Posted on February 03 2021
One of the most common questions we hear at Parkway is "What's wrong with my plant?" When your plant is struggling it can seem hard to determine the cause. Many common problems may exhibit the same symptoms -- yellow leaves, wilting foliage, leaf drop. With a little investigating you should be able to determine the cause of the problem and get your plant back to good health! Here’s how to identify and treat some of the most common houseplant issues.
Overwatering: Your plant may be suffering from too much of a good thing! If your plant is already overwatered you may notice its leaves are limp, yellow, brown around the edges or falling off all together. The roots of an overwatered plant may become brown and mushy instead of firm and white as they should be. The soil of an overwatered plant will likely remain wet and soggy, the perfect home for pesky fungus gnats.
Avoid over watering by researching your plant’s specific water requirements. You will find that most plants prefer to have the top layer of soil dry out between waterings and that very few plants require constantly moist soil. While it might seem convenient to stick to a weekly watering schedule, it's very important to check whether your plant truly needs to be watered. Lift up your plants every time you water to see how much they weigh, both when the soil is dry and when it is saturated. After a while you will find you can determine whether to water your plant just by briefly picking them up the way we do in a greenhouse! If you are still unsure whether your plant needs water you can push your finger into the soil up to the second knuckle. This will determine if the top layer of soil has dried out. If your finger feels dry then it’s time to water. If your plant has been overwatered simply let it dry out somewhat --not completely-- before watering again.
Overwatering can be caused by other factors too. Make sure your plant has adequate drainage. It should be planted in potting mix with perlite or vermiculite -- not black earth or outdoor garden soil. Make sure the pot is a good fit. Only plant into a pot an inch or two larger than the previous pot. A plant with a small root system and lots of extra soil will not dry out properly and may begin to rot. Avoid pots without drainage holes. Ceramic pots without holes in the bottom are intended as pot covers for plastic pots with drainage. The pot cover will catch any water that drains out, but make sure it does not collect and leave you plant sitting in water.
An overwatered pothos displaying wilting yellow and brown leaves. The whole plant is drooping.
Underwatering: If you’ve forgotten to water recently, your plant may wilt or droop dramatically. Chronic underwatering can lead to yellow or brown leaves that dry up and fall off. Just looking at your plant it may be hard to distinguish between the signs of overwatering and underwatering. Pick up your plant to see how light it is or stick your finger into the soil to feel for moisture. You may even be able to tell at a glance if the soil appears to be very light in colour. Soil that is extremely dry may become hydrophobic and actually repel water. You may have noticed this if you’ve ever watered a very dry plant and had all the water immediately pour out of the bottom of the pot. To fully saturate a dry root ball you can soak the soil, pot and all, in a bucket or sink of room temperature water. Submerge the pot until the air bubbles stop rising and then thoroughly drain any excess water into the sink or a tray. Once the soil is moist it will soak up water more readily and you can begin a regular watering routine.
An underwatered Pedilanthus defoliating. Leaves have turned yellow and brittle and are falling off.
Rootbound: Signs that a plant may be rootbound include wilting, yellow leaves, and stunted or slow growth. By just looking at the plant, these symptoms may seem similar to a watering issue, but it will be easy to diagnose by removing the plant from its container. A rootbound plant will have lots of roots and very little soil. The roots of the plant may circle the base of the container until they push the plant higher up and out of the pot. Constrained roots may press and strain against the side of the container warping plastic or even cracking ceramic and terracotta. Root bound plants will dry out and wilt quickly because there is less soil to hold moisture and more roots to quickly take up any available water.
Repot root bound plants into a container a few inches larger in diameter with some fresh potting soil. For plants that are only slightly root bound you can repot them as-is or gently tease the roots apart and loosen them. You can prune off any circling roots that could strangle the others and prevent them from transferring water and nutrients. Do not cut through any tap roots however, and do not trim off more than a third of the plant's roots. Loosen the roots and allow any of the cut pieces to fall away. Root pruning will stimulate new root growth.
A spider plant starting to become rootbound. Roots are circling the bottom of the container and pushing the plant and soil up, out of its pot.
Too Much Sun: Brighter is not always better, especially for low light houseplants. Light that is too intense can burn leaves, causing brown spots or bleaching foliage. Plants especially prone to burning are wide leaf dracaenas, dieffenbachias, and Chinese evergreens. Move sun sensitive plants out of direct sunlight or further away from grow lights. You can move them to either side or a sunny window, instead of directly in front, or to an east or north facing window instead. Burnt leaves won't heal and can be removed, just avoid removing too many leaves at once. You may need to give your plant time to grow out a bit before removing the damaged leaves.
The fronds of a Majesty palm that has received too much light. Leaves are turning yellow and brown around the edges and feel dry and brittle.
Not Enough Sun: If your plant is lacking sunlight you may notice elongated stems with more distance between each leaf. New leaves may be smaller with stunted growth. Plants will also stretch and lean towards any available light. This is especially evident in succulents, which will become lanky as they grow in search of sunlight. High light plants include cacti and succulents, crotons, sago palms and tropical hibiscus. Try to place these plants in front of west or south facing windows if possible. If you don’t have enough natural light you can add a grow light. Sun loving plants will benefit from grow lights, especially during the long winters when daylight is less intense.
A peperomia kept in low light. Stems are stretching and becoming leggy with more space between each leaf.
With this guide you are now better equipped to identify the signs of a sick plant and how to help them recover. Hopefully this will ease the stress and confusion of the age old question "What's wrong with my plant?"