Feeding magnolies: when, how & the best magnolia feed


I am currently studying agricultural and food economics. As a keen hobby gardener, plants take up most of my free time. A few years ago, I got especially interested in herbs, which is why I completed my studies to become a certified herbalist in 2018.

Favourite fruit: apples, cherries
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In order for the magnolia to show its beautiful flowers, it needs the right fertilisation. We explain what you need to bear in mind when fertilising magnolias trees.

healthy magnolia flowers
Only a magnolia that is comfortable all around will produce such abundant flowering [Photo: nnattalli/ Shutterstock.com]

Every spring we are enchanted anew by the rich flowering of magnolias (Magnolia). In order for your magnolia to thrive in the garden and reach this kind of flowering achievement, it is important to provide it with sufficient water and nutrients. Even the location you choose when planting can have a significant influence on the growth of your magnolia. In this article we explain which location is best to choose and how you can support your magnolia with the right fertilisation.

Magnolias have a relatively high demand for nutrients. As always, it is important to consider the individual stages of the plant’s development when fertilising according to its needs. Below we explain when and with what you should fertilise your magnolia and how best to go about it.

When to feed magnolias

The best time to plant magnolias is in autumn (October/November), when the plant is in winter dormancy. In harsher locations, however, spring planting (by April at the latest) is recommended. Depending on the species and variety, magnolias prefer a sunny to semi-shady location in a sheltered position. The ideal soil is humus-rich, nutrient-rich and slightly acidic with a pH value of about 5.5 to 6.8. With a few exceptions, magnolias do not tolerate calcareous, alkaline soils. When choosing a location, make sure that there is sufficient distance between the plant and other trees and shrubs. In a solitary position, you should reckon with a space requirement of about four to eight metres in diameter. Soils that are too sandy are just as unsuitable for magnolias as those that are too loamy. To provide the plant with optimal starting conditions, it is best to dig a sufficiently large planting hole and mix the excavated soil with rhododendron soil. By the way, this special soil is also wonderfully suitable for shrubby magnolias that are cultivated in a pot or tub.

Every year in spring (March/April) you can fertilise your magnolia with mature compost. This is applied as a thick layer to the root disc – the circular area around the tree – and lightly worked in. However, be especially careful not to damage the shallow roots just below the soil surface. If you do not have your own compost, you can also use a magnolia feed from a specialist shop. The best magnolia tree fertiliser is a slow-release fertiliser of organic quality such as our Plantura All Purpose Plant Food. This is particularly gentle on plants, soil and animals in the garden.

All Purpose Plant Food, 1.5kg
All Purpose Plant Food, 1.5kg
  • Perfect for a variety of plants in the garden & on the balcony
  • Promotes healthy plant growth & an active soil life
  • Long-lasting fertiliser that is free from animal products - child & pet friendly

Potted magnolias need regular fertilising from this point on (every fortnight). Rhododendron or bog bed fertiliser, for example, are very suitable for this. For planted magnolias, no further fertilisation is usually necessary as long as no symptoms of deficiency are visible on the leaves. However, if you still want to do something good for your darling, you can apply a further magnolia fertiliser three to four weeks before flowering or spread some rhododendron soil on the root disc. The different flowering times of the individual species should be taken into account. While tulip magnolias (Magnolia x soulangeana) open their flowers as early as April, evergreen magnolias (Magnolia grandiflora) and summer magnolias (Magnolia sieboldii) usually take their time until May or June. A layer of bark mulch also ensures that the soil is kept moist and does not dry out during the summer months. A final compost application is recommended in autumn to ensure that your magnolia survives the winter.

Summary: When to fertilise magnolias?

  • Amend the soil with rhododendron soil
  • Basic fertilisation (March/April) with compost or organic slow-release fertiliser
  • If necessary, a second fertilisation before flowering
  • Apply a layer of bark mulch
  • Last compost application in autumn

Feeding magnolias trees: what to use and how to do it

When it comes to plant food for magnolias and the optimal nutrient supply, many paths lead to the goal. In addition to organic fertilisation, you also have various options for mineral fertilisation. Particularly resourceful gardeners can even fertilise their magnolias with coffee. The advantages and disadvantages of the individual methods are explained below.

