The dilemma begins with individual, yellowed leaves. If these first signs of a problem with the oleander are underestimated, over time all the leaves will turn yellow and fall off. Since various causes can cause this damage, there is no patent recipe available as an answer to the question. By putting all the basic conditions of cultivation to the test, the real cause of yellow leaves on rose laurel will ultimately emerge. Find out what to do to get your ailing oleander back on track here.
Cause: drought stress
What to do: pour properly
The water requirement of an oleander cannot be rated highly enough. The magnificent flowering wood turns out to be so thirsty, especially in summer, that the coaster should be permanently filled with water. Your rose laurel reacts to drought stress with yellow leaves within a short time. When all the nutrients it contains have been transferred to the roots, the shrub sheds the leaves to reduce the degree of evaporation. Instead of watering an oleander according to a strict schedule, please adjust the water supply immediately as follows:
- Dip a dried out root ball in water until no more air bubbles rise
- During the warm season, place the bucket in a tall saucer filled with water
- Always water the substrate when it is dry
- Refill evaporated water in the saucer promptly
- Never water the rose laurel under direct sun
Even though the oleander comes from the Mediterranean, it requires calcareous water. Therefore, please only use normal tap water at normal room temperature. Daily gardening practice has shown that soft rainwater causes a lack of lime, whereupon the leaves turn yellow.
Tip: An oleander can safely be poured with water from the rain barrel if the resulting lack of lime is compensated. For this purpose, sprinkle garden lime or algae lime on the ground every six months and water.
Cause: lack of nutrients
What you have to do: fertilize in a balanced way
If the yellow leaves in the oleander spread evenly, this indicates a lack of nutrients. This is especially true if the damage occurs in the middle of the summer growth and flowering period. Please keep in mind that a rose laurel
is one of the heavily consuming plants. You should therefore check the nutrient balance in order to adjust it to these intervals if necessary:- Fertilize weekly from May to August
- Give an NPK fertilizer at 15-10-15 or higher
- Ideally add to the irrigation water as a liquid fertilizer
- Pour clear water before and after
The rest of the year you cut off the nutrient intake. Outside of the flowering period, your oleander does not need any additional fertilizer. On the contrary, it could lead to over-fertilization, which in turn causes the leaves to yellow and fall off.
Cause: aging
What to do: trim back or taper
As an evergreen flowering shrub, an oleander does not shed its foliage in autumn and winter. However, this characteristic does not mean that the individual leaves live forever. In fact, an oleander leaf lives around 2 years old. At the end of its life it releases its remaining nutrients to the shrub, turns yellow and falls to the ground. This natural process leads to aging from below in the long run. The young leaves standing above no longer let enough light through, so that fallen leaves are not renewed at the base. If you can identify this process as the cause, cutting back will correct the problem. How to do it right:
- Thoroughly thin out an oleander at least once a year
- Cut off dead wood and shoots that are too close together at the base
- Shorten branches that are too long by up to three thirds
- Make the cut just above a leaf base
If the annual shape and maintenance pruning has been neglected for several years, so many yellow leaves have fallen off that the baldness is well advanced. Thanks to a robust cut tolerance, you can rejuvenate your oleander. The pruning can be done up to a shoot height of 10 cm. The shrub sprouts quickly from the old wood so that it regenerates within 1 to 2 years.
Tip: The high levels of toxins in the oleander require long-sleeved clothing and protective gloves to be worn. The toxic clippings should not be disposed of on the compost, but in the household waste.
Cause: Wrong location
What to do: Relocate immediately
As a Mediterranean
Oleander plant loves the sun and is not hardy. This has the advantage that the opulent flowering shrub can cause a sensation on balconies and patios from spring to autumn. If it is not comfortable with the assigned location, the rose laurel will respond with yellow leaves that will sooner or later fall off. Since the frost-sensitive plant depends on cultivation in the tub, you can optimize the location if in doubt. The damage pattern regenerates quickly under the following conditions:- Relocate to a sunny, warm location
- Protection from wind and rain is recommended
- Gladly on the south side of the house
Leaves with yellow spots often develop immediately after clearing them out. This damage occurs when an oleander is seamlessly placed in full sunshine and suffers from sunburn. As a sure sign of this cause, the yellow spots are not spreading any further. By allowing a rose laurel to acclimate itself in a partially shaded location for 1 to 2 weeks, you can effectively prevent such leaf damage. Affected leaves should not be removed as the remaining green tissue continues to take part in vital photosynthesis.
