The response of pelargonium to different growing media and liquid fertilizers - an experimental comparison
In the UK, the drive to improve the sustainability of horticultural practice continues to diversify the range of materials used as growing media. Most gardeners and growers assume fertilizer products will perform similarly when combined with different growing media. We investigated the effect of two liquid fertilizer products on the quality of Pelargonium 'Maverick red' in four proprietary growing media mixes (based on coir, green compost, peat and wood fibre). Plants were subjected to three fertilizer treatments; unfertilized, fertilized with an inorganic liquid fertilizer (containing soluble N forms), and fertilized with an organic liquid fertilizer (containing urea and more complex N forms). Plant quality was assessed after 18 weeks by measuring dry shoot biomass, plant growth index and visual quality. Whilst plants grown in green compost- and wood fibre-based media tended to be of marketable quality regardless of fertiliser type applied, peat and coir grown plants were much poorer on all three quality criteria when the organic fertilizer was applied. As the effectiveness of one of the liquid fertilizer products depended very much on the type of growing medium in use, it is clear that gardeners and growers need to carefully consider their choice of growing media and fertilizer combinations. This will only be possible if manufacturers provide more detailed information about the content and usage of their products.
Barrett, G., Alexander, P.D., Nevison, I., Robinson, S. and Bragg, N.C. 2017. The response of pelargonium to different growing media and liquid fertilizers - an experimental comparison. Acta Hort. (ISHS) 1168:161-166
sustainability, coir, green compost, wood fibre, peat