The oleander (Nerium oleander), also called rose laurel, are large shrubs that reach a height of 6 to 7.5 m and can produce colorful clusters of flowers (pink, yellow, red and white) in summer. These Mediterranean plants are known for both their poisonous properties and their rose-like flowers. They are easy to grow, but if the oleander develops yellow leaves, it is a sign of improper care.
The most common reason for yellow oleander leaves is overwatering and, in the worst cases, leaf spot. You should not over or under water your plant. Yellow leaves are easily prevented with proper soil mix, watering schedule, fertilization and plant hygiene. However, if the yellow leaves are caused by leaf spot, the only solution is to get rid of the plant.
Improper watering
If the oleander develops yellow leaves, it means that there are a number of problems that need to be addressed immediately. Irrigation plays an important role in plant health. Each has its own water needs, which depend on soil, light, temperature and humidity. Improper watering is the most common cause of yellowing of oleander leaves. So pay attention to the following aspects:
- The oleander is considered robust and drought-tolerant, but it likes to be watered abundantly during dry periods.
- Rose laurels do not tolerate overwatering. Therefore, never plant it in soil that does not drain freely.
- Yellow leaves caused by overwatering oleander are easily remedied by changing the watering schedule.
- Underwatering should also be avoided. Otherwise, the root tips die in the dry soil and nutrient levels drop, causing yellow leaves. These root tips will recover once you improve the water supply.
Poor drainage and lack of fertilizers
Poor drainage: Sometimes you water your plant well, but it has inadequate drainage. Either the pot doesn't have proper drainage holes or the soil mix isn't right.
You need to use a balanced potting mix for oleander. It should retain the necessary moisture and drain excess water. Rose laurels can adapt to different types of soils, but:
- Don't use a very porous soil mix because it won't hold moisture properly for the roots.
- Do not use a compacted soil mix as it will retain more water than the plant needs.
In outdoor gardens, when rainwater sits in the soil, the oxygen supply to the roots is cut off. This stresses the plant and it soon begins to develop yellow leaves.
Lack of fertilizers: If the new leaves are still green but the old ones are yellowing, there is a nitrogen deficiency. You should provide your plant with a balanced fertilizer. These yellow leaves will turn green again in 3 to 4 days. Rose laurels should generally be fertilized twice a year (in spring and fall). They do not require heavy fertilization; a slow-release fertilizer 10-10-10 is sufficient.
Fertilizing oleander – what nutrients do you need to supply your plants with? Thefind out here!
Leaf spot is a common disease in oleander
If the oleander has yellow leaves, the cause may be leaf spot. Any variety of the plant is susceptible to this disease.
- Oleander leaf spot is a deadly bacterial disease spread by sharpshooters, spitting beetles or leafhoppers. These pests feed on the plant and introduce the bacterium (Xylella fastidiosa) into the plant stems.
- The bacterium lives in the xylem vessels, where it multiplies and blocks the channels that carry water.
- Leaf spot can occur at any time of year, but most growers have noticed it in late spring and summer.
The first symptom is yellow and droopy leaves. If the bacteria continues to grow, the plant will appear brown and burnt. You cannot cure oleander from this deadly disease. The only solution to this disease is to remove the infected plant. Some experts recommend cutting back the affected parts, but this will only slow the spread of the disease.
Oleander gets yellow leaves from other plants and pests
Other plants:If you plant oleander in a crowded region, the green leaves of this poisonous beauty will turn sickly and yellow. It has an extensive root system that requires a lot of space to grow. Improper spacing between plants can affect the roots and cause yellowing of oleander leaves.
Pests:Oleander may also have yellowed leaves due to pest infestation. These plants are susceptible to sap-sucking pests such as scale insects and mites. Look for oleander mites on the underside of the plant's leaves. They are sucking insects with whitish-brown, flat, oval bodies.
How can you combat spider mites, scale insects, etc. using simple home remedies? Theyou can read here!
Useful tips to avoid yellow leaves
- Check the soil regularly. If it stays too wet, consider reducing watering or improving drainage.
- When watering oleander outdoors, use a trickle irrigation system as overhead watering will make the leaves unnecessarily wet.
- If the area around the central vein turns yellow, your plant is under stress due to lack of water.
- Watering your rose laurel heavily after a dry period can also result in yellow leaves. I would recommend watering regularly, but with little water.
