The oleander has a special place in the family of generously flowering Mediterranean plants. With its dazzling flowers ranging from white to fuchsia to deep red, it transforms a simple balcony or terrace into a living tableau. But to reach this peak of beauty, the oleander needs a little help. And the cleverest gardeners have known this for a long time: a natural fertiliser that’s simple, accessible and devilishly effective.
At this time of year – mid-May – the plant enters its active growth phase, where everything is at stake for the coming months. Foliage, flower buds, root systems… everything is falling into place. So it’s the perfect time to enrich the soil with the right inputs. Forget chemical fertilisers with indecipherable labels: it’s natural materials, sometimes already in the kitchen, that will produce the most beautiful floral displays.
Mid-May: the ideal time to stimulate flowering
If temperatures have stabilised, the risk of frost is over and the plant is starting to produce its first buds, then the signal has been given. Now is the time to enrich the soil, not in July, when flowering has already begun.
The Oleander is a generous but greedy plant. It needs rich, well-drained soil with a sufficient supply of mineral elements to flower for a long time. A simple lack of potassium or magnesium can make the difference between a luxuriant plant and greenish foliage without a single flower.
Mature compost: the gardener’s brown gold
Compost is undoubtedly the best ally of the Oleander when it is in full bloom. Well-decomposed compost provides a balanced mix of nutrients: nitrogen for the foliage, phosphorus for the roots and potassium for the flowers. This natural mixture stimulates the soil’s biological activity while improving its structure.
A two-centimetre layer at the base of the laurel, without directly touching the crown, is enough to nourish the plant for several weeks. It’s a gentle, gradual boost, perfectly suited to summer blooms.
Coffee grounds: the little extra for gardeners in the know
Some people throw it in the bin, others give it to their plants. Coffee grounds are rich in nitrogen, which stimulates new leaf growth, as well as secondary minerals that support the plant in times of stress.
Incorporated into compost or spread in a thin layer on the soil, it improves soil structure and encourages water retention. In small doses, it becomes a growth activator that prepares the plant to flower powerfully.
Eggshells: limestone reinforcement
Often overlooked, eggshells are a valuable source of calcium, an element that contributes to strong plant tissue and a healthy root system. Finely crushed and spread at the foot of the plant, they slowly release their minerals into the soil.
This supplement is particularly useful if the plant is showing signs of weakness: limp stems, dull foliage or falling buds. It’s a natural way of strengthening the plant without rushing it.
Wood ash: the potassium boost
The Oleander, like all plants that flower abundantly, needs potassium to form its buds properly, open its flowers and prolong the flowering period. And one of the most accessible sources of this element is quite simply wood ash.
A handful spread around the plant, lightly scraped into the soil, is enough to provide a cocktail of essential minerals. But be careful: the ash must be free from combustion products (no coal or treated wood), and it must be used sparingly to avoid upsetting the pH balance.
With these carefully thought-out additions, the oleander will not only bloom, it will literally explode with colour, transforming the garden into a veritable summer scene. And it’s all thanks to nature’s simplest… and most effective.
