because my gorgeous avocado tree has been reduced to this.
If it weren’t for the single new leaf sprouting at the top I would think it had already died.
As much as I hate to admit it, the state of my avocado tree perfectly illustrates my history with most species of tropical plants. They just don’t thrive under my care. I refuse to give up though. Since I don’t seem to have been given the proverbial green thumb for indoor gardening, it looks like I’ll need to earn one for myself .
Most of the books and articles I’ve read start out by telling you which varieties of tropicals are great for novice plant parents. That seems like a reasonable place to begin, unless like many of us pandemic-driven people, you have already surrounded yourself with a myriad of tropical plants. Instead of a list of starter plants, you need to know what’s going on with the ones you already have. Here’s what I have found out in my quest for a greener thumb.
FIVE COMMON PROBLEMS AND THEIR FIXES
Distorted foliage can signal two entirely different problems. Curling leaves most commonly are the result of problems with insects. Check leaves carefully for signs of insects like aphids or white flies. If you see a fluffy white substance on the leaves, mealybugs are probably infesting the plant. Depending on the severity of the infestation, soap-based sprays can help.
High temperatures, usually from too much direct sun, can also cause foliage to curl. Try moving the plant out of direct sunlight and into a cooler spot. Give the plant a bit of extra water to replace lost moisture in its cells.
Spots on leaves can be one of the most difficult problems to diagnose because of the wide range of possible causes. A variety of bacteria, fungus, mold and virus are all culprits. Fungicides can help, as can improved air circulation for bacterial and fungal diseases. Viruses often show up as yellow spots or veining in leaves. There is no cure for virus infected plants; they should be disposed of immediately.
Misting plants with hard water can cause pale spots to appear on leaves. Soft water is preferable, but salt does eventually build up from soft water. Flush out salts at least once a month.
Dark brown spots on leaves may indicate overwatering. Make sure that the soil is not waterlogged and the pot has adequate drainage. Most plants do not want to sit in water.
Dark brown spots that eventually turn brown and crumble away signal underwatering. Make sure to water thoroughly. Surface water may not reach the root system.
My plant is totally dehydrated is usually the first thought when it hangs dejectedly in its pot. Before immediately adding water however, it’s wise to check a few things first.
Is the plant too wet? Overwatering can cause wilting.
Is the plant suffering from insect damage?
Is the plant rootbound? Roots wrapped tightly together and around the insides of the pot cannot absorb water from the soil. Often, water flows completely through a rootbound pot or sits on the top. Repotting the plant in a pot an inch or two larger allows the roots room to soak up water.
Is the plant dehydrated? In many cases the plant is indeed thirsty and after watering, the stems and leaves usually perk back up.
A tropical plant with brown-tipped leaves may be crying out for your attention. Tropicals that originate in warm, humid climates may not be able to tolerate the dry air in our homes. Try increasing the humidity directly around the plant by setting it on a pebble tray. Frequent misting may also help.
An inconsistent watering schedule can also cause the tips of leaves to crinkle and turn brown. While a tight schedule isn’t necessary, avoid long stretches between waterings followed by torrents of water. Add water until it begins to run out of the pot’s drain holes, but make sure that the plant is not sitting in water.
Too much fertilizer can also turn the tips of foliage brown. Make sure to use only the recommended frequency and amount for the size and type of plant.
YELLOW OR REDDISH LEAVES
The leaves of starving plants often turn yellow or reddish brown before they eventually fall off of the stem or branch. While many potting mediums are enriched with slow release food, eventually plants need a nutrient boost.
Cold air temperatures can cause leaves to turn colors. Remember that nighttime temperatures in the winter can be several degrees cooler near windows. Plants with yellow or reddish leaves may be asking to be moved away from windows and out of drafts.
Low light conditions that hinder photosynthesis often cause leaves to turn yellow. Moving the plant to a stronger light location can help photosynthesis to increase. Unfortunately the yellow leaves won’t turn green again.
The stress from overwatering or underwatering a plant can cause leaves to yellow. Check moisture levels at the first sign of yellow leaves.
Even perfectly healthy, perfectly positioned and perfectly cared for plants periodically shed some of their leaves. An occasional yellow or dropped leaf is not a cause for alarm.
Finally, an aside in case you’re interested. When I moved my avocado tree out of the corner, I realized that it was positioned directly under a heat vent AND it was standing in a pool of water. I hope I can save it.