What to Do When Hibiscus Leaves Turn Yellow and Drop? Causes and Solutions

"That lovely eldest daughter of the Jiang family, her virtuous name never forgotten." The hibiscus comes in rich colors, and through the ages writers and scholars have described it countless times; among these, my favorite is “The wind and dew blow cold, the sky at dusk. In the courtyard stands a hibiscus, blooming and falling in a single morning.” So when growing hibiscus you may also encounter the problem of leaves turning yellow. How should it be solved?

What to Do When Hibiscus Leaves Turn Yellow

1. Pay attention to watering. Hibiscus likes a warm, humid climate and environment; during the growing season it is enough to keep the soil moist. If it is too dry or too much water is given, this phenomenon will occur. Usually control the amount of watering, and just do a good job of drainage on rainy days.

2. Pay attention to fertilizing. For hibiscus, phosphorus and potassium fertilizers are the main fertilizers, supplemented by nitrogen fertilizer for reasonable topdressing. If too much fertilizer is applied it will burn the root system and cause the leaves to turn yellow and drop.

3. Prevent pests and diseases. Leaf blight is one of the causes of hibiscus leaves turning yellow and withering. Its characteristic is that it produces many small black disease spots on the back of the leaves. Using sprays such as mancozeb can restore the leaves to normal. Aphids are one of the more common insect pests of hibiscus; they suck the leaf sap, and sucking too much will cause the leaves to gradually turn yellow and wither. If that is the case, pesticides must be sprayed promptly for control.

In addition, repotting during the flowering period can also cause the plant's leaves to turn yellow. This is because repotting at this time will cause a certain amount of damage to the hibiscus root system. Once the root system is damaged, its flowers and leaves will also suffer a certain amount of damage, causing the leaves to turn yellow and fall off.

Causes of Hibiscus Leaf Drop and Solutions

1. Improper watering

Hibiscus does not have high water requirements; during the growing period it is enough to keep it moist and not dry. But if too little water is given, or if on rainy days drainage is not paid attention to and there is too much water, it will cause hibiscus leaves to turn yellow and drop. So even though hibiscus is not strict about water requirements, we still need to pay attention to maintaining the water supply.

2. Unreasonable fertilizing

Many people hope hibiscus will grow vigorously and bloom more, so they pay attention to fertilizing it. In fact, for hibiscus it is enough to mainly use phosphorus and potassium fertilizers, supplemented by reasonable topdressing with nitrogen fertilizer. If too much or too concentrated fertilizer is applied, it instead causes trouble; the most obvious is burning the root system, causing leaves to turn yellow and fall off. So if yellowing and dropping of hibiscus leaves occurs after fertilizing, pay attention to checking whether the problem is that the fertilizer was too concentrated.

3. Failure to spray and kill aphids on time

Aphids are a very common insect pest and are also dangerous to the growth of hibiscus. Aphids suck a lot of leaf sap; once the leaf sap on the leaf surface is sucked dry, the leaves slowly turn yellow. So when leaves turn yellow and drop, you should also check whether aphids are causing trouble. If so, you can spray a 1000-fold dilution of 40% omethoate emulsifiable concentrate for treatment.

4. Failure to prevent and control leaf blight

The occurrence of leaf blight can also cause hibiscus leaves to turn yellow and wither. For this, you need to check whether there are small black disease spots on the back. If it is leaf blight, you can use 80% thiophanate-methyl or mancozeb, spraying once every 5 days, until the leaves recover!

5. Repotting during the flowering period

Repotting is also very necessary to promote the healthy growth of hibiscus, but the timing must be grasped. Repotting is strictly forbidden during the hibiscus flowering period, because repotting will more or less damage the root system. Once the roots below are damaged, the flowers and leaves above will certainly be affected, and yellowing and dropping of leaves will easily appear.

How to Select Hibiscus Flowers

Mostly wrinkled into clumps or irregular shapes, 2-4cm long, 1-2cm wide, the whole body covered with hairs. The calyx is bell-shaped, yellow-green or yellow, with 5 lobes at the tip, the lobes triangular; outside the calyx tube there are 6-7 bracts, linear; the lower part of the calyx tube often bears a pedicel, 3-7mm long; the surface of the calyx, bracts and pedicel is densely covered with fine hairs and stellate hairs; petals 5 or double, yellow-white to yellow-brown, the base connate with the stamens, and densely bearing long white soft hairs; stamens numerous, the lower part of the filaments united into a tube, surrounding the style; the stigma is 5-parted, extending out of the filament tube. Texture light and brittle, odor slightly fragrant, taste bland.

How Hibiscus Propagates

1. Cutting propagation

Cuttings are relatively easy to root; some even use long branches, but the depth inserted into the soil must reach at least 20cm, otherwise they easily lodge, or after sprouting suffer drought damage due to shallow roots; generally cuttings are taken in spring, and in the same year's summer and autumn seasons they can bloom.

2. Cutting time and method

After the local temperature steadily passes 15°C, select strong 1-2 year old branches that have not yet sprouted (if the hibiscus branches have sprouted and grown leaves when cutting, the newly grown leaves should be removed), cut them into small sections 15-20cm long. When cutting, prepare a small stick, poke small holes in the seedbed according to the plant and row spacing, then insert the hibiscus branches, firm the soil, with an insertion depth of 10-15cm, that is, an insertion depth reaching 2/3 of the cutting is suitable, and water thoroughly immediately after insertion. No base fertilizer needs to be applied when cutting. For indoor potted cutting, select strong 1-2 year old branches about 10cm long, remove the lower leaves, cut the upper leaves in half, and insert them into a small pot with coarse sand as the substrate, cover with a plastic cover to retain moisture, maintain relatively high humidity, and under conditions of 18-25°C they can root in about 20 days.

Cutting density

The density for raising seedlings and transplanting differs from that for direct cutting. ① For the seedling-raising and transplanting method, for ease of operation, make beds 100cm wide and 25cm high, and insert according to a plant and row spacing of 15×30cm; ② For the direct cutting method, single-row insertion can be done at a plant and row spacing of 50×60cm, or bed cutting can be used, making beds 60cm wide and 25cm high, and inserting in double rows on the bed in a “pin” shape, with a plant spacing of 60cm. In cultivation, one can use the characteristic that cutting seedlings bloom in the same year, cut according to the seedling-raising and transplanting density, and after the 2nd year, before sprouting each spring, thin the seedlings according to a certain density, ensuring that the hibiscus has enough nutritional space for growth that year, so as to increase fresh flower yield.

3. Division propagation

Before sprouting in early spring, dig up vigorous adult clumps, take 3 main branches as 1 clump, and plant them at a plant and row spacing of 50×60cm.

The hibiscus flower shape is elegant, the branches and leaves are luxuriant, and the flowering period is relatively long. When it blooms, the whole tree is full of purple, red and white flowers, dazzling and charming. The flower shape of the hibiscus matches its name especially well, gentle and grand, bright and moving, and it also tells us that in the bygone years of the hibiscus, the years are long; may you be well.