African Wildlife & Environment Issue 83

WATER WISE

HYDROZONING

Veggie gardens, roofs, and social upliftment

A hydrozone in a landscape refers to each section of the landscape that is watered using the same valve i.e. the hydrozone (hydrostation) in question is watered as a unit. Hence, each area in a landscape or garden that is individually watered must be assessed separately Zone into high/medium/ low/very low water use areas

P roducing fresh, organic and healthy food does not need to be restricted by a lack of space. Unfortunately, a lack of space is a dilemma faced by many as the popularity of townhouses, flats and apartments grows. However, a lack of space should not stop the privileges of gardening - just ‘look up’ and encourage your clients to consider rooftop gardening. Growing ‘green roofs’, or edible rooftop gardens, is a fairly new concept that is taking the world by storm. As the amount of space available per person decreases and the price of food increases, more and more people are looking at investing in home food gardens. Besides the benefit of reduced costs and a sustainable supply of food, home grown fruit and veggies are healthier and kinder on the environment than their mass-produced counterparts. While growing a food garden on your roof may be tricky, remember these steps when considering rooftop gardens: ─ Be sure the roof can take the extra weight of the soil needed for the garden - perhaps consult a structural engineer before starting. ─ An additional protective layer will need to be placed over your existing roof unless trays are being used to grow vegetables in. ─ Make sure there is adequate drainage from the roof garden to prevent the accumulation of water

and potential damage to the roof. ─ Take note of the pitch of the roof - a slope that is too steep may cause plants to slip off, while a roof that is too flat may cause excess water to pool. ─ Observe the aspect of the roof, regional climate of the area, and wind and shade in order to position the right plants in the right place. ─ Remember that the weather conditions on the roof may be extreme, so choose plants that are able to survive and grow well in very hot, and possibly dry and windy conditions. Tomatoes, cabbage, spinach, lettuce, green peppers, spring onion, eggplants, amadumbe and chillies can be grown successfully on roofs. ─ In areas of excessive wind, an artistically placed shade cloth or trellis could add an interesting feature to the rooftop. Rooftop veggie gardens can be incorporated into social upliftment or employee well-being programmes at the office. Perhaps a successful rooftop garden can be used to supplement the office canteen requirements? The benefits of being able to harvest organic food, sustainably and with no threat to our environment,

HIGH ZONE • This should be no more than 10 - 30% of the landscape. • Plant water-loving annuals/plants in selected high water use areas e.g. entrances, entertainment areas, containers and focal points. • Avoid long winding borders of colour - impractical to water. • Use colour in containers. MEDIUM ZONE • This should make up between 20% and 40% of the landscape. • Can incorprate the bulk of the garden or landscape. • Consists mainly of shrubs, perennials, ground cover and lawn. LOW ZONE • Makes up between 30% and 60% of the landscape. • Is the backbone of the design. • Is mainly trees, large shrubs, limited small Mediterranean type shrubs, succulents and aloes.

VERY LOW ZONE • This should make up between 40% and 100% of the landscape. • Consists of mainly locally indigenous trees, shrubs and other plants. • Permeable paving rather than solid non permeable paving should be used in this zone. The proportions of landscapes or gardens allocated to each zone is based on the principle that sites should be landscaped by considering certain maximum areas of the site allocated to different hydrozones. This is used merely as a guide; however, it is believed that because South Africa is a water stressed country that the areas allocated to high hydrozones should be minimal.

If a landscape doesn’t have high and/or medium hydrozones then a greater area should be allocated to other lower water hydrozones.

are considerable. Also, roof gardens use rainwater and in doing so prevent excessive stormwater run-off, making them Water Wise too!

www.randwater.co.za and click on the Water Wise logo FOR FURTHER INFORMATION ON WATER WISE, PLEASE CONTACT US ON: 0860 10 10 60

www.randwater.co.za and click on the Water Wise logo FOR FURTHER INFORMATION ON WATER WISE, PLEASE CONTACT US ON: 0860 10 10 60

60 | African Wildlife & Environment | Issue 83 (2023)

61 | African Wildlife & Environment | Issue 83 (2023)