Houseplants are prized for their foliage, so it can be especially distressing to realize the leaves on your houseplant are beginning to drop off one by one. Although sometimes leaf drop can come down to life cycle or seasonal changes, other more serious causes can contribute to leaf loss. Why is my houseplant losing its leaves?
Here are the 11 most common reasons houseplants lose their leaves:
- Plant stress
- Seasonal shifts
- Pest infestation
- Humidity sensitivity
- Indoor temperature changes
- The pot is too small
- Lack of nutrients
Yes, those are 11 different reasons why your houseplant might shed its leaves. Ahead, I’ll walk you through each of the above causes so you can narrow down which one, or more, you think is responsible for your naked plant. I’ll also provide some tips for preventing future leaf drop.
Here’s Why Houseplants Lose Leaves
Plant Stress or Transplant Shock
When you’re under the gun with a big work project, how do you feel? Not so great, right?
Plants can experience stress as well. Since they don’t have jobs, it’s not their bosses that can stress them out. Instead, other factors can upset your houseplant. One of the most common plant stressors is moving your plant.
That goes for both taking your houseplant out of its current pot and putting it in a new one as well as moving your home or office. These causes of stress are both referred to as transplant shock. Once your plant adjusts to its new home, it should stop shedding leaves and showing other signs of stress.
Just make sure its new conditions closely replicate the old ones. Your plant can go into shock if its light or temperature is drastically different. This will cause your plant to lose even more leaves when it doesn’t have that many to spare.
If you have a tree or several in your front yard, then you see how the tree changes throughout the year. By winter, it’s bare, and then in the spring, it’s regrowing. Your houseplant–despite that it lives indoors–might follow these seasonal patterns as well, at least to an extent.
Your indoor plant shouldn’t lose all its leaves in the winter, but if a few come off and it’s not due to any of the other reasons on the list above, don’t worry. It’s normal, and before you know it, your houseplant’s active growing season will begin and its leaves will regrow.
Okay, now I want to get into some serious reasons why your plant might be losing its leaves, one of these reasons being disease. Here are some plant diseases to be on the lookout for if your plant is shedding.
Houseplant with Root Rot
I’ll start with a common plant disease, root rot. This disease from overwatering (which I’ll talk more about shortly) oversaturates the roots so they’re not getting any oxygen, only water.
The roots die, and when that happens enough, the damage begins spreading to the rest of the plant. Your houseplant’s leaves may become discolored and wilt before falling off. Root rot will kill your plant without intervention on your part.
Houseplant with Bacterial Leaf Spot
If your plant prefers cooler temperatures, just make sure things don’t get too cold and especially not wet. These conditions could encourage the proliferation of bacterial leaf spot.
As the bacteria spread across your plant (which can happen in a few hours), you’ll notice symptoms throughout your plant’s leaves.
First, the leaves will have black or very dark brown spots. Each spot may have a yellow ring encircling it.
The leaf spot can become dried and fall away, as can the entire leaf. Bacterial leaf spot, despite its name, can affect flowers, buds, and shoots too.
Houseplant with Anthracnose
Fungi such as Gloeosporium and Colletotrichum cause anthracnose, a leaf disease. Wet, cool weather can accelerate the degree of infection much like bacterial leaf spot.
You’ll notice mostly leaf discoloration with anthracnose, including yellowing and browning of the leaves. Before the leaves die and certainly after they’re dead, they’re likely to fall off.
Houseplant With a Pest Infestation
If you haven’t noticed any strange spots or weird colors from your houseplant but its leaves are still coming off, it could very well be due to pests within its pot. Three insects are known for causing plant leaf drop: scale, spider mites, and mealybugs.
Scale is a teeny-tiny white insect that releases wax to safeguard itself from predators. Not all scales necessarily need a partner to mate, which means they can reproduce in huge numbers and wreak havoc on your plant.
Spider mites love houseplants as homes, as they can make their silky webs on the leaves of a plant. When the time comes to eat, a spider mite will pierce into your plant’s leaves and dig into the cells.
This dries up the leaves and will eventually cause them to fall off. Oh, and even if you have a pretty exotic plant species, spider mites probably don’t care. They will eat several hundred different plant species.
Mealybugs prefer warm, moist environments, so watch your humidity-loving plants especially, including subtropical and greenhouse plants. Once the mealybug has established its home and begins sucking up the juices of a plant’s leaves, the insect can kickstart plant diseases.
