Hibiscus plants light up the garden with their large flowers and beautiful foliage. However, sometimes hibiscus leaves lose their green glow and begin to fade. We’ll explore some common reasons why your hibiscus leaves may be turning yellow and ways to remedy the discoloration.
Reasons Why Hibiscus Leaves Turn Yellow
If you notice that your hibiscus leaves are turning yellow, the first step is to pinpoint the cause of the discoloration. Once you’ve nailed down the reason, you can attempt to fix the problem.
Here are some common reasons why your hibiscus leaves may be turning yellow.
Too Much Water
Overwatering is one of the most common reasons hibiscus leaves turn yellow. While hibiscus plants like their soil moist, they do not like sitting in wet or saturated soil.
If you water your hibiscus too much or plant them in poorly-draining soil, the roots may not be able to properly exchange air and nutrients. Wet soils will also increase the chances that hibiscus roots develop root rot.
Root rot refers to multiple fungal pathogens that can cause roots to deteriorate. When this happens, the roots cannot take up water or nutrients nor complete gas exchange, all of which can lead to yellow leaves.
If your soil seems constantly wet, you can decrease how much you water your plants. While temperature, sunlight, and soil type will impact how often you need to water, you should water when the top two inches of soil is dry to the touch.
Not Enough Light
Most hibiscus plants require at least six hours of daily direct light to thrive. If your hibiscus plant is growing in full or partial shade, it may not be receiving the light it needs.
Hibiscus, like all plants, requires light to complete photosynthesis. This is the process plants use to convert sunlight, water, and carbon dioxide into carbohydrates, oxygen, and water.
Without enough light, hibiscus plants cannot complete photosynthesis properly. This can lead to a lack of carbohydrates and the inability to complete essential plant processes.
Yellow leaves are one symptom that may indicate your plant doesn’t have the energy it needs to thrive. If you suspect your hibiscus isn’t receiving enough light, try moving it to a brighter location.
Cold Temperatures
When it comes to the proper temperature, you’ll need to pay close attention to the type of hibiscus you’re growing. There are two main types of hibiscus: tropical hibiscus and hardy hibiscus.
Tropical hibiscus is native to hot areas where temperatures rarely dip below 50°F. Therefore, they may begin to experience decreases in health (such as yellowing leaves) if temperatures consistently fall below 50°F.
If you are expecting a cold snap, you can move potted tropical hibiscus indoors or cover outdoor plants with row-cover or a blanket. Just make sure to remove the covering when the sun comes out and temperatures warm.
Hardy hibiscus, on the other hand, can survive temperatures below low 0°F. However, this type of hibiscus will lose its leaves when colder weather arrives.
Lack of Nutrients
Like all plants, hibiscus needs a variety of nutrients to thrive.
Yellow leaves can indicate that hibiscus plants are deficient in one or more nutrients. One way to determine what nutrient they may lack is by looking at which leaves are yellow.
If older leaves are yellow but new leaves are green, the plant lacks a mobile nutrient like nitrogen, phosphorus, or magnesium. And if the new leaves are yellow, but the old growth is green, the plants may be lacking an immobile nutrient like sulfur, iron, or manganese.
You can remedy a lack of nutrients by applying a light dose of fertilizer such as Espoma Organic Flower-Tone.
Improper Soil pH
While most people concentrate on the presence of nutrients in the soil, it’s important to remember that soil pH also has a big impact on nutrient availability.
If the pH is too high or too low, hibiscus plants will not be able to take up certain nutrients. You should aim to keep the pH slightly acidic to neutral, between 6.0 and 7.0.
You can lower the soil pH by adding sulfur and raise the soil pH by adding lime. However, be aware that it can take a few months for these materials to change the pH.
Frequently Asked Questions:
Will Yellow Hibiscus Leaves Turn Green?
Hibiscus leaves are unlikely to change back to green once they’ve turned yellow. However, new green leaves can still emerge.
Does Overwatering Hibiscus Cause Yellow Leaves?
Yes, overwatering hibiscus plants can cause the leaves to turn yellow. Keep the soil moist but not wet.
Yellowing Hibiscus Leaves: Wrapping Up
Numerous factors can cause hibiscus leaves to turn yellow, including cold temperatures, overwatering, and lack of light. Do your best to determine the issue facing your plant to remedy the problem.
For more, see our in-depth guide to hibiscus flower meaning and symbolism.
Briana holds a B.S. in Plant Sciences from Penn State University. She manages a small market garden where she grows vegetables and herbs. She also enjoys growing flowers and houseplants at home.
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