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Fertilizing clematis

The question of the correct fertilization of clematis is often asked. The fertilizers in use today are more varied than ever before! Which fertilizer is used is a matter of opinion. What are the main differences between mineral fertilizers, stored fertilizers, slow-release fertilizers, liquid fertilizers, nutrient salts, mixed organic/mineral fertilizers, organic fertilizers, vegan fertilizers, organic stimulants and soil additives?


Overview of the various fertilizer substances that are commercially available

Fertilizer preparationDuration of effectMechanism of actionAdvantagesPractical tip
Mineral fertilizer Complex fertilizer2 – 3 weeksWater-soluble granules, dissolves quicklyFast initial effectNo long-term effect
Stock fertilizer Complex fertilizer6 – 12 weeksGranules dissolve slowly over timeEasy to useHardly any overfertilization
Slow-release fertilizer Complex fertilizer3 – 12 months depending on the preparationCoated fertilizer with membrane effectContinuous nutrient releaseFamiliarization helpful and improves the effect
Liquid fertilizer Complex fertilizer5 – 7 daysDissolved in irrigation waterImmediate effectShort effect
Nutrient salt complete fertilizer, single-nutrient fertilizer7 – 14Dissolve in the irrigation waterHigh percentage, quick effect Very economical!No long-term effect
Mixed fertilizer, organic-mineral Complete fertilizer3 – 6 weeksGranules, partly water-soluble and microbiologicalEasy to useLow nutritional values
Organic fertilizer Complete fertilizer or single-nutrient fertilizer3 – 30 weeksMicroorganisms convert the substance into plant-available nutrients.Simple application, low salt contentIncorporate, low nutritional values.
Vegan fertilizers Mostly complete fertilizers2 – 12 weeksMicroorganisms convert the substance into plant-available nutrients.No salt damage, low Co2 loadIncorporate, low nutritional values.
Bio-stimulants 1 – 3 different componentsUp to one yearSoil fungi and bacteria that occupy niches and form symbiosesWithout chemical additivesSome highly effective substances
Soil – additives Mostly one substance6 – 18 monthsWater reservoir, air reservoir, loosening upIs helpful for soil improvementMany different substances are available
Lime (PH value increase)


6 – 8 monthsWater-soluble, powder or granulesImproves soil lifeImportant cell building block! Indispensable for acidic soils!
Trace elements,
Micronutrients such as: Mg, Fe, Cu, B, Mn, Mo, Zn
3 – 6 months
in most
Contains complete fertilizers
Water-soluble powder
or liquid
Improves leaf coloration, assimilation and many important processesIndispensable cell building blocks


I have deliberately refrained from naming individual preparations here, because everyone prefers a favorite fertilizer that is used. Rose fertilizer, perennial fertilizer, flower fertilizer or tree fertilizer can be used. You can get them in garden centers, country stores, DIY stores, nurseries or discount stores.

When fertilizing clematis, it is important to use a dosage that is adapted to the plant’s development!

The manufacturer’s instructions must be strictly adhered to, because a lot does not help a lot!

Complete fertilizer

Complete fertilizers (NPK), as the name suggests, contain all the main nutrients and trace elements! The various types of fertilizer differ in their composition, sometimes significantly. The higher the numbers, the higher the fertilizer yield!

Example: NPK stands for: N = Nitrogenium Nitrogen, P = Phosphorus, K = Potassium. The letters are accompanied by numbers that indicate the percentage of the individual nutrients.

After prolonged rainfall, it makes sense to top up with a single-nutrient fertilizer, as N = nitrogen and Ca = lime in particular are quickly washed out and are no longer available to the plants. Yellowing is the result and increases rapidly.

A very popular, pure nitrogen fertilizer is horn shavings. It can take several months before the desired fertilizing effect is achieved, as soil organisms must first convert the substance and make it available to plants. This depends particularly on the temperature and humidity. The misconception that horn shavings alone are sufficient as a fertilizer is clearly answered at this point with “no is not enough”.

Organic fertilizer

An important note on the popular organic fertilizers. Most of these fertilizers come from factory farming. (horn meal, horn shavings, bone meal, guano, etc.) For example, the use of sheep’s wool as a fertilizer is new. Vegan fertilizers are becoming increasingly important. The use of green manure (alfalfa and legumes) should not be ignored either.

This contrasts with today’s high-tech fertilizers, which are becoming ever more sophisticated and efficient, also in terms of environmental compatibility and groundwater protection.