Feeding hibiscus: when & what fertiliser? - Plantura (2024)

The hibiscus stands out with magnificent flowers – at least with the right care. Find out everything you need to know about feeding hibiscus here.

The hibiscus (Hibiscus) is an enrichment for the home windowsill or conservatory not least because of its summer blooms. The right hibiscus, skilfully overwintered in a protected location, can bring the Hawaiian flair of the subtropical plant to your garden as well – at least in mild regions. The hibiscus actually comes from Asia. In order for the charisma of the mallow family (Malvaceae) to take hold indoors as well as outdoors, the striking flowers of the hibiscus are a must-have. These appear – if the hibiscus is properly cared for – between June and October every year in bright colours. Such an imposing flower naturally depletes the plant reserves and needs a regular supply of nutrients. In this regard, two representatives of hibiscus occupy an important place on our windowsills and in our gardens in particular, which want to be supplied with sufficient nutrients. Chinese rose (Hibiscus rosa-sinensis) is a classic on the warm windowsill, while garden hibiscus (Hibiscus syriacus) makes the garden shine.

Proper nutrient intake and composition will keep your hibiscus blooming profusely, rather than shedding its leaves and flowers in defiance of neglect. This article answers the most important questions about feeding your hibiscus, so that your hibiscus in the summer will show its most beautiful flowers in thanks.

When to fertilise hibiscus?

Below are the different times when it is advisable to fertilise the hibiscus.

Feeding hibiscus during cultivation

If you want to grow or propagate your own hibiscus despite rather low germination rates, start providing nutrients from the second month. In this case, the small plant is first fertilised with diluted liquid fertiliser. You should gradually approach the concentration specified by the manufacturer to slowly accustom the hibiscus to the nutrient intake.

Feeding hibiscus when planting

When planting in the spring, you can provide the nutrients for the next flowering. You can do this by mixing mature compost or another slow-release fertiliser such as our Plantura Flower Food into the garden soil. This is especially recommended for a hibiscus pot culture because you have the opportunity to properly enrich the soil with nutrients when planting. With an already planted pot, mixing fertiliser into the soil is usually a tricky business. After planting, you can still apply a layer of mulch in the root zone.

When to fertilise indoor hibiscus?

Due to the small volume of soil in the pot, it is better to regularly resort to fertiliser for a hibiscus in pot culture. Provide your garden hibiscus with adequate nutrients once a week during the growing season from March to October. Here, the choice can also fall on a mineral fertiliser variant because the soil life within the pot is usually rather sparse anyway. If fertiliser sticks are given as an alternative, the fertiliser application is reduced to the specified duration of action.

When to fertilise a garden hibiscus?

Garden hibiscus has the same nutrient needs as the species that frolic on the windowsill, but with roots in the garden soil, it has entirely different sources of nutrients available to it. Here you can also opt for the quickly available mineral fertiliser variant from March to October but it is more convenient to reach for an organic slow-release fertiliser. This is used in much larger sections, usually a single application in the spring is enough. You can therefore combine the fertiliser application with the annual pruning of your hibiscus. Only a professional pruning helps the hibiscus to unimagined flowering power.

If you additionally opt for a natural fertiliser, you will not only do animals and small children of your household a favour due to its high compatibility. They also protect the environment and soil life, which is important for the nutrient cycle.

Summary: When to fertilise hibiscus?

• When planting, mix mature compost or organic slow-release fertiliser into the planting soil and apply a mulch layer
• Fertilise at regular intervals from March to October

Hibiscus fertiliser: how and with what to fertilise hibiscus?

Even though the hibiscus is a plant originally from Asia, fertilisers suitable for Mediterranean plants, as well as Asian flowering plants, are offered in stores. Even special hibiscus fertilisers are available. These promise a healthy leaf mass, as well as beautiful flowers. Here, the hibiscus needs the right combination of nitrogen, phosphorus and potassium. An NPK fertiliser with a ratio of 7 – 6 – 5 is said to be ideal for this, but a normal flower fertiliser will also satisfy flower-bearing plants all around. You should pay particular attention to the supply of the trace elements sulphur, boron, copper, iron, manganese, molybdenum and zinc.

