Green plants with yellow leaves that have fallen off

Why are the leaves falling off my plant?

Article for :All parent plants

You're about to water your favorite Croton, and then the worst happens. It has lost one of its leaves. It's lying at the foot of the pot. Worse still, it's not the first time this has happened this week. Take a deep breath and get ready to take action. We'll explain why your houseplant's leaves are falling off, and what you can do about it.

Leaves fall naturally

In deciduous and semi-evergreen plants, leaf drop is perfectly normal - Photo by Sauletas / Canvas

Falling leaves are a normal phenomenon in plants. Just as we shed hair, plants shed their oldest blades. They grow new ones to replace them. In this way, their foliage always remains plentiful.

You should only start to worry if the plant loses several leaves in a short space of time and doesn't produce any new ones. Is your Maranta Lemon Lime receding faster than Professor Xavier's head? It's time to take action!

But before you panic, remember your SVT lessons. Some varieties have deciduous foliage. In other words, they die in late autumn and winter, only to be reborn in spring (on this side of the planet, at least). This process allows trees to save energy as the days get shorter. There's no need to dig out your high school biology notebooks! You can check your plant's characteristics on the Monstera app. For each species, we tell you whether the foliage is evergreen, semi-evergreen or deciduous.

Your plant loses its leaves after a change

Just like a human being, moving house is traumatic for a green plant

In the store, you fell in love with this bushy, graphic Ficus elastica. Once home, it's a different story. The leaves started to fall off from the very first day.

That's probably to be expected. Houseplants don't really like change. When they're under stress, they tend to lose their leaves. And that's exactly what's happened to your tree. After growing in a greenhouse, with optimal growing and humidity conditions, it was packed, transported and displayed on the shelves of the garden center, in the middle of draughts. You then welcomed it into your home, where the light and humidity are different.

Once your fig tree is used to its new environment, the limbs will stop falling off. In the meantime, there's nothing to do. Just avoid repotting your shrub immediately after purchase, to avoid disturbing it further.

Even a minor event can cause leaves to fall off. Your plant can sometimes become bare after repotting or moving. Some species, such as Ficus and Dracaena, are very sensitive to change. Just move them a few meters and they'll show their displeasure!

Leaf drop due to pest attack

Cleaning leaves is often enough to get rid of parasites - Photo by Valeriia Titarenko /C anva

You haven't moved your Fragrant Dragonwood a centimetre? Perhaps it's been invaded by pests. In this case, leaf drop is not the only symptom. The leaf blades turn yellow, discolored or brown before falling off. Spots may also appear.

Mealybugs, whiteflies, red spiders or mites... The culprits can have many faces. To unmask them, examine the underside of the limbs and the soil. Look for the presence of insects, larvae and eggs. Some pests make your job easier by leaving traces behind. Mealybugs deposit a powdery white down, red spiders spin fine webs and aphids secrete honeydew, a sticky film.

Have you found the signs of an attack? You'll need to treat your plant. The remedy depends on the threat. Red spider mites do not tolerate humidity. Soaking the foliage in lukewarm water is almost always enough to get rid of the problem. Most other insects are not resistant to black soap. Gently wash the leaves with a mixture of warm water and soap to eradicate them. Unless you're dealing with scale insects. You'll probably need a cloth soaked in 90° alcohol.

Don't delay! When it's weakened, your plant is more likely to develop a cryptogamic disease (a fungus). Leaves won't be the only victims. Stems and roots may also die.

After treatment, change your habits to avoid a second invasion. Mist the foliage to prevent the mites from settling in, and air the room every day to renew the air.

Blades turn yellow and die, because you're over-watering your plant

When watering, the substrate should be moist but not flooded

Do you water generously every day of the year, even in winter? Does your houseplant bathe in a soggy substrate? Then the problem is probably over-watering. When plants receive too much water, they can't absorb the excess. The leaves catch the excess, turn yellow and limp, then fall off. Then the roots rot and the plant withers.

To stop the hecatomb, stop watering until the soil is dry. When the situation is critical, repot your plant so that it can immediately benefit from a healthy substrate. Don't hesitate to cut off rotten roots (they are usually soft and brown in color).

Then get back into a proper watering routine, following the advice given on the Monstera app. Don't forget to touch the soil before giving your plant a drink. With the exception of certain varieties, such as dionaea muscipula, most species prefer their soil to dry on the surface before being watered.

