Plant strengthening products (plant strengtheners, soil additives, plant aids, biostimulants) are used to improve nutrient supply and overall plant health. This year, eight research stations are testing various strategies in a ring trial in collaboration with consultants and commercial companies for plant strengthening products on Myosotis sylvatica ‘Mon Ami’. The results of the trial will be presented at the IPM.

At the LLH experimental farm in Geisenheim, a plant fortifier 2025 in combination with a peat-free substrate showed a surprisingly strong effect. However, such effects are not guaranteed and usually only occur when there are problems in the cultivation system, such as trace nutrient deficiencies, suboptimal water supply, or pH fluctuations. In such cases, the use of plant fortifiers can reduce production risk.

At the Rheinpfalz Regional Service Center, plant fortifiers are being tested in various crops to address a range of issues. The experiment shown here is testing whether regular use of plant fortifiers can help keep mother plants healthy over a longer period of time. It's also looking at any effects on the cuttings taken in terms of health (botrytis, root diseases) and the length of the rooting phase.

In vitro cultures ensure healthy elite material for vegetative propagation systems. The BioVitro project uses only organic inputs for media preparation. The sterile culture media are largely free of nitrate and ammonium, so the plants are supplied with nitrogen directly via amino acids. The research project is investigating the formative effects of this alternative nutrition on further cultivation under organic greenhouse conditions.

The Bavarian State Institute for Viticulture and Horticulture is conducting the “MoKuBioJp” project to investigate the extent to which compact, highquality young plants of organic quality can be produced using a suitable LED lighting strategy. With the help of the controllable light spectrum of LEDs, the elongation growth of the plants is to be reduced in order to reduce or replace the use of chemical growth regulators.

Plant fortifiers, biostimulants, plant or soil additives, and other “alternative products” promise many benefits: from increased stress tolerance, improved nutrient uptake, and optimized growth to reduced susceptibility to pathogens. They are considered particularly user-friendly and environmentally friendly. Many of these products are based on different microorganisms, some of which have plant growth-promoting properties.

To answer the question of whether various alternative products have an influence on the root growth of Calluna cuttings, a total of 17 different variants were tested at the Teaching and Research Institute for Horticulture in Bad Zwischenahn.

The use of chemical pesticides is increasingly viewed critically. In order to develop alternatives, the State School of Horticultural in Stuttgart-Hohenheim is investigating the use of carnivorous plants in ornamental plant production. The aim is to test their effectiveness against pests and to develop cultivation guidelines – from fertilization and irrigation to propagation and optimal conditions of use. The project was triggered by the practical experience of an ornamental plant nursery and the expertise of a carnivorous plant specialist. The results could show how carnivorous plants can be integrated into cultivation processes in a sustainable and practical way in order to significantly reduce the use of insecticides.

Strong plants need an optimal supply of nutrients. The Hanover-Ahlem Teaching and Research Institute of the Lower Saxony Chamber of Agriculture uses various nutrient deficiency symptoms in different plant species to show what happens when this is not guaranteed.

Numerous crops can be grown using reduced peat or even peat-free substrates. However, “peat-free” does not necessarily mean “completely peat-free.” Every substrate supplier has its own individual ingredients from which the substrates are produced. This results in very different physical and chemical properties, which must be taken into account in cultivation. At the Horticultural Research Center in Straelen, poinsettias were cultivated in six different peat-free substrates in 2024 and 2025. Important key points from practical experience will be presented in the 2026 educational exhibition.

As peat is increasingly being phased out, the challenges in pot plant cultivation are growing – from production and transport to marketing and the end consumer. This is where the TerZ 100 project comes in. In five model regions across Germany, ornamental plant growers are being supported in their transition to largely peat-free production, and specific issues related to peat reduction are being examined. One of these questions is: Does the use of peat-free substrates also have an impact on the shelf life of ornamental plants along the marketing chain? To answer this question, CC containers with plants produced using peat-free and peat-based substrates are equipped with sensors and monitored throughout the marketing chain. The corresponding technology, including live measurement, will be on display at IPM by the Chambers of Agriculture of North Rhine-Westphalia and Lower Saxony.

The FiniTo project (“Specialist information for horticultural businesses on switching to peat-free and peat-reduced growing media”) offers comprehensive, nationwide support for all sectors of commercial horticulture on the topic of peat reduction. Switching to peat-reduced or peat-free substrates requires specific adjustments to cultivation practices. At the educational exhibition, FiniTo provides specific advice and practical tips on how to achieve this. Particular attention is paid to the quality of irrigation water and the effect of pH on nutrient availability for plants.