In late summer, or early autumn at the latest, you should also switch to a potassium-based fertiliser. This makes the plants more resistant and fit for the winter. This is particularly beneficial for garden hibiscus (Hibiscus syriacus) planted out in a bed. However, species such as Chinese rose (Hibiscus rosa-sinensis) also benefit from the additional strengthening in the winter quarters. Our Plantura Flower Food offers a nutrient ratio of 4 – 2 – 7 (NPK), which is gratefully accepted by pretty much every flowering plant. In addition, it provides extra potassium for the cold season. Accordingly, your hibiscus will be well taken care of all year around. At the same time, this fertiliser offers many advantages for the gardener and their green environment:

• It promotes soil life, i.e. earthworms, but also helpful bacteria
• The ingredients all come from organically controlled cultivation and are completely animal-free
• The nutrients are available over a long period of time and are thus released to the soil and the plant in a well-dosed manner

Expert tip: Even the best fertiliser is of no use to you with hibiscus if waterlogging forms because the watering water cannot drain away. Therefore, when growing in pots, be sure to use a pot with a drainage hole and apply a layer of drainage.

Feeding hibiscus: instructions for application

Your hibiscus needs a variety of nutrients for blooms that make eyes and mouths drop open. These are taken from the soil surrounding the roots. Especially for potted crops, a regular supply of these nutrients is therefore essential. After all, the reserves in the soil do not simply replenish themselves. Even in the flower bed, the natural supply of nutrients is usually not enough to maintain the nutrient supply for years. In addition to an optimal supply of nutrients, a fertiliser with a high potassium content – such as our Plantura Flower Food – provides cold-sensitive plants with strength for harsh winters. Here is a quick guide to expertly fertilising your hibiscus:

1. Before planting, work 100 – 150 g/m² (well-filled 0.2-litre jar) of our Plantura Flower Food into the top soil layer
2. Water the soil and freshly planted hibiscus well so that the granules can dissolve optimally
3. During maintenance fertilisation in the spring, you should fertilise again with 80 – 120 g/m² (0.2-litre jar) per plant

Feeding hibiscus naturally

Although a hibiscus does need a brisk supply of nutrients, that does not mean you have to resort to the mineral fertiliser club. On the contrary, you can avoid the use of fertiliser one or two times by using an organic fertiliser.

You can work the nutrients into the top layer of soil in the root zone with a garden tool. Those who resort to a completely natural form of fertilising can strengthen their hibiscus by fertilising with Patentkali potash. The additional supply of potassium ensures faster maturation of the shoots. The magnesium also provides a green and healthy appearance. Here, about 40 grams per square metre are used for trees and ornamental shrubs. However, when growing hibiscus plants in pots, applying organic fertilisers such as compost is usually difficult. In addition, the smell does not exactly contribute to the tropical feel-good ambience.

Therefore, slow-release fertilisers in liquid or granular form are more suitable. Our Plantura Flower Food ensures that you do not need to make any compromises in terms of natural compatibility. The almost exclusively vegetable ingredients come from controlled, organic cultivation. This way you can provide your hibiscus with long-term, convenient and environmentally friendly care, even in a pot. For better resistance, you can also supplement the fertiliser with rock flour. This contains many minerals and trace elements such as silica, iron, manganese and molybdenum.

Fertilising hibiscus minerally

Mineral fertilisers are highly concentrated and supply nutrients according to the principle of rapid availability. Your plants will be supplied with all the necessary nutrients in no time at all. This can be beneficial if your plant is showing signs of deficiency. However, with the wrong dosage, these benefits can also quickly lead to damage from overfertilisation. In addition, the abundance of plant food is often flushed out as quickly as it is available. Therefore, always fertilise exactly according to the manufacturer’s instructions. During the growing season from March to October, you should fertilise hibiscus in pot or container culture about once a week. In doing so, your plants will be optimally supplied and less fertiliser residues end up in the groundwater. However, to minimise the risk of stress to the soil and plant, it is recommended to use an organic fertiliser.

Feeding hibiscus with home remedies

Small home remedies can have a big effect – and this is also true for fertilising houseplants and garden plants. Coffee grounds, crushed banana peels or tea grounds mixed in with the soil will provide a good supply of everything your hibiscus needs. You can alternatively water with liquid manure or decoction from plant residues or vegetable water. Potassium salts such as Epsom salt provide an extra load of potassium for good winter hardiness.

Read this article for more tips on how to best care for hibiscus.