Overwatering Your Houseplant
I mentioned before that root rot from overwatering is one way your houseplant’s leaves can shed. Even before root rot takes hold, the leaves can still suffer.
Here’s how it usually works. When you water a houseplant, the water on its leaves will evaporate. When the plant needs more water, it calls on the supply in the roots. This is transpiration.
Indoor plants don’t use a lot of the water you feed them. Roughly one to three percent of that water is retained.
The rest of it is transpired or guttated. Guttation occurs at night or very early in the morning after the stomata close up and transpiration stops.
As water builds up in the plant, the pressure does as well. This causes water to seep through glands called hydathodes. The plant appears to be crying or sweating, but it’s doing neither. It’s guttating!
To Learn More: Why Is My Swiss Cheese Plant (Monstera Deliciosa) Sweating?
Okay, so that’s what should happen. When you overwater your houseplant, the water flushes through to the leaves in excess quantities. The cellular structure of the leaves is bloated and full.
When a person overwaters their houseplant, the excess water inside the leaves can cause the leaves to weigh more than the stems or branches can hold and cause the leaves to drop. Also, if you touched the leaves, they’d be mushy like the roots of the plant are as well. Mushy leaves cannot structurally support themselves, so they’ll fall over sooner than later.
Underwatering Your Houseplant
Unless we’re talking about succulents, then few plants are meant to go weeks and weeks without so much as a drop of water. In this situation, the opposite of what I described above transpires.
The plant has no water, so it’s parched from the inside out. The leaves will turn yellow first before blackening or browning around the tips. Touching any of the leaves will reveal a very crispy texture.
Your plant is weak in this state. Watering it now and then getting it on a regular schedule could help, but without any water, its leaves are going to start falling off in quick succession. Your plant could also die.
Although some plants are more lenient if their environment is colder and drier than what they prefer, lots of other indoor plants are not as forgiving. Here’s a list of tropical plants that need humidity to thrive:
- Miniature roses
- African violets
Cyclamen must have moderate humidity and temperatures of 55 to 70 degrees Fahrenheit. Gloxinia requires relative humidity over 70 percent, which is quite toasty.
Miniature roses will do well with average relative humidity between 40 and 50 percent. The African violet and gardenia like slightly higher humidity at 50 to 60 percent.
When the humidity drops below those requirements, these sensitive plants will not respond favorably. To indicate to you that hey, they need a humidifier or some misting, the houseplant will begin dropping its leaves.
Even humidity-loving plants outside of those on the list above could be sensitive if their humidity drops under a certain level.
Indoor Temperature Changes
Sudden temperature shifts can be a shocking and stressful experience for houseplants. The good news is that since your plant is growing safely in your home or office that it’s less susceptible to fluctuating weather patterns.
The bad news is that you can create temperature extremes in your own home, often without realizing it.
If your indoor garden is anywhere near your home’s air vents, then your plants are right in the line of fire, so to speak. In the winter, each time your heater kicks on, your plants will get a huge blast of warm air.
Sure, some plants don’t mind a little warmth, but not like this. Then, as the temperatures begin warming up in the summer, you run the air conditioner all day.
The shifts between comfortable room temperature and then very hot or very cold temps would make almost any houseplant miserable. If the temperatures don’t cause the plant’s leaves to shed, then the hard air gusts from the air conditioner will.
Be aware of other sources of heat or cold throughout your home. For example, don’t put your houseplant on your portable freezer.
Placing the plant on a fridge isn’t wise either. This is usually way too high up, and your plant could tip over if you’re not careful. The heat from the internal components of the fridge can also make your plant drop its leaves.
Houseplant is in The Wrong Size Container (The Pot Is Too Small)
Plants are almost always growing. Well, ideally, they are anyway. That goes for the roots, stems, and leaves. When a plant is constricted because its pot is far too small for it, it doesn’t necessarily stop growing, at least not at first. If the roots become rootbound and choke themselves off, then yes, growth will stop.
Since your houseplant is still trying to grow new leaves despite that its home is a little too tight, it can’t devote energy to maintaining its current leaves at the same time. The old leaves will thus fall off to make room for the new.
Lack of Nutrients
Have you fertilized your plant lately? If the answer is no and your plant is in the midst of its active growing season, it might not be too late. The three main nutrient requirements of houseplants are nitrogen, potassium, and phosphorus. How much of each nutrient a plant needs is dependent on the plant species, but this is not something you want to guess at.