Cause: Improper winter storage
What has to be done: Hibernate in a species-appropriate manner
An oleander is robust enough to stay outdoors in mild winter locations. This applies, for example, to the Rhineland or the wine-growing regions. As long as the thermometer does not drop below -5 degrees Celsius at night, no special precautions are necessary. Where it gets rough in winter, on the other hand, there is a risk of yellowing and leaf shedding if a rose laurel is not properly guided through the cold season. Therefore, question the wintering in order to create the following ideal conditions:
- Put the oleander in a light-flooded winter quarter
- Gladly in the unheated winter garden, the bright staircase or the sunny garage
- Compensate for a lack of light with plant lamps
- Temperatures between 0 and 10 degrees Celsius are ideal
- The darker the room, the lower the temperatures should be
- Reduced watering without letting the root ball dry out
- Do not give fertilizer
Lack of light, too low and too high temperatures cause your rose laurel to pull in and shed the leaves. After optimizing the conditions, the shrub will recover within the following weeks and months. If there is no better winter accommodation available, this is no cause for concern. At the latest when you clear out your oleander in spring, new, lush green leaves will sprout.
Cause: root pressure
What to do: repot
At a young age, your oleander will grow so rapidly that the tub will be completely rooted within a year. If the ornamental shrub is not repotted in a larger container with fresh soil, the resulting pressure from the roots affects the supply of the leaves. These turn yellow and fall off, although regular watering and fertilization are used. If the root strands grow out of the opening in the ground and push themselves up through the substrate, repot the narrowed rose laurel as follows:
- The best time is in early spring, just before clearing out
- The new bucket is no more than 5 to 10 cm in diameter larger
- Fill the vessel up to a third with a mix of bucket earth, clay and sand
- Tie the shoots together with a string and pot the oleander
- Clean off all the yellow leaves
- Shake off the used soil or rinse it off
- Cut out the softened roots
If you want to use the previous pot again, you can shorten the roots by 2 to 3 cm. Plant the rose laurel in such a way that the previous depth is maintained. Pour generously. So that the stressed shrub can recover, it stays in the partially shaded, sheltered place for 8 to 10 days.
Cause: oleander cancer
What to do: fight naturally
If you were able to rule out all of the causes mentioned so far, there is reason to assume that the plant suffers from oleander cancer. In addition to the yellow, falling leaves, the shoots are also covered with gray-brown to black growths. Above these growths, the twig dies, causing the yellowing and leaf shedding. Oleander cancer is triggered by a bacterium. Experts believe that all European oleanders are infected with it. Whether the disease actually breaks out depends on the constitution and resistance of the respective plant. This is to be done now:
- Cut back all infected shoots into healthy wood
- Dispose of the infected clippings in the household waste
- From now on, pay attention to optimal care in order to increase the resistance
Scientific observations have shown that a vital and vigorous oleander can certainly live with the infection. The more vigorous the shrub, the quicker it will close the gaps that have arisen with fresh shoots and young leaves.
Tip: The main carriers of cancer-causing bacteria are contaminated cutting tools. Before cutting your oleander, scissors or knives should be disinfected with high percentage alcohol.
Cause: lice of all kinds
What to do: fight with home remedies
The lush, evergreen leaves are a favorite target of all kinds of lice. Aphids, scale insects, mealybugs and mealybugs have no qualms about settling on the leaves. The pests prick the tissue with their mouthparts and extract the sap from the leaves. As a visible symptom, the leaves change color, often curl up and fall off. How to fight the plague with home remedies:
- Quarantine the affected oleander
- Remove all pest-infested leaves
- Rinse the bush - if possible upside down -
- Wipe the leaves and shoots with an alcohol-soaked cloth
As a natural control agent, the classic soft soap solution puts an end to infamous lice. Put 1 liter of lime-free water and 1 tablespoon each of soft soap and alcohol in a spray bottle. With this spray you treat the upper and lower sides of the leaves every 2 to 3 days in order to destroy even the last lice.
Conclusion
If your oleander has yellow leaves and these are falling off, a variety of triggers can cause the damage. Therefore, carefully analyze the entire cultivation. The spectrum of possible causes extends from drought stress, nutrient deficiency and aging a wrong location and improper wintering up to root pressure, oleander cancer and Pests. Once you have found the real cause, your afflicted oleander will recover again as a result of adequate measures. These instructions not only show possible causes, but also explain exactly what to do.
