MONTANE SOUTH AFRICAN GRASSLANDS AS A NEW PLANTING DESIGN FORM IN URBAN GREENSPACE

The aims of this study were to develop communities of South African montane grassland species as a new planting design form in urban parks and green spaces. The uniqueness on the canopy texture and structure additionally the attractiveness produced from colorful flowers, from spring, summer and autumn potentially give strong design impact. To develop the community for use in urban greenspace three series of experiment were conducted to investigate time of sowing, growth performance, winter hardiness, competition in communities and appearance. Most of the species show good emergence and growth performance when sowing seeds directly in the field between March and May. Pre-germination treatments did speed up germination post sowing in the field but do not result in a significant increase of emergence percentage compared sown directly. Studies on species hardiness during extreme cold winter in 2010/2011 on different types and depth of media (sand 70 mm, sand 140 mm and soil 70 mm) found that increase in depth of mulch decrease the survival of the species on sand. Increased seedling mortality was due to lower root zone temperatures in the deeper sand with ambient temperatures as low as -8.7 °C. Most of the species sown in soil shows a better survival than sown in sand. Greater soil wetness in soil was less hostile to overwintering survival than was the lower temperatures associated with the sand treatments. Evergreen species such as Dierama robustum, Berkheya multijuga, and Senecio macrospermus overwintered well and Gladiolus saundersii is one of the hardiest species in this experiment. In the competition experiment, forbs species were the most productive in producing biomass and % cover in every community. Berkheya purpurea is a highly productive species and dominant in the first and second year of this study and greatly affected the production of biomass and canopy coverage in the communities it was present in. The communities with forbs species in combination produced 50% cover faster approximately 50 days after spring cutting in the second year. The geophytes species had much less influence on the biomass and % cover in the community, at least in the first two years. Even though Kniphofia uvaria also able to produce high biomass but does not greatly increases % cover due to the canopy structure being more open. However, the combination of species with different canopy layers is a very effective spatial arrangement for naturalistic design. High germination percentage as well as good growth in the first and second years of study showed that most species are able to survive and flower well in the UK. Most of forbs from low canopy species flower early in the season on the first and second years while geophytes species with slow growth, medium and tall canopy flowering from mid-season until a late season. Based on the results of these studies it appears that South African montane grassland have good potential to be used as a new planting design in UK urban greenspace