Influence of miscanthus-based growing media with the amendment of hydrogel and different multicomponent fertilizers on the fresh biomass of Hydrangea arborescens 'Annabelle'

Increasing demand for good quality nursery stock produced in accordance with resource-saving technology has sparked research efforts to find new solutions for ornamental cultivation. Particular attention is paid to water-saving methods, such as hydrogels, as well as peat substrate replacement due to the tightened peatland protection. The aim of this research was to assess the influence of substrates based on miscanthus straw with hydrogel amendment and two multicomponent fertilizer types on the fresh weight of Hydrangea arborescens 'Annabelle'. The first factor was type of substrate composed of peat (P) and shredded miscanthus straw (M) in volume ratios: 100P, 70P:30M, 50P:50M, 30P:70M and 100M. The second factor was the use of hydrogel - its presence (H) or absence (WH). For the third factor the following fertilizers were used: 3 g BasacotePlus 3M (B) and 3 g+3×1 g YaraMila Complex (YM). The highest fresh shoot, root, and total weight was produced by the plants grown in 100P. Hydrogel (H) amendment increased the root fresh weight, while fresh shoot weight was higher in plants without its use (WH). A higher fresh root and total weight was produced by plants fertilized with Basacote (B), while shoot fresh weight was higher under the YaraMila treatment (YM). There were also some significant interactions observed on the tested biomass features. The highest shoot weight and total weight was noted in 100P × WH and in 100P × YM. The interaction of all three tested factors that resulted in the highest fresh weight of shoot and total weight was 100P × WH × YM, while for fresh root biomass accumulation the most beneficial was 50P:50M × H × B. Miscanthus straw should be considered as a potential substrate, but more research is needed to understand the relation between miscanthus straw and other amendments.