Oleander: how to multiply it by taking a cutting, even in a pot

Until a few years ago, the oleander was the symbolic flower of the sea and lake shores. Today, its bright colors and vanilla scent have become the hallmark of metropolitan summers. Indeed Nerium oleander – this is its Latin name – it is one of the plants that are best able to tolerate the heat peaks and the pollution that accumulate between buildings, where it is one of the easiest bushes to cultivate in sunny situations.

Despite its exotic appearance, we are talking about a curious autochthonous species which, according to some palaeobotany studies, represents a residue of the ancient flora that already thrived around the Mediterranean basin 23 million years ago (when there were on average six degrees more to date and much more CO was circulating₂ in the atmosphere). So let’s consider it fully a sustainable plant proof of climate change.

Early summer is the best time to multiply oleander placing a sprig in water to root (i.e. a cutting). This is also the most beautiful way to take home a souvenir from a beach holiday. Proceeding in this period, we will have new seedlings already independent before winter and ready to flower from next spring. Furthermore, by adopting this technique, we will be able to transform our balconies into small nurseries to fill the desolate condominium gardens with flowers or to give plants to those involved in social projects or recovering abandoned suburbs. Here’s how to proceed step by step.

Oleander: how cuttings are made in water

To multiply the oleander by placing a piece of it to root in water, we identify a semi-woody branch (avoid newly sprouted green shoots and too old branches). The chosen cutting, about 25 centimeters long, must not have flowers or buds. Using shears, we cut the branch an inch below a node, i.e. below where the leaves attach. Next, we remove the top of the cutting by cutting it above the third or fourth node from the bottom. After we remove almost all the leaves leaving only the topmost ones. Then we shorten the leaves remaining at the top of the cutting, cutting them from half to one third of the length. This operation serves to reduce the leaf surface, preventing the cutting from dehydrating. In extreme synthesis, we obtain a cutting, eliminate the leaves along the stem and reduce the tuft at the top by half. At this point, we rinse the base of the cuttings to eliminate the latex that flows from the wounds (that’s exactly what it’s called, with an “L”), which otherwise solidifies and creates a “cap” that prevents the twigs from drinking. We put the cuttings in a glass jar with two nodes immersed in water and place them in a bright place, not in direct sunlight. Instead, we do not use a bottle, because the narrow neck does not circulate oxygen.

Oleander cutting: how long does it take to grow?

Let’s change the water to the cuttings daily to avoid bacterial proliferation and if we see turbidity around the twigs, rub them lightly with our fingers under the tap to clean them. Within ten days we will see white dots appear on the twigs: in two weeks these lenticels will turn into roots. When these become 4-5 centimeters long, we transplant them into the ground (don’t wait too long, otherwise the rootlets will break during the operation). We prepare pots of about 20 centimeters in diameter, fill them halfway with good soil, carefully place three cuttings in each pot and then fill with earth around the new seedlings, press the substrate around the cuttings with our fingers and water abundantly. Then we place the pots in the shade and water them regularly so they never dry out completely. After a month after transplanting, we gradually move the pots to the sun. The new shoots will grow quickly and the oleander will rise at a rate of one meter per year or more.

Is oleander poisonous?

For all the operations suggested above, and in general when we prune the oleander, we must use gloves or wash our hands thoroughly with soap immediately afterwards, avoiding touching our eyes and mouth, because the milky sap of the plant is toxic if it comes into contact with our mucous membranes, as are the leaves and flowers if ingested. Of course, we don’t have to use its branches to light the barbecue either. It is also the same for the other plants belonging to the Apocynaceae family, for example false jasmine and plumeria, and in general for many ornamental varieties – from hyacinth to cyclamen, to dieffenbachia – which are poisonous. Don’t worry about pets, from cats to turtles, because in general they are guided by instinct and “sniff out” danger. On the other hand, poison is what the plant uses to defend itself against parasites and herbivores, therefore it is part of the ingredients of its resistance to adverse conditions.

The red oleander is the most popular

In its wild form, which in Italy survives in the riverbeds of Calabria and Sardinia, the oleander has simple pink flowers (a trumpet with only five “petals”), but in gardens we are used to seeing variety of each color, because starting from the end of the seventeenth century our oleanders were crossed with those with double flowers (ie full of petals) and perfumed ones brought from India. The red oleander, which is actually a very strong amaranth, is today the most popular, followed by the white, yellow and apricot hybrids. Among the most fragrant are ‘Mont Blanc’, ‘Luteum Plenum’ and ‘Splendens Giganteum’. They are also very interesting the new dwarf oleanders such as ‘Maravenne’, Petite Salmon’ and ‘Petite White’up to one meter high. If we are interested in one of them in particular, we must reproduce it by cuttings, because the plants cross each other and those born from seeds are always a surprise. Alternatively, we buy a plant labeled with the name of the variety.

Oleander: characteristics and pruning

The oleander is an evergreen bush that blooms several times during the summer and within three or four years it tends to form a large dome about four meters high and wide. To contain its size we can prune it, shortening all the branches after the first flowering of summer, in order to have new “shoots” ready to bloom again in autumn. If, on the other hand, we want to cultivate it in the form of a small tree, we must let a single branch grow by fixing it to a brace and eliminate all the lateral shoots as they reappear. The crown of the tree oleander tends to get heavy, so it is advisable to prune it every year. Wild oleander can withstand frosts of -7°C below zero for a few nights, but hybrid varieties tolerate nights where the thermometer drops to -12°C (among the most frost-resistant, ‘Hardy Pink’, ‘ Hardy Red’, ‘Double Yellow’, ‘Mathilde Ferrier’, ‘Provence’, ‘Sister Agnes’, ‘Petite Salmon’, ‘Splendens’); snow, on the other hand, is always a problem because it causes the branches to collapse, so in the mountains we can plant the oleander against a south-facing wall. Once they have taken root well (i.e. from the second year), oleanders grown in the ground do not need watering.

The oleander in a pot

Oleanders are also easy to grow in pots, as long as we have enough sun and plenty of air. If they have little sun they do not flower, while in situations of stagnant air (for example in small closed courtyards), they can get sick with scale insects. Those most suitable for planters belong to the dwarf varieties, but even the classic oleanders can grow well in a container because the little earth in the pot in itself has a “dwarfing” effect on the plant, and over time we will see ever smaller and smaller leaves. growth reduced to a few centimeters per year. The ideal is to use a pot of 50 centimeters in diameter filled with field earth or with citrus soil. In this case, however, the rule that is always valid for potted plants applies, which are dependent on our care because they cannot obtain humidity by themselves: we must water regularly and fertilize from spring to late summer. Very important: let’s remember to irrigate the oleander and all the evergreen plants in pots even in winter.

The oleander in the hedge

The oleander is one of the easiest evergreen hedge plants and has many advantages, but let’s take into account that it grows a lot therefore we must intervene regularly with pruning if we don’t have much space available. Its branches are very elastic and resist wind blows well, even near the sea, as they tolerate saltiness, therefore we can create windbreak hedges either by letting the oleanders grow naturally, or by pruning them “against the wall”. Furthermore, unlike other species, they tolerate the radical competition of trees and they can also grow under pines and eucalyptus trees (which normally kill nearby plants), as long as enough sun arrives. In addition, they manage to be reborn from the roots after fires and after storms, so they work well for delimiting countryside and sea lands. If we want to use them for a mixed hedge, we can combine them with Mediterranean plants with which they normally grow in natural environments, such as tamarisk, chaste tree and strawberry tree.