When under stress from a drought, over watering, nitrogen shortage, or an excess of phosphorus in the soil, hibiscus leaves become yellow. Tropical hibiscus cultivars respond to a sudden drop in temperature by turning its leaves yellow.
Find out why your hibiscus’ leaves have turned yellow and how to resuscitate it by reading on.
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Drought Stress Causes Hibiscus Leaves to Turn Yellow
Your hibiscus may develop yellow leaves in response to drought stress from dry soil or stress from too much liquid around the roots.
However, if the reason for your hibiscus’ yellow leaves is dry stress rather than overwatering, you may tell the difference if the leaves are visibly withered and curling downward as this is an adaptation to stop water loss.
Conversely, yellow hibiscus leaves brought on by over watering tend to droop and look withered.
Underwatering is not the only reason for drought stress; other factors include:
- too much wind Since hibiscus are native to tropical climes and prefer moderate humidity rather than extreme wind, which dries out the leaves and causes them to turn yellow and shrivel, hibiscus planted in overly windy areas may be more susceptible to drought stress.
- Too soon, soils drain. Hibiscus are used to growing on soils with moisture retention (yet allow excess water to drain away from the roots). If your hibiscus is planted in sandy or stony soil, the soil may drain too quickly for the roots to draw up moisture, generating a hydration deficit and stress-related yellowing of the leaves.
- a lack of watering Established hibiscus that are grown on soil that holds moisture and has a lot of organic matter (compost) rarely need to be watered. However, to keep the leaves from becoming yellow, the soil should be kept constantly moist. As a result, hibiscus often need extra water depending on how quickly your soil dries out.
Revive Yellow Hibiscus Leaves due to Drought Stress
The first thing you should do if your hibiscus is suffering from drought stress is…
- Douse the hibiscus with plenty of water. A generous soak once a week is preferred than frequent, light watering because it ensures that the water penetrates the soil to the depth necessary to reach the roots. Additionally, it promotes root development and growth, which boosts the hibiscus’ resistance to drought.
- Protect the hibiscus from strong gusts that dry out the leaves. High winds cause the air’s humidity to decrease, which is in conflict with the hibiscus’ preferred tropical climate for growth. If you want to protect your potted hibiscus from the wind, think about planting some other shrubs, or relocating it to a spot that is still sunny but protected by a garden fence.
- On help your hibiscus retain moisture, supply nutrients, and enhance soil structure, add a layer of mulch to the soil’s surface. The ability of the soil to hold moisture is increased, reducing the risk of drought, by adding a 1 inch layer of compost, leaf mold, or well-rotted manure to the soil around the hibiscus plant. If your soil dries out too rapidly, apply the mulch once in the spring and once more in the middle of the summer.
- As often as necessary, water the hibiscus to keep the soil moist. Hibiscus grows best in well-draining, continuously moist soil, and when the earth dries out, it turns yellow. In order to avoid drought stress and yellow leaves, watering once a week with a good soak is usually sufficient. However, depending on your climate, you may need to water your hibiscus more frequently in order to keep them looking green.
- To raise the humidity and stop further water loss, spritz the leaves with a spray bottle.
The hibiscus should recover from drought stress with regular watering, protection from winds, and mulch applications.
The yellow foliage should start to become a healthier green color during the course of the following week, and the leaves should appear less withered or curled.
One of the main reasons hibiscus don’t flower is drought stress, but there are other factors as well, which is why I prepared another article with solutions.
Yellow and Drooping Hibiscus Leaves due to Over Watering
Hibiscus leaves can become yellow from both overwatering and underwatering, notably from too much water around the roots, which emphasizes the significance of maintaining the proper moisture balance when cultivating hibiscus.
Because of too much water near the roots, hibiscus plants may develop yellow leaves.
- soils that drain slowly. Heavy clay, excessively compacted, or naturally soggy soils have a tendency to drain too slowly for hibiscus, resulting in excess water pooling around the roots. The conditions for fungal diseases like root rot, which can cause the leaves to turn yellow, are promoted by soggy, saturated soil, which the hibiscus cannot endure. It needs moist, light, friable soil like a loam or compost.
