Oleanders – care, pruning, propagation and wintering

Germany is in zones 6 to 7 (minus 23.3 to minus 12.3 degrees) with isolated areas in zone 8 (not colder than minus 6.7 degrees). The oleander native to the Mediterranean and the Orient is used to the warmth of USDA zones 10 (without frost) to a maximum of 8. That is why oleanders and German gardens rarely go together. However, it also depends on the selected variety among the approximately 160 oleanders. There are indeed oleanders that can survive the winter in German gardens with winter protection. The varieties “Nerium villa romaine”, “Nerium atlas”, “Nerium italia” and “Nerium cavalaire” have survived in field tests down to minus 10 degrees with almost no damage. “Nerium Provence” is said to be almost similarly frost resistant. Even when the temperatures drop even lower, the rose laurels only gradually give up.

Oleanders that were exposed to temperatures below minus 20 degrees and had died off completely in the upper area sprouted again in the spring. If you get the right type of oleander in a mild region, you can plant the oleander in a sunny spot in the garden.

Then you plant the oleander in a specially prepared soil. From its natural location on the river bank, it is used to soil that is occasionally a victim of flooding. This brings in a lot of nutrients, supplies the soil with plenty of lime and compacts it heavily. The garden soil should therefore also be adjusted to a tolerable pH value for oleanders, which according to literature should be between 6 and 8.3. If necessary, the soil should be supplied with lime after checking the pH value. You should mix in some compost as a nutrient cushion and ideally also clay.

Water is really important for your oleander and it never lacks in its natural environment by the river. That’s why he wants plenty of water in warm weather, better too much than too little. A plant that is often flooded on the riverbank is logically not very sensitive to waterlogging. The rose laurel is usually more than happy if you water it with this tap water in areas with very “hard”, i.e. calcareous water. He likes calcareous water much better than the beautiful, soft rainwater. But please not from the line you are currently using, plants don’t like an ice-cold shower any more than most people do.

Sometimes you can read that a rose laurel should never be exposed to the rain. This warning is based on the consideration that the double flowers of many oleander varieties cannot really cope with a heavy downpour in their development phase. The rest of the year, however, the oleander enjoys a downpour just like any other plant. The more frost-resistant varieties mentioned above can be planted freely in the garden anyway, they all have single and not overly sensitive flowers.

You should also fertilize your oleander very eagerly. As already indicated above, he is used to being supplied with plenty of washed-up nutrients. You can fertilize weekly or bi-weekly (depending on package instructions) with liquid fertilizer or add a special slow-release fertilizer at the beginning of the season. An NPK mixture 15/8/12 (15% nitrogen, 8% phosphate, 12% potassium) with magnesium and trace elements is the right fertilizer for the oleander.

Oleanders in the bucket

However, most oleanders in most parts of Germany do better in a tub. The soil in the bucket should also be based on the needs of the Mediterranean plants, e.g. For example, don’t just reach for regular peaty substrate sold in bags. If you want to preserve your natural environment, you should avoid using peat unnecessarily. However, these substrates are also usually adjusted to a pH value that is far below what an oleander prefers. It is therefore best to use normal (garden) soil for your oleander, the pH value of which can be increased if necessary by adding lime and mixed with a little compost and clay is a wonderful soil for your oleander.

A flowering plant in a pot should always have enough space for its roots to develop. Only then can the plant also grow magnificently in the visible area. Young plants grow eagerly. You should therefore get a slightly larger pot every year. Older plants then develop more slowly. They will be repotted as needed. This need is given when the bale consists almost entirely of root mass. This can be the case after 5 years, but it can also take up to 10 years. Eventually a solitary plant will grow so large that you can no longer give it a larger container. Then it is still “repotted” every few years in the same bucket.

You should then also prune the root ball right away, after resetting the bucket is filled with fresh soil. You should also cut back some shoots in the upper area, so you restore the balance between the roots you just cut and the plant mass that needs to be cared for above ground. Spring is the best time to repot a container plant. Give your oleander a little more time after moving from its winter quarters, when it feels really comfortable outside again, it gets its new pot.

The potted plants are also best watered with (preferably hard) tap water. Here the liquid supply requires special attention, because pots can dry out very quickly due to the limitations of the soil. When it is very hot, you may have to water an oleander in the bucket every day.

Once the soil in the bucket dries completely, you would have to look for a large container in which to immerse the entire bucket. If you just watered such parched soil from above, the water would just pass through without nourishing the plant. It is therefore more convenient and better for your plant if you do not let it dry out in the first place. You can take advantage of the fact that oleander is one of the few plants that like to live with “wet feet” all the time. So you can keep the coaster filled with water all the time.

The oleander is fertilized in the bucket like the oleander in the garden soil. Only the amount of fertilizer should be calculated a little more cautiously. You don’t have to supply the same amount of soil in a bucket as when the oleander is in the garden.

Cut rose laurel

The oleander is one of the woody plants: if it were allowed to grow uncut, it would develop bare, woody branches inside, with a few shoots with leaves and flowers growing at the outer end. As with all woody plants, pruning is a constant struggle to push back this woody growth. You remain victorious if you rid your oleander of the oldest shoots by regular pruning. It will continue to branch out and continuously develop young, flowering shoots.

