When your plant looks unwell, it’s trying to tell you something. But figuring out precisely what it’s saying can be a challenge. Is it thirsty or drowning? Starving for light or getting scorched? This guide serves as your starting point for diagnosing common houseplant issues.
Think of yourself as a plant detective. Below are the most common symptoms or “clues” your plant will give you. Find the clue that matches your plant’s issue to uncover the most likely culprits and find a path to treatment.
Before You Begin: The “Big Three” Questions
Always start by asking these three questions, as the answer often points directly to the problem:
- Watering: When was the last time you watered it? Did you check the soil first? Does the pot feel very light (dry) or very heavy (wet)?
- Light: How much light does this spot really get? Has the light changed recently (e.g., seasons changing)?
- Pests: Have you looked closely, really closely, under the leaves and on the stems for any tiny signs of life?
Now, let’s get to the clues.
Clue #1: My Plant’s Leaves are Turning Yellow
Yellowing leaves (a process called chlorosis) are the most common symptom houseplants show. The location of the yellowing is your biggest clue.
- If the lower leaves are turning yellow and the soil is damp…
- Likely Culprit: Overwatering. This is the #1 cause of yellowing leaves. The roots are suffocating and can’t deliver nutrients, causing older leaves to be sacrificed first.
- Next Step: Visit our Ultimate Guide to Watering Your Houseplants to learn about proper watering techniques and how to check for Root Rot.
- If leaves are turning yellow all over the plant and growth seems stunted…
- Likely Culprit: Nutrient Deficiency. The soil may be old and depleted of essential nutrients, such as nitrogen.
- Next Step: Read our Guide to Fertilizing Houseplants to learn how and when to feed your plants.
- If there are yellow spots or strange yellow patterns…
- Likely Culprit: This could be a pest or a disease. A yellow “halo” around a brown spot often points to a fungal issue.
- Next Step: Compare the spots to the images in our Plant Disease Library and check for insects with our Visual Guide to Common Houseplant Pests.
Clue #2: My Plant has Brown, Crispy Spots or Edges
Brown, dry spots usually indicate a lack of moisture somewhere in the plant’s environment.
- If just the very tips or edges of the leaves are brown and crispy…
- Likely Culprit: Low Humidity. The air is too dry, causing the most sensitive parts of the leaf (the tips) to dry out. This is extremely common in homes during winter.
- Next Step: Learn easy ways to raise the moisture in our Guide to Houseplant Humidity.
- If there are large, dry, brown patches, sometimes in the middle of the leaf…
- Likely Culprit: Underwatering or Sunburn. If the soil is bone dry, the plant is thirsty. If the patches are on the parts of the plant getting the most intense sun, it’s likely sunburn.
- Next Step: Review the proper watering techniques outlined in our Watering Guide and assess your lighting situation using our Guide to Understanding Light.
- If the brown spots are dark, mushy, or have a yellow halo…
- Likely Culprit: Fungal or Bacterial Disease. Dryness is not the issue here; a pathogen is.
- Next Step: This is a job for the Plant Disease Library.
Clue #3: My Plant is Drooping or Wilting
A wilting plant looks incredibly sad, but it’s giving you a very clear signal.
- If the plant is wilting AND the soil is bone dry…
- Likely Culprit: Underwatering. The plant simply doesn’t have enough water in its cells to support itself.
- Next Step: This is an easy fix! Give it a thorough drink. Learn the best way to do this in our watering guides.
- If the plant is wilting BUT the soil is damp or wet…
- Likely Culprit: Overwatering and root rot. This is a critical situation. The roots are rotting and can no longer absorb water, so the plant is wilting from thirst even though it’s sitting in water.
- Next Step: Immediately go to our step-by-step guide for treating root rot. Do not give it more water!
Clue #4: My Plant’s Growth is Weak or Strange
Changes in growth patterns are a slow-burn symptom that tells you about long-term conditions.
- If the plant is stretching out with long gaps between the leaves (“Leggy”)…
- Likely Culprit: Not Enough Light. The plant is desperately stretching to find a better light source. This is called etiolation.
- Next Step: It’s time to find a brighter spot.
- If new leaves are coming in much smaller than older ones…
- Likely Culprit: Insufficient Light or Nutrients. The plant lacks sufficient energy (from light) or building blocks (from fertilizer) to produce fully developed leaves.
- Next Step: Assess both your lighting using the light guide and your feeding schedule using the fertilizer guide.
- If a variegated plant (with white or pink patches) is putting out all-green leaves…
- Likely Culprit: Not Enough Light. The plant is trying to maximize its food production by creating more chlorophyll (the green part). It’s reverting to its stronger, non-variegated form to survive.
- Next Step: Move it to a brighter location. Our light guide explains the needs of variegated plants.
Still unsure what’s wrong? Sometimes the best diagnostic tool is a second pair of eyes. Post photos and your questions in our community forum for help from our network of passionate plant owners.
