- Fertilize oleanders: the right time
- Fertilize oleander: Deficiency symptoms
- Fertilizer for oleanders: How and with what to fertilize?
Help the development of the site, sharing the article with friends!
A balanced nutrient ratio is required for a magnificent oleander blossom. You can find out when, how and with what to fertilize oleanders here.
Even though Vincent van Gogh is best known for his love of painted sunflowers, the oleander (Nerium oleander), also known as rose laurel, also found a place in the colorful world of the artist. No wonder, because the delicately feminine flowers still enchant hobby botanists and friends of beautiful things to this day. In order for these striking flowers to appear in harmonious white, yellow to pink-red tones throughout the summer, the plants need more than just warmth and sun. A sufficient supply of nutrients in the form of regular fertilizer application should also be ensured for these heavy feeders, especially in tub culture. At the same time, you should pay attention to the special needs of the oleander in terms of soil conditions.
Oleanders spread a Mediterranean ambience within the native flora in pots on the terrace and balcony, sometimes also planted out in beds. But in order for the flowers to last from mid-June to September, the plants need a lot of nutrients. So that you know how you can use the right fertilization to increase the number and size of flowers in your oleander, we explain when, with what and how often you should fertilize your plants.
Fertilize oleanders: the right time
As with every plant, the right time for oleander also plays an essential role in successful fertilization.
Fertilize oleanders when planting
You can already bed your green darling in plenty of nutrients when planting or repotting your oleander. For this, mature compost or another organic long-term fertilizer is mixed into the used soil. An additional enrichment with rock dust also provides your oleander with all the important trace elements and a load of lime, which ensures the right soil pH value between 5.8 and 7.0. After repotting or planting, you shoulddo not apply fertilizer again until six weeks at the earliest.
Fertilize oleanders in spring and summer
Otherwise, the oleander is fertilized for the first time after leaving its winter quarters in spring. This start fertilization takes place as soon as the outside temperature is around 15 °C. Now the growing season of your Mediterranean plant begins. This is usually around April or May. The plant itself also signals when it needs nutrients again. If the leaves of your oleander slowly turn darker again after the hibernation, the time has come for the first fertilization. Fertilize your oleander about once a week to every 14 days from spring to the end of August. If a long-term fertilizer is used, the initial fertilization in spring is sufficient, as is further fertilization in early summer. This choice not only saves you one or the other application of fertilizer. If you use an organic long-term fertilizer such as our Plantura organic flower fertilizer, you also protect your oleander from over-fertilization. In addition, they not only promote the he alth of your plant, but that of all soil life.
Fertilize oleanders in autumn
Starting in autumn, the fertilization of the oleander is stopped so that the newly formed shoots have enough time to mature until winter. To support this maturing process, autumn fertilization with potash fertilizer can be carried out in August. The potassium supports the rapid maturation of the shoots and makes your plant more resistant to low temperatures. It should be borne in mind that even with this support, the Mediterranean shrub should not be exposed to temperatures below -5 °C. In winter, the fertilization is then completely stopped, the plants need their hibernation. In this they run on the back burner and do not need any additional nutrient supply.
Summary: The right time to fertilize oleanders
- When planting or repotting, mature compost, rock dust or another long-term fertilizer is mixed into the soil; then no fertilizer for at least 6 weeks
- From spring (March/April) to the end of August, fertilize regularly every 1 - 2 weeks; when using an organic long-term fertilizer such as our Plantura organic flower fertilizer, a single fertilization in spring and another in early summer is sufficient
- Autumn fertilization in August with potash fertilizer for greater resistance in winter
Fertilize oleander: Deficiency symptoms
If the otherwise always green leaves of your oleander turn yellow and fall off, this can be due to deficiency symptoms such as a lack of water or nutrients. However, it can also be part of the normal life cycle of the oleander, as the leaves are only two years old and then say goodbye. Before that, all the nutrients contained in the leaf are released to the plant. As a result, the yellow discoloration occurs before the leaves are shed. You should therefore only worry about your oleander when many leaves are shed over a short period of time. The way the leaves change color before they are dropped can also make it easier to find the reason. Pale leaves with visible veins and no or poor flowering indicate nutrient deficiency.
Emergency fertilization with mineral fertilizer helps here. This is available more quickly than the organic variant, which is an advantage when combating a deficiency symptom quickly. However, make sure that the administration of highly concentrated mineral fertilizers does not turn the deficiency into over-fertilization. Often, an undersupply of nutrients is not due to too little fertilizer, but to an incorrect soil pH value due to the use of very soft irrigation water or acidifying nutrient sources such as ammonium fertilizer or coffee grounds as fertilizer. These lower the pH value in the soil and thus limit the availability of nutrients. This can be remedied by repotting, watering with hard tap water or fertilizing with rock flour or eggshells.
