Go with the flow
When homes are designed and built, measures are taken to divert rainwater away from the house and off the property. Structural changes on the property or in the surrounding environment may cause changes to volume and flow of water entering a property and very often require modifications to the initial drainage design.
The garden featured in this issue is in a residential estate in Centurion, Pretoria. The house is built on a slope with the front door positioned slightly lower 200m2 front garden that is open to the street. The house was incident-free until it experienced a flooding incident.
The garden before
A few months prior to the event, a speed hump had been constructed on the road adjacent to the property. This helped to calm the vehicle traffic but obstructs the flow of rainwater. In a heavy downpour, water diverts onto the property. The front garden was mainly lawn, so the rain water merely washed down the slope and pooled against the house. When seepage into the soil simply wasn’t fast enough, the water entered the house, causing extensive damage.
A drainage collection point was installed in the lowest point of the garden to capture and divert water from the front door. Realising that the garden needed a facelift, we were asked to redesign a low-maintenance, water-wise solution that considered the possibility of the occasional flow of water through the garden.
The garden was originally planted by the homeowners over several years and contained an eclectic selection of plants which were probably selected based on trends at the times of purchase. This resulted in the space lacking a synchronous theme with a combination of tropical plants, desert species and forest species. Some of the variety included a queen palm (Syagrus romanzoffiana), a pair of ponytail palms (Beaucarnea recurvata), a pencil conifer (Juniperus scopulorum ‘Skyrocket’), a sago palm (Cycas revoluta), a New Zealand cabbage tree (Cordyline australis) and a row of potato bush standards (Solanum Rantonetti). There were no groundcovers and this collection of plants provided very little to attract any local wildlife to the garden.
Our first decision was to remove the lawn which requires lots of water and is high-maintenance (mowing, fertilising and seasonal treatments). We created a stony dry river-bed to channel water from the road towards the drainage point. The slope was broken with contours to help slow the flow of water and direct it to the catchment area. A stepping stone path winds through the garden toward the tap and allows one to experience the wonders of the garden. The plants were selected to provide interest to fit into the goal of creating a miniature bushveld river scene. Height, screening and bird perches are provided by trees – Kiggelaria africana (Wild Peach), Heteropyxis natalensis (Lavender tree), Halleria lucida (Tree fuchsia) and a Senegalia galpinii (Monkey thorn).
We included lower-growing, spreading groundcovers like Arctotis stoechadifolia (African daisy), Aptenia cordifolia (Aptenia), Plectranthus madagascariensis (Variegated plectranthus) and Cotula sericea (Silky Cotula) along points of the path and river course.
To cater for seed-eating birds, we planted grasses like Chlorophytum saundersiae (Weeping anthericum), Juncus effuses (Common rush) and Aristida junciformis (Ngongoni three-awn). These grasses look magnificent when blowing in a breeze and require minimal maintenance. Nectar-feeding birds like sunbirds can feast on the Leonotis leonorus (Wild dagga), Strelitiza reginae (Crane flower), Halleria lucida (Tree fuchsia) and three aloe species that flower at different times of the year.
The garden just after planting
The garden is still young and evolving, but the last three years has seen it teeming with life. It has become home to several of species of bees, butterflies and spiders. Being a mere 1km from the Zwartkops Resort which is a large undeveloped area along the Hennops River, the garden has attracted numerous birds. This practical drainage solution has become a feature with at least one plant species in flower at any time of the year. Hopefully, it will set a trend for the estate as passers-by who watched the transition recently commented that they were sceptical at first but now see the vision of this lawn-free indigenous garden.
The garden one year later
The garden one year later