John Richardson Gardens   Garden Design and Construction

Practical tips for Waterwise gardening

Plant selection
Of all the water saving methods, plant selection is one of the most effective methods for saving water in the garden. Traditional European style plantings are going to cost you dearly for the water and one need only look at the mountainside to know that there are a great many plants that grow happily without being fussed over with hosepipes, irrigation systems and alike. I have often being tempted to counter the adverts of bore-hole drilling companies with my own, somewhat cheeky, advert. Something along the lines of 'Why pay R80 000 for a hole in the ground when you can have a whole indigenous garden for half the price?' Of course, I never did bother, mostly because I have friends who own drilling companies; but also because boreholes are in fact very useful for big gardens, estates, golf courses, farms and alike, but for the average house in the suburbs….. they're just not feasible.

My point is that the absence of a borehole is no reason to forgo a stunning garden. With careful garden design and using plants from the winter rainfall area, one can easily achieve a water conservative garden without the need to splash out on a very deep and costly bore-hole. (Note that I am not referring to well-points here, which are a lot less costly and if you can find water so shallow, then you're very lucky. Be nice and give some to your neighbors!)

Know your space
If you are not using a landscaper or horticultural consultant it is sensible to do your own research before dashing off to the garden center with your hard-earned cash. You should know what type of soil you have (sand or clay or loam) wind patterns and how much water you have available. If the salesperson hasn't been to your site and you don't know much about plants then you're playing horticultural pin-the-tale-on-the-donkey. Plant knowledge is the most hard-won knowledge there is when it comes to gardening, as so much of it is trail and error. The more information you have the better your chances of success.

Use a consultant
Using a professional consultant will save you a lot of heartache in both the short and long term. Gardening is often perceived as a simple activity with very little consequence of failure. And while this is only partly true it will definitely change as water becomes more costly and the traditional process of trial-and-error becomes less attractive. A professional person who is familiar with your site should be able to get it right the first time, thereby maximizing the return on your investment. There are a lot of businesses out there offering a wide range of services from consultation only - right through to everything under the sun, so choose wisely.

Plants that are water-wise include the following: 

Brachylaena discolor
Tarchonanthus camphoratus
Dodonaea viscosa 
Rhus crenata
Rhus lancea
Rhus lucida
Diospyros whyteana
Chrysanthemoides incana
Chrysanthemoides monilifera
Dovyalis caffra
Leonotis leonurus
Eumorphia prostrata
Grewia occidentalis
Buddleja saligna
Euryops pectinatus
Euryops virgineus
Helichrysum cymosum
Helichrysum petiolare
Coleonema pulchrum
Barleria obtusa
Olea europaea subsp. africana
Senecio macroglossus
Metalasia muricata
Carissa macrocarpa 'Green carpet'
Chondropetalum tectorum
Chondropetalum tectorum 'Fishoek '
Elegia cuspidata
Thamnochortus cinereus
Thamnochortus insignis
Dietes grandiflora
Aristidia junciformis
Aloe sp.

Note that this list is not comprehensive, and it is limited to plants that are generally readily available and have a proven track record for landscaping. There are a great many other water-wise plants out there and you will have to make your own inquires at the garden center. 

Wind pulls water out of plants by a process called evapo-transporation. How it works is not important, but you should know that the more wind the greater the drying effect. And in case you hadn't noticed: summer in Cape Town is like… ten on the Richter scale (the wind one) ….which is awesome if you’re a kite-surfer but not so great if you’re like gardening with straight-up growing trees. 

The best way to reduce the effect of the wind is to create wind-breaks using plants or fences, or a combination of the two. Solid walls are not so great because they create pressure gradients in the air causing it to swirl erratically, which is unpleasant and counter-productive. The most effective wind-breaks are large evergreen shrubs that have leaves from the ground up and flourish regardless of being planted in a wind tunnel. The deeper and more layered the planting, the greater the calming effect. For ease of maintenance it is often better to plant fewer species, rather than multiple different species that require varied maintenance at different times of the year. If space is an issue then a single species hedge usually suffices. My favorite wind break plant is Rhus crenata. Its' mid-green colour and medium texture allows it to be used with many different types of garden and it grows easily in most soils. 