Fertilizer for oleanders: How and with what to fertilize?
Specialist fertilizers for oleanders or Mediterranean plants are available in specialist shops. In addition to the important primary nutrients nitrogen, potassium and phosphate, these also contain trace elements such as magnesium, boron, copper, iron, manganese, molybdenum and zinc. Especially in pot culture, these minerals are quickly depleted due to the low soil storage capacity and the oleander's highly consuming character. However, any other flower fertilizer can also be used. If important trace elements and minerals are missing in the fertilizer, you can also give rock flour. Also, make sure you avoid very nitrogenous fertilizers so that your oleander puts its energy into flowering profusely and not into strong growth.
With an NPK ratio (i.e. nitrogen to phosphate to potassium) of 4 - 2 - 7, our Plantura organic flower fertilizer is an ideal source for covering the nutrient requirements of your oleander. The extra potassium also supports the frost resistance of the plant in winter, because it accelerates the lignification of the shoots. Due to the complex form in which the organic components are almost exclusively present, the nutrients are slowly released into the soil. So you only have to use fertilizer once a year and avoid harmful over-fertilization. If you want to maximize the number and size of flowers and promote reblooming, it is best to fertilize with a phosphorus fertilizer. This is given at most every four weeks.
Organic long-term fertilization for oleanders: instructions and dosages
Our Plantura organic flower fertilizer with organic long-term effect offers you a long-lasting and environmentally friendly supply of all important nutrients, because an all-round supply of your oleander is possible even by excluding animal products and using almost exclusively organic sources. To ensure that fertilization is successful, we explain step by step how to use our Plantura organic flower fertilizer correctly.
- Before planting, work 100 - 150 g/m² (well-filled 0.2 liter glass) of our Plantura organic flower fertilizer into the top layer of soil
- Water the soil and freshly planted oleander well so that the granulate can be easily loosened
- For maintenance fertilization in spring, you should fertilize another 80 - 120 g/m² (0.2 liter glass) per plant
Particularly when growing in containers, it is important not only to think of the usual macronutrients such as nitrogen, phosphate and potassium. Since oleander is one of the heavy consumers, trace elements such as iron, magnesium and calcium should also be applied. Because in the limited conditions of a bucket, the supplies stored in the earth are quickly used up. This can be remedied by rock flour, which is spread on the ground in the root area once a year in spring. Then it is poured vigorously. Apply 150 to 300 g per m² depending on the lime content of the soil. The more calcareous the soil, the less you should fertilize. At the same time, the rock flour has the advantage that the soil pH value is buffered for the Mediterranean plants. Especially wellthe plants feel at a pH between 5.8 and 7.0. The plants here do not have very high requirements.
Fertilize oleanders with minerals: Blaukorn and Co.
Especially with plants like the oleander, which are usually kept in tub culture, you can also use mineral fertilizers. However, make sure to fertilize blue grain and Co. according to the manufacturer's instructions and also supply the necessary trace elements. Because even if over-fertilization is not life-threatening for the oleander, it is not good for the he alth and appearance of the plant. Over-fertilization is indicated by a brown discoloration of the leaf edges.
The damage to the fine roots of the plant caused by the salinity of the soil remains invisible. If you over-fertilize the tub with your oleander, rinse it with plenty of water without waterlogging and only fertilize again when the plant has recovered. This can sometimes take a long time because the damaged leaves have to be shed and replaced with fresh leaves.
Fertilize oleanders with home remedies: coffee grounds and co.
Even what is usually declared as waste can still serve as a source of nutrients for the oleander. Better to let coffee grounds or banana peels end up in the ground than in organic waste. Dried and incorporated into the plant substrate, they offer your oleander a cheap and organic alternative to purchased fertilizers. However, coffee grounds have an acidifying effect on soil. If your oleander becomes too acidic, the availability of nutrients in the soil will be limited.
Calc can help here. And in this case, too, organic waste can become a treasure trove: simply mix in fertilizer made from crushed eggshells as a lime source. If you use rock flour to supply your plants with important trace elements, you can also try preparing manure from plant residues as an alternative fertilizer, because rock dust reduces the unpleasant odor of the manure and makes it an attractive fertilizer option. In this way, you can give plant residues such as weeds in the garden a useful second use.