How to fertilise perennials

Just like people, perennials need nutrition to grow and bloom optimally. This nutrition can be provided in the form of fertilisation. But how and when is this best done?

Basic requirements

The basic requirements of perennials are light, heat, water and nutrition. A part of the nutrition is already present in the soil in the form of minerals; for the other part plants depend on fertilisation. Fertilise twice a year: in spring and in late summer.

Extra boost

Spring fertilising is the most important: it is the foundation. Fertilising in March gives your perennials an extra growth boost. Fertilising in late summer (July/August) is necessary to give the plants strength before entering the winter period.

Top condition

Ask for organic fertiliser at your garden centre or hardware store. Organic fertiliser has several advantages compared with chemical fertilisers. They allow plants to grow more gradually and improve the soil. Garden fertiliser, ornamental garden fertiliser or border fertiliser are suitable for perennials. Check the packaging for the correct dosage; too much fertiliser actually gives weaker plants energy. Sprinkle the fertiliser on the soil near the plants. The fertiliser will allow them to grow and flower optimally and allow the soil to remain healthy and fertile. In this way, you can keep your perennials in top condition and enjoy them year after year.


  • Do not fertilise when the foliage is wet; if the fertiliser sticks to the leaves, there is a risk of leaf burn.
  • Also apply a thin layer of green compost to the soil.
  • The foliage will tell you whether your perennial is getting sufficient nutrients. For example, smaller and lighter coloured leaves indicate a nitrogen deficiency (N) and leaves that turn yellow between the veins indicate a lack of magnesium (Mg).

How to fertilise perennials How to fertilise perennials

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