With site development as a major part of any building construction, landscape design enhances the beauty of the site. It is a balance between the softscape and the hardscape. As much as the hardscape is important functionally, the softscape brings the aesthetic value to the design with colours and textures. A landscape expert, Dr Aseem Gokarn Harwansh explains the importance of horticulture in landscape design.
Dr Aseem Gokarn Harwansh
My tryst with horticulture started as a young girl visiting our farm on the outskirts of Mumbai, harbouring one of the first Private Plant tissue culture laboratories of Maharashtra, way back in early 80’s with a licensed nursery of fruit plants, roses and other ornamentals. Researching on newer varieties, experimenting with grafting of plants, hybridisation techniques became an avid passion. Use of mist house, drip irrigation, micro sprinklers, bunding, mulching and water conservation techniques was a routine. Intercropping, dense plantation per square meter for maximising yield, use of less laborious techniques, emphasising organic/natural approaches came naturally under the circumstances. Unknowingly I saw myself practicing “Biodynamic Horticulture”, that ‘farms’ or develops the soil, uses macro and micro organisms, selects plants to adapt to microzones, topographical contours, Cover cropping, companion cropping: amalgamation of sustainable techniques. And so started my journey of using these principles in the landscapes that we design!
Use of ornamental horticulture to complement aesthetics of a landscape is passé: its capabilities to curb heat mitigation, capture dust, VOCs, Create buffer zones, Phytoremedation, Stabilising ecosystems, water conservation, etc. needs to be explored more.
While designing Asia’s largest automobile factory, Mahindra Vehicles Manufacturers Ltd, our major concern was to improve soil conditions as most of the land mass was cut and filled hard rock. We moved the top virgin soil, and backfilled it after achieving required depth, added supplements like Trichoderma to combat soil pathogens, Rhizobium cultures and vermicompost to stabilise and improve soil fertility. The land was devoid of much plantation and heat was our major adversary. We used soil bunds to trap water, mulching, trench planting techniques, companion planting; today the place looks like a green haven. Innovative techniques like subsurface irrigation, use of xeriscapic plants like Euphorbias, Phoenix Palms, furnished us extra credits during IGBC Assessment.
We advocate grass pavers in parking lots that curb their heat island effect. Choice of right grass species aids in washing away of VOCs and other harmful pollutants besides lowering the temperature and increasing ground water permeability.
Lake edges strengthened by RCC walls denude the riparian ecosystem and wash away harmful pollutants in water bodies. We propose stone pitching or use of soil erosion blankets or geocells often planted with groundcovers whose roots allow phytoremedation and stop soil erosion or scouring. Thus, the water holding pond at Nerul, ‘The Jewel of Navi Mumbai’ has a green edging on its bank which also oxygenates the water that runs over it into the pond. Vetiver grass is suggested at the river banks of Godavari at Nashik which will not only stop soil erosion but whose roots emits a faint fragrance when dried and submerged in water.
While designing for the JKTDC, we have converted water stagnating areas into water reservoirs edged with bioswales for stabilising riparian zones. In such temperate zones, use of bulbous plants or annuals and biennials can create interesting vistas throughout the year.
Urban landscapes are interspersed with road medians, public gardens, play grounds, traffic islands, and pedestrian walkways. A few lakes or water bodies offer promenades and interactive opportunities.
We design road medians with a 3-4 tier plantation, where a ground cover acts as a live mulch, conserving moisture, plant edges or low hedges absorb VOCs emitted from the moving vehicles, A flowering shrubline adds the aesthetic component as it is in the line of vision of the passengers and a dwarf or tall tree creates the required canopy. Use of shallow rooted plants like Palm trees, Caryota urens, Roystonia regia or Date palms creates a good avenue. One must avoid widespread palms like Bismarckia nobilis as these would obstruct the vision. The beauty of foxtail palms is accentuated in cluster planting.
As a consultant with the Atal Mission of Restoration and Urban Transformation, we have used several indigenous species like Cassia fistula, Lagerstromia floss reginae for their array of flowers, fragrant species like Millingtonia hortensis, Mimusops ellengi, and also attempted to create urban forests in pockets with mixed plantation of flame of the forest, herda, behda, kailashpati, Bael . One must explore the rich flora available to us and make it available to the common public. Hence, we have successfully created The Healing Tree Groves, Sanskriti Udyan, Nakshatra Parks, Saptarangi Udyans, in cities. We have incorporated a concept of creating AMRUTVANS in city spaces which have fruits and nectar producing plants so that butterflies, birds all find a home, complete a food cycle and form vibrant ecosystems.
In our attempt to design interactive children parks, we often use plant species that store water in their buds, which when pressed, spurge out like micro sprays, plant leaves that close on touch, flowering plants that leave their colour trail on our hands. We must use such nature play in our landscapes. Defined texture trails, fragrant trails, and colour trails by using specific plants make the spaces more interesting and is our forte.
Microzones can be created by using right trees judiciously, screening by planting trees closer than their normal distance allows them to grow taller, use of creepers or climbers on screens can also create micro pockets. Fragrant climbers like Quisqualis indica, Clematis ligusticifolia, Cestrum nocturnum act as air purifiers. Intercropping annuals and biennials amongst taller trees can utilise the space and offer vibrant colour.
Podium landscapes often have raised planters. Softening the planter walls by creepers like Vernonia, wadelia, trilobata can cool the temperature and also act as protection to children running around the podium. Lantanas, Allamandas can attract butterflies.(The Address at Ghatkopar, Wadhwa Group) We often design subsurface water tanks or control rooms masking them with climbers and ground covers or green roofs. (Proposed Goda Park at Nashik). Shaded spots around swimming pools often planted by evergreen trees like Alstonia scholaris can give solace to kids and senior citizens.
Thus, horticulture is an integral part of landscapes and its creative expression can create seemingly disconnected spaces into seamless interactive zones.