Indoor Plant: Troubleshooting Guide
What is wrong with my houseplant? This is probably the most common concern in indoor gardening. One plant starts to look a bit worse than it did when you bought it, and panic ensues. Gardeners, either by humility or plant hypochondria, tend to blame themselves. However, there are many culprits in ill plant health – gardeners being only one of them. Let’s look at some indoor plant troubleshooting.
Remember, your home environment is wildly different to the greenhouse your new plant grew up in. In a nursery, plants are grown under optimal conditions for rapid growth – high light and humidity, untreated water, good air flow and comfortable temperatures. Their structure and shape are constantly monitored to ensure they look perfect for resale. Leaving that environment, a plant is faced with lower light, chemically treated water, stale air and lower humidity.
Plants may react to a change in environment by losing shape or dropping leaves as they become accustomed to the new conditions. This doesn’t mean a plant is unhealthy. Like any living thing, it just needs time to adjust. It’s also unrealistic to assume a plant will always look as beautiful as it did on day one. Just take a stroll around any garden and you will see that perfect plants are an unrealistic expectation. Not matching the sale-ready image of the plants in a nursery is not always a cause for alarm. Plants in your home environment match those out in the wild more closely – one broken stem or a lopsided leaf doesn’t necessarily indicate a dying plant.
That being said, there are some common indicators that a plant is in distress. This is a part of plant communication: reading the signs your plant is giving you and knowing how to react. These common problems can have a range of causes. Go through this list, identify the most probable cause and attempt to rectify it, following a process of elimination until you pinpoint the issue. Indoor plant troubleshooting can seem difficult at first, but with practice – like any language – it becomes second nature.
Problem #1: Yellowing leaves
Yellowing leaves are a common houseplant problem. This can also be difficult to solve because it has many possible causes. The first, and one that is no cause for concern, is the plant’s age. As plants grow and age, their lower leaves will turn yellow and drop off. If you’ve had your plant for a long time, and only a few leaves are affected, you’re in the clear. Most often, the cause of yellow leaves is related to moisture – either too little or too much.
To diagnose, examine the soil: if it is extremely wet or extremely dry, you have a potential answer. Remove the yellowing leaves, adjust your watering and the plant should be okay. In the absence of soil issues (and the presence of confidence in your watering abilities), the next culprit is air. All plants love good air flow, but tropical plants are not accustomed to cold air from an air conditioner or window and respond by dropping leaves. Move the plant away from the area and keep an eye on it to see if the problem subsides. If it doesn’t, the problem could be a lack of light. This is usually easier to identify as one side of the plant – the side furthest from the light – will show yellowing leaves first.
If the yellowing has a pattern, or begins at the top of the plant, a nutrient imbalance is usually the cause. While it may be a deficiency, most often it is the result of over-fertilisation. Too much fertiliser causes the leaves to burn, resulting in the patchy yellow colour.
Blotchy yellow spots could have another insidious cause – fungal infection. Be sure to confirm the infection by testing for all the previous causes. Fungal infections are difficult to eradicate and can spread to your other plants. As tough as it may be, best practise is to discard the plant to protect the others.
Problem #2: Brown leaves
When performing indoor plant troubleshooting another frequent problem is brown, crunchy leaf tips. Like yellow leaves, watering could be the problem – more specifically, under watering. If the leaves wilt before they turn brown, underwatering is the cause. Adjust your watering, cut off the brown tips, and the problem should resolve itself. Extreme temperatures are another cause.
Depending on the plant and what temperatures it can withstand, temperatures that are too high or too low can cause the leaves to brown and fall off. High humidity plants may brown at the leaf tips in extremely low humidity environments (which can be adjusted using the methods discussed previously). Leaf scorch is a problem not common indoors, but if your plant is receiving direct sunlight for a long portion of the day and doesn’t have enough air circulation, its leaves may burn and turn brown.
