Articles
ANNUALS AND SEDUM-CUTTINGS IN SEED-MIXTURES FOR EXTENSIVE ROOF GARDENS
Article number
643_39
Pages
301 – 303
Language
English
Abstract
In March 1999 five seed-mixtures were sown on a shallow substrate bed on a roof near Bernburg.
The aim was to study the effect of adding annuals, or cuttings of several sedum-species, respectively, instead of the usual high percentage of grass-seeds, in order to optimise the coverage and density, even without a high amount of grasses in the first and second year after sowing.
A second factor involved two different fertilisers.
Only on fertilized plots in the second year was a covering rate
> 60% achieved.
The influence of fertilizer in the second year was substantially larger than the effect of the seed-mixtures.
Suitable annuals were Gypsophila elegans, Iberis amara, Silene armeria and Xeranthemum annuum, which were able to form aspects in the first year.
Gypsophila elegans provided a stable population in the second year.
Even without increasing the coverage significantly, it is highly recommended as an addition to seed mixtures because of its flowering aspect.
The trial confirms the importance of fertilisation on shallow-substrate roof-gardens.
Cuttings of Sedum album, S. sexangulare and S. reflexum can reach high coverage relatively fast, but on larger areas involve higher costs.
Even a relatively low addition of 10 g/m² Sedum to seed mix can result in a significant effect and reduce the proportion of grasses, if fertilised even in the first vegetation period after sowing.
The aim was to study the effect of adding annuals, or cuttings of several sedum-species, respectively, instead of the usual high percentage of grass-seeds, in order to optimise the coverage and density, even without a high amount of grasses in the first and second year after sowing.
A second factor involved two different fertilisers.
Only on fertilized plots in the second year was a covering rate
> 60% achieved.
The influence of fertilizer in the second year was substantially larger than the effect of the seed-mixtures.
Suitable annuals were Gypsophila elegans, Iberis amara, Silene armeria and Xeranthemum annuum, which were able to form aspects in the first year.
Gypsophila elegans provided a stable population in the second year.
Even without increasing the coverage significantly, it is highly recommended as an addition to seed mixtures because of its flowering aspect.
The trial confirms the importance of fertilisation on shallow-substrate roof-gardens.
Cuttings of Sedum album, S. sexangulare and S. reflexum can reach high coverage relatively fast, but on larger areas involve higher costs.
Even a relatively low addition of 10 g/m² Sedum to seed mix can result in a significant effect and reduce the proportion of grasses, if fertilised even in the first vegetation period after sowing.
Publication
Authors
W. Kircher
Keywords
Sedum species, cuttings, grasses, forbs, seed-mixtures, roof gardens
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