- excess watering Even though hibiscus do benefit from routine watering to keep the soils moist, daily watering can lead to soggy circumstances that make the leaves turn yellow and droop as a symptom of stress.
I advise moving your hibiscus to an area that has been amended with lots of compost to improve soil structure if it was originally planted in particularly slow-draining soil or in a soggy, low-lying area of the garden. Alternatively, you can grow your hibiscus in pots, containers, or raised beds, which have better drainage conditions.
It should be emphasized that it is far simpler to prepare a potting mixture that is properly drained for hibiscus than it is to repair naturally swampy garden soil.
When hibiscus are grown in pots, slow-draining soil conditions can cause the hibiscus to turn yellow if the pots do not have drainage holes in the base.
Potted Hibiscus Leaves Turning Yellow
The same causes that cause hibiscus leaves to become yellow can also cause hibiscus leaves in pots, although there are a few issues specific to pots that might result in yellowing leaves:
- Lack of drainage is the main reason that potted hibiscus become yellow. Your pot must have drainage holes in the bottom else excess water will pool around the hibiscus roots and cause root rot, which will turn the leaves yellow. When hibiscus roots are kept in the same pot for a long period, they may get pot-bound and form a matted lattice that blocks the drainage hole, slowing drainage and depriving the roots of oxygen, which causes the leaves to become yellow.
- Long-term storage of the hibiscus in the same pot can lead the roots to deplete the soil of nutrients, which can cause the leaves to become yellow from nutritional deficiency.
- Yellow leaves on the potted hibiscus may be a response to poor light if it is inside. Although hibiscus may not often make the greatest indoor plants because they like full sun and are sensitive to seasonal changes in temperature and light, if you are growing hibiscus indoors, place it in the room with the most direct sunlight.
- Due to transplant shock, moving the pot from one location to another can cause the leaves to become yellow. Hibiscus can adapt to quite a specific environment (in terms of sunlight, heat, and airflow), therefore if you move the pot from one place to another or move the pot indoors, the stress of the sudden change in environment may cause the hibiscus leaves to turn yellow.
How to Revive Potted Hibiscus with Yellow Leaves
- Occasionally, commercial garden centers will sell hibiscus in attractive pots without drainage holes in the base. As soon as you can, move your hibiscus to a larger or similar-sized pot with drainage holes in the bottom, and reduce watering if the soil seems saturated rather than just moist. Before watering again, let the soil get completely dry to allow your hibiscus a chance to recuperate from water stress. However, root rot is probably the source of the yellow leaves if the roots have been in wet soil for a long time and the plant is tough to salvage.
- For hibiscus that have lived in pots for a while, consider renewing the soil to add extra nutrients. The ideal size to choose is one size larger than the pot you previously used because larger pots can hold more soil and nutrients. The yellow leaves should become green if you treat the soil once a month with a multipurpose fertilizer that is half strength in the spring and summer.
- Always place your hibiscus where it will receive the maximum sunlight. Tropical hibiscus are native, and full sun is ideal for their flowering. The leaves can reverse their yellow hue with enough light.
- If hibiscus are transferred, it may take some time for them to get used to the new environment. The hibiscus should acclimate to its new circumstances and recover from its yellow color as long as it is in full sun, with well-draining yet wet nutrient-rich soil, and protection from severe wind. However, the flower show can be impacted.
(To learn how to revive a dying hibiscus, read my post if your potted hibiscus is in trouble.)
Nutrient Deficient soil Can Causes Hibiscus Leaves to Turn Yellow
Due to their rather intense feeding habits, hibiscus frequently exhibit signs of stress brought on by nutrient deficiencies, the most obvious of which are yellow leaves and a lack of blossoms.
Sandy or stony soils have a tendency to hold onto less nutrients, and soil that hasn’t received any organic matter as a mulch can also be less fertile.