Using the wrong fertilizer mix is just as bad as not fertilizing at all, as your plant isn’t getting the nutrients it must have for survival. Without the three main nutrients, growth can stop and the leaves of your plant can turn all sorts of colors, from dark green to yellow and even pink in the case of a nutrient deficiency. The leaves may shed as well.
Just as both overwatering and underwatering your houseplant is bad for it, so too is underfertilizing and overfertilizing. An overfertilized plant has received nutrient overload. Yes, too much of a good thing can become a bad thing, and this proves it. If you’re fertilizing more than once a month, then your plant is probably going to be in trouble.
Overfertilized houseplants may have symptoms such as dead seedlings, halted growth, flower shedding, black roots, and crusty soil. The leaves will become yellow and brown. They may wilt before falling off or they’ll shed with little fanfare.
To Learn More About Over Fertilizing: How to Fix Using Too Much Miracle-Gro on Your Plants
How to Prevent Your Plant from Losing Its Leaves
Whew, that sure was a lot that I just covered. I hope the information from the last section helped you identify which plant care mistake you might be making that’s costing your plant its leaves.
Now it’s time to talk about how you can remediate the issue and prevent recurrences of leaf drop.
Move Your Plant Only as Often as You Have To
There will come a day when your houseplant graduates from its pot and needs a new one. That can take a year for fast-growing plants and two or three years for the slow growers.
You’ll know when it’s time because your plant will look top-heavy. You might not even be able to see the pot anymore because the plant has grown that large.
At that point, your plant has to upgrade its home. Leaving the plant where it is will impede the roots from growing. They could become rootbound, and you know already that that’s not what you want.
However, moving your plant any more often is not recommended. You’re causing the plant stress for no good reason. Sure, most houseplants recover from stress and shock, but not with their full foliage.
Know the Signs of Plant Disease and Treat Immediately
Every week or so, make sure you’re inspecting your houseplant for visible changes. Check its soil, stems, foliage, and flowers. If anything seems amiss to you, keep an eye on it.
Most plant diseases can start very small, such as bacterial leaf spot. Then, before you know it, your plant’s leaves have huge holes in them. Well, that is, if the leaves are still attached.
Treating bacterial leaf spot typically requires microbial or biological sprays and products with streptomycin in them, which is an antibiotic. Make sure that while your plant undergoes treatment that you quarantine it from the other houseplants. Many fungal and bacterial diseases can spread!
Learn More Here: Why Are My Indoor Plants Growing Mold?
Look Out for Pests and Remove Them
I’m not saying it’s easy to spot pests, especially the very small ones such as scale. However, you have to try.
Fortunately, getting rid of most critters isn’t very difficult. A bit of alcohol on a cotton swab will send mealybugs packing. You can also combine dish detergent and rubbing alcohol if you want.
Scale also hates alcohol, but depending on how bad the infestation is, that treatment might not be enough. You could have to prune all infected areas of your houseplant too.
Oh, and spider mites also dislike rubbing alcohol, by the way. Pour some alcohol onto a few cotton balls and then coat your plant’s leaves and they’ll be pest-free.
Get into a Good Plant Watering Schedule
If overwatering or underwatering your houseplants is your problem, you’re probably following a set schedule, right? Water every one to two weeks on the dot. Except plants don’t need to be watered on the dot all the time, especially as the seasons change. During the colder months, you can afford to wait a week extra in many cases.
Here’s a much more reliable method. Put a clean finger a few inches deep into the soil. Does the soil feel completely dry or very close to it? It’s time to water your plant. Is the soil still somewhat moist? Plan to water in a few days. Is the soil still very moist? Skip watering for a while, as your plant likely doesn’t need it.
Watch Your Temperature and Humidity
Let me reiterate here. A plant’s humidity and temperature requirements are not suggestions nor preferences, but rules to follow for the plant’s health. It’s okay if it’s 65 degrees in your home and your plant likes temps of around 68 degrees. It’s also fine if your plant needs relative humidity at 50 percent but the humidity in the room measures 52 percent.
Drastically veering away from a plant’s temperature and humidity requirements will cause equally drastic results though, such as leaf shedding. Try your best not to do it!
Fertilize, But Not Too Frequently
Follow the seasons when deciding whether to fertilize your houseplant. In the wintertime, many plants are dormant. Fertilizing them isn’t necessary until they’re ready to enter their active growing season at the start of spring (or thereabouts). You might fertilize once every two weeks or monthly throughout the active growing season.
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