Problem #3: Weak growth
Whether it’s stretching taller or putting out new leaves, there should always be signs of healthy growth in plants during spring. The absence of those signs can be a sign of weak or stagnant growth, caused by problems above or below the soil. Above the soil, light is the main source of plant growth. It follows that a lack of light results in a lack of growth (as the plant doesn’t have enough energy to grow and produce new leaves). Move the plant to a sunnier spot and give it some time to adjust. Below the soil, overwatering could be the problem. One accidental overwatering is unlikely to cause trouble, but consistent overwatering will result in root rot. As the roots die, they are unable to transport nutrients and water around the plant, so it is unable to grow. Some plants can be salvaged with a repotting, but severe root rot is usually fatal.
Alternatively, if your plant has been in the same pot for a significant amount of time and is no longer growing, it may be time for a repotting. As the roots outgrow the pot, they cannot draw up nutrients as the roots are tangled. Excessive roots will also deplete soil nutrients faster. If changing patterns in light and watering do not fix the growth, repot your plant.
Problem #4: Drooping leaves
Wilting, unlike the other issues, has a main cause – watering. Water too little and there is not enough water in the plant cells, causing the leaves to droop. Water too much and the roots are suffocated, unable to transport water to the plant cells, causing the leaves to droop. A look at the soil should tell you which side your plant falls on so you can adjust your watering levels.
Problem #5: Dropping leaves
Watching your prized houseplant shed its leaves can be a stressful experience, especially when you don’t know what the cause is. The most common culprits are a change in environment or age, and rectifying this requires some patience to allow the plant to go through its natural processes. Besides these two reasons, almost any environmental issue can cause a plant’s leaves to drop – incorrect watering, extreme temperatures, lack of light, injury from being knocked, nutrient deficiency – the list goes on. The worst solution is to panic and dramatically adjust your care routine; you could compound the problem and do more damage.
Start your indoor plant troubleshooting by having a one-on-one with your houseplant. Assess the soil, your watering habits, the light levels and your home’s humidity. Begin with the condition you believe is the least in tune with the plant’s needs and adjust it. If that does not solve the problem in a couple of weeks, work your way down the list until you find the issue.
Problem #6: Curling leaves
Depending on the structure of the plant, some leaves may not wilt but will curl at the edges. Like wilting, under-watering could be the problem, and a quick drench will bring the leaves back to health. If curled leaves have signs of scorching, too much sunlight could be the problem. Another possible cause of leaf curl is pests: some pests suck out sap or stick to leaves, causing the deformity. Take a closer look at the leaves for small bugs or eggs, and you may have your answer.
Problem #7: Few flowers
Flowering indoor plants are rare for a simple reason – there is not enough light for the flowers to grow. Those with a flowering indoor plant (or those who are trying to grow an outdoor plant indoors) may struggle to get the plant to flower unless they consistently have enough light. If your plant is not putting out any flowers, light is usually the cause. On the other hand, if the plant is growing lots of leaves but no flowers, the soil contains too much nitrogen. As we discussed in Chapter 1, nitrogen is for foliage while phosphorus aids in the growth of flowers. An abundance of nitrogen will prioritise leaf growth, with few nutrients to aid in flower production. Fertilise the plant with a phosphorus-rich fertiliser and you should have flowers in no time.
Problem #8: Stretching/ growth on one side
Although plants may never look as good as they did in the nursery, there are some structural issues caused by the plant’s environment that can be avoided or resolved. A plant with excessive growth on one side needs more distributed light, which can be achieved by moving the plant or simply rotating it regularly. Stretching is another common structural problem indicating the plant is not getting enough light.
When a plant is light stressed, is will start growing toward the nearest light source, causing it to lean to one side. The leaves will also spread further apart, resulting in a lopsided plant with sporadic leaves. This is a widespread problem in indoor succulents – dense collections of leaves will begin to stretch out and deform to get more light. Change the conditions, provide some support, and the growth should return to normal.
Indoor plant troubleshooting can be a stressful task, especially for new plant parents. Don’t panic (very few problems are solved by panicking, anyway). You’ll know which of the causes is most likely by assessing your home environment and gaps in your care routine. Don’t worry if you don’t get it right the first time. Good troubleshooting takes practise and an intuition that can only be learned by getting stuck in. Regular doctors need years and years of study to be successful – becoming a plant doctor and getting your indoor plant troubleshooting won’t happen overnight.