Hibiscus flourish on soil that has had organic matter added to it (such as compost, leaf mold, and well-rotted manure), as this creates the optimal circumstances for nutrients, soil structure, and moisture retention.
Observe these steps if your hibiscus is not growing well, has yellow leaves, and doesn’t have any flowers:
- Apply a 1 inch layer of compost, leaf mold, or well-rotted manure twice a year, in the spring and summer, to the soil surrounding your hibiscus. Through the addition of minerals to the soil and the stimulation of the soil ecology, your hibiscus’ roots will have easier access to nutrients.
- In order to make up for the lack of nutrients in the soil, apply a half strength all-purpose liquid fertilizer to the hibiscus once a month during the spring and summer.
When fertilizing hibiscus, it’s crucial to get the nutrients just right because too much fertilizer can promote the growth of foliage at the expense of flowers and too much phosphorous can also cause the leaves to turn yellow. This highlights the significance of an evenly balanced fertilizer with equal parts Nitrogen, Phosphorous, and Potassium (NPK).
Use granular fertilizer from any trustworthy brand, such miracle-gro, which is readily sold at garden supply stores and on Amazon.
(Read my article on how to enhance hibiscus blooms for more suggestions on how to encourage blossoming.)
Build up of Phosphorous in Soil Turns Hibiscus Leaves Yellow
Hibiscus are rather unique in that they are quite sensitive to high phosphorus soil conditions.
Phosphorus can inhibit hibiscus roots from absorbing other nutrients, resulting in a nutrient deficiency that cannot be remedied by adding more fertilizer.
The plant may die back as a result of this, the leaves may turn yellow, and the hibiscus may not flower in the summer.
Phosphorus buildup in soil is typically the result of overzealous fertilizer application, especially any fertilizer that contains an excessive quantity of phosphorus and is sometimes marketed as a “bloom booster.”
If you think phosphorus is the reason your hibiscus’ leaves are going yellow, reduce the amount of fertilizer you apply, and make sure you water it frequently.
Sending a sample of your soil off for testing is essential to determining for sure whether phosphorus is the issue, and respectable garden retailers and nurseries offer this service.
Although the hibiscus may recover, it is challenging to resuscitate the plant if there is a considerable buildup of phosphorus.
Soil pH Prevents Uptake of Nutrients Causing Yellow Leaves
In soils with a pH of 6-7, which is somewhat acidic, hibiscus thrive. Planting hibiscus in soil that is either too acidic or too alkaline stops the plant from absorbing nutrients from the soil, which causes the leaves to turn yellow with green veins (chlorosis).
Fortunately, most garden soil has a pH in the range of 6-7 because, after fully decomposed, most organic matter has a pH that is somewhat acidic around this range.
But there are environmental factors, such the underlying rock, that can cause soil to be excessively acidic or alkaline.
I advise getting a soil gauge from Amazon or a garden center to determine the pH of your soil if several plants also show yellowing with green veins.
Hibiscus should be grown in pots, containers, or raised beds rather than in garden soil if your soil is far outside of the pH 6-7 range because adjusting the pH of the soil is a difficult process.
If at all possible, move your hibiscus to a pot with multifunctional compost, which will offer the proper pH level for it. Hibiscus cannot survive in excessively acidic or alkaline soils without being moved to a more suitable soil for it to grow in.
Lack of Light Can Cause Yellow Hibiscus Leaves
In full sun, hibiscus, which are indigenous to tropical Asia, flourish and produce their best flowers.
As this is in opposition to the circumstances they like in their native region, too much shade can result in yellowing of the hibiscus leaves as well as poor overall development and fewer blooms.
Put your hibiscus in your garden’s most sunny area. For established hibiscuses, remove any foliage that might be blocking light from reaching the plant or any tree limbs.
To prevent yellow leaves, move potted hibsicus to a sunny patio and place any interior hibsicus in the sunniest window of your home.
The hibiscus should become green again with sufficient sunlight.
Cold Weather Causes Tropical Hibiscus Leaves to Turn Yellow
There are two hibiscus species that gardeners frequently grow.
