Peatlands serve as unique ecosystems rich in carbon, distributed in almost all countries on the planet and as such represent the largest carbon reservoirs on land. The formation of peat is related to the accumulation of organic matter under anaerobic conditions, which makes these habitats one of the most sensitive ecosystems to climate change. Such ecosystems are an important factor for mitigating natural disasters, filtering and storing water. At the same time, peat forms a substrate with suitable physical and chemical characteristics, which is the main reason for its use as a traditional growing substrate in nursery production. The consequences of the degradation of peat ecosystems and climate change indicate that finding sustainable solutions for peat use in horticulture is of global importance for the preservation of the biodiversity of such habitats. The aim of this research is to fi nd a substrate that would successfully replace the use of peat in the production of Hydrangea macrophylla and contribute to the development of sustainable nursery production. In landscape architecture, large-leaved hydrangea is used for ornamental purposes, but it has great potential for soil remediation and is adaptable to abiotic conditions. This research was conducted in the nursery of the Faculty of Forestry, and it consisted of 9 treatments of Hydrangea macrophylla species. Alternative substrates 2 (peat 30%, pine bark 50%, humus 10%, vermicompost 10%) and 3 (compost 50%, pine bark 30%, sand 10%, vermiculite 10%) proved to be the best substitute for peat, although deficiencies in root system development were noted. The result indicates the possibility of obtaining an ecologically acceptable solution for growing hydrangea, which is extremely important for reducing the use of peat in horticulture and preserving wetland habitats in the region.

Commercial production of sweet cherries is possible up to approximately 60° N latitude in Norway and is among the most economically important fruit crops in the country. The harvest is late, but yields are very high, and the fruit is intended solely for the fresh market. The objective of this study was to assess whether sweet cherry can be grown in pots and to determine fruit quality (sugar, acid, polyphenol, and mineral content) of three sweet cherry cultivars (‘Van’, ‘Lapins’, and ‘Regina’) grown in high tunnels with varying levels of fertigation (F) and the application of slow-release (SR) fertilisers. Trees were planted in 35 L plastic bags, trained as spindle trees, with a spacing of 1 × 2.5 m (4000 trees/ha). The tunnel was covered with polythene from flowering until harvest. Fruit produced in pots had low levels of sugars and acids and high levels of phenolic acids and flavonoids, while the mineral content depended on treatment and cultivar. The main sugar components (glucose and fructose), the sweetness index, phenolic acids (chlorogenic acid and ferulic acid), flavanols (catechin, rutin, quercetin, and hyperoside), and minerals (P, K, Mg, Ca, and Na) were much higher in the F treatment. SR treatments were more effective in increasing the content of acids (shikimic, malic, and quinic) and total phenolic content (TPC). Radical scavenging activity (RSA) and total sugars showed no statistically significant differences between the treatments studied. ‘Lapins’ fruit obtained from the fertigation regimes (when Kristalon brown + Calcinit + Magnesium-sulphate were added from mid-April to 1 September and plain water for the rest of the season, up to an electric conductivity (EC) of 0.5 and 1.0) contained the highest levels of minerals (P, K, Mg, Ca). The ‘Van’ cultivar from F treatments, especially VF2 (when Kristalon brown + Calcinit + Magnesium-sulphate were added from mid-April to 1 September and plain water for the rest of the season, with EC 1.0) and VF3 (when Kristalon brown is added in July, Kristalon brown + Calcinit + Magnesium-sulphate in August, and plain water for the rest of the season) had the highest sweetness index, glucose, fructose, chlorogenic acid, ferulic acid, and hyperoside in sweet cherry fruit. ‘Regina’ under the RSR1 (50 g Multicote and 30 g chalk lime per tree) and RSR2 regimes (100 g Multicote and 30 g chalk lime per tree) produced fruit with the highest acid components, RSA and TPC. This suggests that sweet cherry trees can be grown in pots under high tunnels, but nutrition should be adjusted for each cultivar according to its physiological responses to specific microclimate conditions.