Fertilise magnolias organically: instructions

Especially with magnolias, you should make sure that you use fertilisers that lower the pH value or at least do not increase it. In addition to mature compost, horse manure or bone meal are also ideal for fertilising magnolias trees. It is best to sprinkle the bone meal on the root disc and then cover it with a layer of bark mulch about eight centimetres thick. This will gradually decompose and release additional nutrients for the plant. In addition, the mulch layer ensures that the soil is kept moist in summer. It also protects the cold-sensitive magnolia from frost in the winter months.

If you do not have access to such natural fertilisers, however, you can also find suitable products in specialist shops. Organic fertilisers may not work as quickly, but they are certainly the more sustainable choice in the long term and bring many advantages, such as the following:

  • Nutrient supply to the magnolia over a longer period of time through slow decomposition of the fertiliser via micro-organisms in the soil
  • Promotion of healthy soil life (good for micro-organisms, earthworms & co)
  • Protection of the environment by dispensing with chemicals

To ensure that you provide your magnolia with the ideal amount of nutrients, we have prepared precise step-by-step instructions for you below.

Organic Slow Release Fertiliser: Instructions & Dosage Quantities for Magnolias

Our Plantura All Purpose Plant Food is a fertiliser with an organic, long-term effect that is suitable for all plants that do not have a particularly high requirement for potassium. Therefore, it is also ideal for the nutrient supply of your magnolia. It consists exclusively of plant residues from the food, luxury food and animal feed industries and is therefore free of any animal products. The fertiliser in granulate form can easily be applied to the root disc of the magnolia and dissolved by watering. Thus, no mechanical incorporation into the soil is necessary.

  1. Before planting: work 100 – 150 g/m² (8 – 12 tablespoons) of our Plantura All Purpose Plant Food into the soil.
  2. Water the soil and the freshly planted magnolia well so that the granules can dissolve.
  3. Every year in spring, apply about 80 – 120 g/m² (6 – 10 tablespoons) to the root disc and water.
  4. A small amount of fertiliser about 3 – 4 weeks before flowering will once again support the plant optimally.
All Purpose Plant Food, 1.5kg
All Purpose Plant Food, 1.5kg
  • Perfect for a variety of plants in the garden & on the balcony
  • Promotes healthy plant growth & an active soil life
  • Long-lasting fertiliser that is free from animal products - child & pet friendly

Feeding magnolias with mineral fertilizer

In addition to organic fertilisation, feeding the magnolia with mineral fertilisers is also possible. Blue grain, liquid fertiliser & the like provide a quick boost of nutrients, but if used incorrectly there is an increased risk of overfertilisation. High concentrations of nutrient salts in the soil can not only damage the sensitive roots of magnolias, but can also leach into the groundwater. In contrast, organic fertilisers do not work as quickly, but they do help to improve the soil structure. Moreover, due to the slow decomposition by microorganisms in the soil, there is hardly any danger of overdosing.

Fertilise magnolia with home remedies: coffee grounds and the like.

Unbelievable but true: you can also fertilise your magnolia with coffee. Strictly speaking, you use the coffee grounds for this, which have ideally been dried beforehand. This way, mould does not form during storage. The actual waste product still contains many plant-important nutrients such as nitrogen, phosphorus and potassium. Organic materials also attract useful soil organisms – such as earthworms – and promote humus formation in the soil. The acidic natural fertiliser ensures a low pH value in the soil and is therefore wonderfully suitable for fertilising magnolias. Simply sprinkle small amounts of it on the root disc from time to time and work it in carefully on the surface.

Summary of how and with what to fertilise magnolias:

  • For organic fertilisation you can use compost, horse manure, bone meal or an organic fertiliser with a long-term effect.
  • Mineral fertilisation with blue grain and the like works quickly, but there is a danger of over-fertilisation.
  • Home remedies such as coffee grounds can also be used to fertilise magnolias.

More information on fertilising with homemade fertiliser can be found in this separate article.

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