Other plants that are great for wind breaks include:

Brachylaena discolor (allow it to grow multiple, bracing stems)
Tarchonanthus camphoratus (this will give height)
Rhus crenata
Chrysanthemoides monilifera
Dovyalis caffra
Sideroxylon inerme
Dodonaea angustifolia
Syzygium cordatum
Grewia occidentalis
Dodonaea viscosa 

There are many other plant species that will do the trick but, in Cape Town, in the teeth of the south-easter, the indigenous options are few and far between. In fact very few trees grow naturally on the Cape Flats. Non-indigenous options are plentiful but this article is about indigenous planting.

Hard landscape elements.

There are a few techniques that can be applied to laying out a garden that can go a long way towards maximizing the return of every liter of the stuff pouring out the end of the hosepipe. These are both general and specific things that accumulatively will help.

Terracing simply means creating level areas which reduce run-off. Terraces normally conjure up ideas of large leveled areas of lawn and bedding in formal gardens. This need not be the case and if one works with the natural contours of the land to create level areas, it allows the water to pool and soak in, rather than runoff and be wasted. Even creating little 'dams' around your plants on a slope it will go some way towards keeping the water were it is needed instead of at the bottom of the garden.

Not only do edges give the garden a sharp, well-organized feeling, they also go someway towards slowing the water down and allowing it to soak in where it was dropped. Edges can be constructed from any number of materials including bricks, cobbles, timber, plastics and a whole lot more.

Hard-standing areas
Paving or other hard-standing materials like gravel, concrete, paving bricks, flagstones, timber-decking, etc obviously do not need to be watered and therefore make for very water-wise gardens. Also run-off from these areas can be directed towards beds and planted areas, thereby maximizing the use of rainwater and water that is used for 'washing down the decks' occasionally.

From an aesthetic point of view, be careful not to overdo it either with too much variety in your hard surfaces, or too much of one particular type of hard surface. This can be overwhelming and leave the garden feeling unsettled or unfriendly. Consider carefully what you need from your garden space and how much area is required for that activity and then you can be specific about the type of finish required and how much of it you really need. Many people automatically associate active recreation for children with the need for a large lawn area. But kids can just as easily have tons of fun on hard-standing areas. A small area can be doubled functionally by an adjacent wall, as all kinds of ball games can be played against a rebounding wall. Sand pits, trampolines, magic paths, tree houses, swings and jungle gyms all serve the purpose of active recreation without having to fork out for watering the lawn. 

(Of course, if you're going to buy all that stuff, you may as well have just paid for a borehole, or a holiday to Disneyland…..then, of course, there's the medical bills, the cat poop, the maddening, repetitive thwack of a ball against a wall…… O.K ….. I never said this was perfect) Anyway the point is that a green lawn requires a lot of water in the summer months and if you are able to use another material then you could save water and therefore money by doing so. This, obviously, is good. 

Stone-chip aggregates.
Functionally, stone-chip aggregates fall between non-porous hard-standing and completely porous surfaces. They can be walked or driven on but also allow water to soak through naturally to roots and ground water. Many people automatically shy away from the idea of stone-chip because it sounds like it would be difficult to clean and torturous to walk on. But this material is one of the most practical and cost-effective options for a water-wise finish in low-traffic areas of the garden. It also comes in a range of sizes and colours to suit most design requirements.

Stone-chips are good for:
• Planting in and walking on. (Use 6mm diameter for bare feet)
• Use in combination with cobble or timber edges to keep it where it is supposed to be. 
• Use it in combination with flagstone type pavers to create interesting textural variations.
• Use for level driveways when used with a sub-base material. (Use 13 or 19mm)
• Security. Sneaking up is impossible.

Don't use:
• for high traffic areas or steeply sloping ground. 
• for active recreation or play. It gets churned up by foot movement. Like Soccer. 
• Adjacent to a pool as the stones end up in the pool and then the creepy-crawly.

• buy in bulk as it gets very expensive in small bags
• Put a geotextile fabric under it so that it doesn't mix with the soil underneath it.
• use the smaller sizes (6mm diameter is lovely to walk on barefoot. 13mm is o.k. with shoes) 
• Put it down about 40mm thick. 
• use a soft broom or plastic rake to sweep / rake up leaves.
• lift and wash it every two years or so when it gets clogged with leaves and other debris. (This sounds like a mission but if you add up all the time you     saved mowing the lawn you are getting a bargain. I suggest you pay someone to do it.)

Fake lawn
Shock and horror! There was a time when I scoffed at the idea of fake lawn, but since then three things have changed.