The best time to cut is in spring, when your oleander wants to grow anyway and develop new shoots. But you can also cut off bare shoots in autumn. You can even prune the entire rose laurel if it no longer fits into its winter quarters. Can be thinned out all year round. The worst thing that could happen to the willing oleander after a wrong or too radical pruning is the failure to flower next summer.

The shoots can always be cut away directly at the base. That’s why you don’t usually see that an oleander is constantly being pruned. “Stumps” or “coat hooks” are only left standing if new shoots are to be formed from these remains. However, an oleander naturally develops new shoots from the rootstock again and again, so this is not necessary for him. If your oleander is bald, it needs a radical cure. You have to rejuvenate it by severe pruning. Do not look for more than 3 to 5 well-spaced, strong young shoots, which you cut down to about 20 cm. The oleander will not flower for a while, but will completely rebuild itself.

The flowers, on the other hand, should not be cut off: if inflorescences have not yet opened by autumn, then next year they will continue to develop. Even when they have faded, the flowers can remain on the bush because new flower buds will sprout twice from each inflorescence. After the second flowering you can remove dried remains, but that doesn’t have to be the case. If you are unsure about the stage of development of the flowers, simply leave everything on when in doubt, the earlier the oleander will bloom next year.

Be careful when cutting: All parts of the rose laurel plant are highly poisonous and must not be left lying around unattended. When cutting and repotting, you must ensure that no milky sap from the plant, e.g. B. gets into the bloodstream via a wound, after work you should wash yourself and the tools thoroughly.

multiply

Oleander cuttings can be rooted. You could e.g. B. put the shoots cut off in spring in pots with soil, after about four weeks roots should have formed. In principle, it is also possible to propagate oleanders from commercially available seeds. You can even try to continue growing your own oleanders by maturing the infructescences on the flowers and harvesting the seeds. The light germs are simply scattered in pots and supplied with moisture evenly. You need an ambient temperature of around 23 degrees. After about 14 days, the first seedlings should appear. However, the rose laurels obtained from seeds sometimes only flower after years, and the oleanders from your own seeds will not show the flower of the mother plant, but reflect on their ancestors,

hibernate

Detailed information on care in winter in the special article on oleander overwintering .

An oleander in the garden should really only be planted there if you know that the chosen variety can withstand the normal winter temperature in your area. As a precaution, however, you can definitely give it winter protection from piled up mulch, perhaps with fleece over it, so that it does not suffer any damage if it gets unusually cold.

Oleanders in pots like to be kept cool (5 to 10 degrees) and bright in winter. The brighter it is allowed to hibernate, the more flowering plants it will have ready. Before the potted plant migrates to its winter quarters, it is of course checked for pests and treated if necessary. You should leave the container plant outside for as long as possible. Most rose laurels can remain outside until the first frosts of minus 5 degrees. In the new year, the tub is allowed to go outside again as early as possible. The oleander in the winter quarters needs a little less water, but must not dry out. He is not fertilized. In the spring you can then place it directly in the full spring sun. It is one of the few plants where you do not have to worry about burns.

If you don’t have a suitable bright room available, you can also try to get your oleander over the winter with the help of a dark room that is guaranteed to be frost-free. Then it is all the more important that you put it in as late as possible and put it outside again as early as possible. In this way he suffers as little as possible from the lack of light. In such a case, a combination of “packing in winter protection” and “putting outside as soon as possible” might be advisable. Maybe in such a way that your oleander is only placed in the dark room when the temperatures make it absolutely necessary and (well packed) can always take a light bath in between if it is not too cold. In order to make the multiple putting in and taking out bearable, you could then place the rose laurel on a mobile trolley. At least if your alternative room is at ground level, that helps a little.

pests and diseases

If a rose laurel gets yellow leaves, this can be completely normal at first. The oldest leaves eventually turn yellow and the oleander sheds them after a while. If a lot of leaves are turning yellow in a short amount of time, the first thing to think about is a nutrient deficiency. If your oleander loses leaves inside the plant, this is usually due to a lack of water.

The oleander is mainly attacked by scale insects and occasionally by spider mites or thrips. These animal pests can be combated mechanically, but it is also possible with plant protection products based on rapeseed oil.

Oleanders imported from the south are usually infected with oleander canker, a bacterial disease that manifests itself in the form of hump-like protuberances on the upper side of the leaves and in darkly colored ruptures on the shoots. There is no other way of combating oleander canker except a deep pruning into the healthy wood.

Conclusion
The oleander is an extremely decorative flowering plant which, if cared for correctly, will spoil us with a veritable sea of ​​flowers. A tip for choosing a variety: The oleanders from the supermarket or from the garden center are often bred for (too) strong growth. This does not make them very resistant and often leads to the plant soon going beyond its winter quarters. If you want to be able to enjoy an oleander for a longer period of time, it is worth buying it from a specialist breeder. Among them are companies that grow domestic oleanders without diseases (even young plants without the oleander canker that almost always comes with southern imports).