Beschreibung:
<jats:p>Three ornamental species (<jats:italic>Spiraea japonica</jats:italic> `Little Princess', <jats:italic>Physocarpus opulifolius</jats:italic> `Nanus', and <jats:italic>Prunus</jats:italic> × <jats:italic>cistena</jats:italic>) were potted in seven different substrates. The control substrate contained peatmoss, composted conifer bark, and fine crushed gravel (5:4:1, by volume). In the other six substrates, peatmoss was partially or completely substituted by different proportions of three organic residues (10% or 50% of the mixture made up of fresh bio-filters, 5% or 10% in composted sewage sludges, and 10% or 40% in composted deinking sludges). Four fertilization regimes (0, 200, 400, and 600 mg N/liter in the form of soluble fertilizer 20–20–20) were applied weekly onto containers. The experimental design was a split-plot with six replications. Physical and chemical analysis of the organic residues proved that the composted sewage sludges were richer in minerals than the other residues. Moreover, fresh bio-filters and composted deinking sludges were less granular than composted sewage sludges. The 10% proportion of each organic residue, combined with the other materials, was the most-adequate proportion and did not reduce the growth of plants (height, aerial and root dry matter). In addition, a dose of 400 mg·liter<jats:sup>–1</jats:sup> generally gave good results, especially for fresh bio-filters and for composted sewage sludges. However, it is preferable to use a higher dose (600 mg·liter<jats:sup>–1</jats:sup> if composted deinking sludges are used.</jats:p>