- Hawaiian hibiscus (Hibiscus rosa-sinensis).
- hibiscus spp. that is hardy.
As you can guess, the hardy species can withstand low temperatures and can survive in a far wider range of conditions than the tropical species.
If the temperature falls sharply from its normal range, the tropical hibiscus leaves may turn yellow. Tropical hibiscus are hardy in USDA zones 9 to 11, although they cannot endure frost.
In order to prevent yellow leaves, it is crucial to grow a hibiscus species that is appropriate for your climate.
After a severe cold shock, tropical hibiscus can also lose their yellow leaves, although they can recover if the weather is moderate.
The tropical hibiscus species struggle to survive outside of tropical regions.
Hardy hibiscus types may withstand frost but need to be planted in full light and, in contrast to tropical variations, flower for a longer period of time.
Insect Pests can Cause Hibiscus Leaves to Turn Yellow
Your hibiscus is more susceptible to insect infestation if it is stressed out owing to poor lighting, unfavorable soil conditions, etc.
Although there are several insects that might harm hibiscus, the spider mite is the most likely culprit for turning the leaves yellow.
Your hibiscus will have tiny yellow spots the size of pins from spider mites, which could result in the leaves falling off and fewer flowers blooming.
However, infestations with spider mites are usually treatable and rarely fatal.
Because spider mites thrive in low-humidity situations, misting the leaves of your hibiscus plant can be an effective deterrent.
Use of an insecticide spray made from neem oil is an efficient remedy for more severe infestations and is non-toxic to other wildlife. To solve the spider mite issue, two or three treatments might be necessary. The hibiscus should recover even though the afflicted yellow leaves frequently fall off.
Sprays with insecticides are sold on Amazon and in garden centers.
Key Takeaways:
- Hibiscus leaves yellow during drought stress, from excessive watering, from too much nitrogen, or from too much phosphorus in the soil. Hibiscus leaves can become yellow due to sudden temperature changes as well as a lack of direct sunlight.
- Hibiscus leaves can turn yellow, shrivel up, and fall off due to drought stress brought on by sandy soils, excessive wind, and underwatering. Increase the frequency of watering, add mulch, and mist-spray the leaves to revive the hibiscus.
- For hibiscus to thrive and maintain their health, they need full sun. Hibiscuses that receive too much shadow lose their leaves, turn yellow, and produce fewer flowers.
- Recreate the conditions that make hibiscus thrive in their natural habitat, including full sun, plenty of moisture, proper drainage, and nutrient-rich soil, to revive hibiscus.
FAQ
Why are my leaves turning yellow on my hibiscus?
Insufficient lighting: If hibiscus leaves are not getting enough light, they may turn yellow. Hibiscus plants are tropical plants, thus they require full sun to some shade to survive. Leaf sunburn from too much direct sunlight can cause tiny white patches to show up on the foliage.
What is the best fertilizer for hibiscus plants?
Plants that grow hibiscus rely mostly on N and K, while using much less P. A fertilizer with an analysis like 10-10-10 will provide a balanced startup feeding at planting time and every year as fresh growth starts in the spring. Select a plant meal with a fertilizer analysis like 12-4-8 or 17-5-24 for routine feeding.
How do you fertilize hibiscus plants?
Tips for Fertilizing Hibiscus Early spring, after the first cycle of blooms has died back, midsummer, fall, or early winter are the best times to apply slow-release fertilizer. Fertilize your lawn every two weeks. To assist fertilizer dissolve and be evenly distributed throughout the root system, water the plant well.
How do I know if my hibiscus is overwatered?
If your hibiscus plants have yellow or occasionally brown leaves, you have overwatered them. A submerged plant will have brittle, yellow leaves, and the growth will bow upward and wither. Regardless of the species, your hibiscus’ leaves will turn yellow if you overwater them.
What do you feed a hibiscus with yellow leaves?
If the leaves on your hibiscus are becoming yellow but not falling off, your plant may be suffering from iron chlorosis and in need of fertilizer, Epsom salts, or a soil amendment.