Leaves dry up and fall off because you don't water enough

In the sun, your plants will need regular watering - Photo by Pixelshot / Canva

Like excess water, lack of water can also cause leaf blades to fall off. They will then be dry and brown, while the substrate will be hard and compact. You may even notice a gap between the pot and the soil.

Haven't looked after your Chinese coin plant in weeks? Give it a chance to catch up. Water twice, using rainwater at room temperature. Water once to rehydrate the root ball. Wait a few minutes and then water again, so that the plant can absorb the water. Pour water until it runs through the drainage holes at the bottom of the pot.

You can also opt for capillary watering. Fill a container with water at room temperature. Soak the plant in its pot for about 30 minutes. After half an hour, the soil should be moist and the unfortunate plant satiated.

Your plant is losing its leaves because it's cramped up

Don't forget to repot before the roots have taken on the shape of the pot! Photo by Gill Holgate / Flickr

Indoors, plants can lose their leaves because their pot is too small. A quick look is all it takes to confirm the diagnosis: if the roots are escaping from the drainage holes, your plant is cramped! If you have more roots than potting soil, you'll need a larger container.

Re-pot into a container one size larger than the current one. But don't think too big. There's no need to go from a five-centimetre diameter pot to a 50-centimetre tub! You risk drowning your plant during watering. Repotting has a double advantage. As well as giving your protected plant more space, you'll provide it with a nutrient-rich substrate, just as if you'd used fertilizer. After a few days, it will give birth to new leaves.

Blades droop in a dark location

In winter, move your plant closer to a window - Photo by Inga Seliverstova / Pexels

Leaf loss can sometimes be due to a lack of sunlight. There are other signs that the light is too low:

your plant is wilting. Its stems lengthen and grow upwards in search of light;
yellowing foliage;
internodes are larger than before;
new leaves are small and misshapen.

To remedy this, move your plant closer to a bay window. You can also invest in a horticultural light. We don't always realize it, but indoors, light levels are much lower than outdoors. In winter, it's often insufficient just a few meters from a window, even for potted plants that like semi-shade.

Your plant is bare because it's cold..

Don't stick the leaves to the window to avoid a cold snap

Most of the plants we grow indoors are tropical varieties. They appreciate temperatures above 15°. Below this, the leaf blades fall off and the plant may die.

Check the thermometer, then make sure your plant isn 't in a draught and that its leaves aren't stuck against the window. If it is, move it to a more suitable location and wait for it to start growing again.

... Or hot!

During a heatwave, mist your plants to cool them down - Photo by Karolina Grabowska / Pexels

We're not the only ones to suffer during hot weather. The heatwave is also an ordeal for our houseplants. And their foliage can lose a few feathers. In such cases, it's impossible to act on the cause and treat the root of the problem. The best thing to do is to protect your specimens from the heat by keeping them in the shade, misting them and increasing the frequency of watering. How How to take care of your houseplants in hot weather? explained in this article How to take care of your houseplants in hot weather?

But our plants can also get hot in the middle of winter. This happens especially when they're placed near a radiator or when you've turned the thermostat up to maximum. Worried that your Monstera might catch a chill far from its native jungle, so you put it next to the fireplace? Rather than watering it more often, move it to another spot, so that it stops suffocating.

Your plant is balding because it's hungry

Repotting brings new nutrients to the plant for several weeks - Photo by Iryna Khabliuk / Canva

Have you watered correctly? Is the pot the right size and is the thermostat set to 21°? Then your plant may be lacking in nutrients. In your garden, trees and flowers thrive on fertile soil. But in pots and indoors, only substrate and fertilizer provide plants with enough nutrients. If you haven't repotted for a long time and haven't been very diligent about fertilizing, the potting soil is probably exhausted.

A hungry plant can be seen in its foliage. Loss of limbs is not the only sign. Leaves lose their color and turn yellow. You'll need to repot the plant in suitable soil and add fertilizer during the growth phase. If your specimen is too large to be handled, you can make do with resurfacing. Remove at least a third of the soil and replace with fresh, nutrient-rich substrate.

Editor's note: some of these photos have been generated by artificial intelligence. Can you find them? (I promise, it's easier than finding Charlie!)

By Servane Nemetz
on 27-02-2024 at 12h18