Firstly water has become more expensive (and will continue to increase in cost); secondly the fake lawns have improved in durability and appearance and actually look pretty good these days. Thirdly, I have come across spaces where the lawn has been used and it works brilliantly (Admittedly mostly roof gardens), especially within the context of an ultra-modern garden space and combined with other non-traditional materials. (Like glass, rubber, aluminum and others) At present the cost comparisons are still being made but as the price of water increases I believe we are going to see a lot more of it in the future.  

I'm not sure how compatible it is with dog poop.

Porous surfaces
Try increase the area of porous surfaces in the garden or property. Hard impermeable surfaces inevitably channel water to a gutter somewhere, which leads to a gully which leads to a storm water drain which takes the water to a bigger storm water drain which dumps it in the sea, which evaporates to the clouds which rains into the dam and which you buy back later, to water your plants. Get it?

Porous surfaces mean that the water will percolate downward carrying nutrients into the earth below on your property, benefiting your trees as it augments the water table below. This is good because the roots follow the water down and later when summer arrives the trees have deep roots with which to siphon up the dropping water table. Incidentally this principle applies to all watering, as plant roots will generally go where the water goes, so it is better to water less frequently at larger quantities than visa-versa. The former means deeper roots will develop as they follow the water down and the latter means that all the roots will stay near the surface, and consequently freak out when you stop spoiling them with tons of surface water.  

Examples of porous surfaces are stone chip surfaces, mulch, grass blocks, lawns, and planting beds. Even fast moving water that has already been collected in roof gutters and pipes can be spread out at the bottom of the garden where it can soak away in a bog planting area, pond or simply into the soil.

Irrigation systems
The concept of an irrigation system may seem inherently indulgent, but it is not. 
An automated irrigation system allows perfect control of the amount of water being used in the garden. Each area (also called Zones or stations) can be fine-tuned to achieve maximum benefit for minimal water and combined with intelligent plant selection and grouping can save large amounts of water (and money).   Automated irrigation systems also allow for quick and easy manual adjustment of the quantity of water across the seasons. This adjustment can sometimes be automated by the addition of a rain sensor to the system which recognizes the presence of rain and adjusts the system to compensate on a daily basis. Automated sprinkler systems can get complicated when tanks, booster pumps and remote access is involved, but even the most inexpensive, timed shut-off valve fitted to the sprinkler hose pipe at the tap can save you the frustration of forgetting about the sprinkler/s and turning your garden into a temporary (and very expensive wetland) for a couple of hours. There are many different types of irrigation methods and it is best to call a professional to assess your needs.

Shut all the taps in the house and go check the meter, if it's turning you're losing water and money through a leak. Finding the leak on the other hand is not so easy. Call a plumber.

The lawn 
There is a good reason that the ubiquitous lawn is often maligned as the most gluttonous of beasts in the traditional garden. This is because it's true. 

However it's usually exacerbated by the fact that the lawns are too large, therefore naturally requiring more water.  Here again I blame the predominance of the European style garden for the inculcated idea that a garden must have a large expanse of lawn, because frankly, it doesn’t. So the question is…. how big does the lawn need to be? And, the admittedly cryptic answer is, big enough. 

By this I mean that when planning the layout of your garden it is best to be realistic about the size of the lawn and what it is going to be used for. If the lawn is only for the dogs to use the toilet then it doesn't have to be huge. Likewise if the intention is to raise the Proteas next pace bowler then your lawn area needs to be very, very long and narrow. (For spinners, don't bother with lawn. Put the dirt patch behind the toolshed where they can have a quick puff and tin of lager between over's. And the less run-up the better!)

The good news about lawns is that they are the often the garden designer's best opportunity to set up the architecture of the garden. Whether if be formal, informal or somewhere in between, the shape of the lawn is generally definitive of the way the spaces and forms fit together. And therefore strongly influence on how we respond to the garden. 

I do not want to go into a discussion here about the garden design in general as this article is about principally about water. However by realistically considering the functions of the lawn area in your garden you may find that a smaller area of lawn, perhaps strongly framed and thoughtfully incorporated into the overall concept of the garden, may in fact not only fulfill its functions perfectly but could also improve the aesthetics and, to borrow from the photo-sharing site Flickr, the interestingness of the space, as well as save you water, money and frustration over the years.

There are different types of grass that you can use and buffalo is generally considered the least thirsty. Kikuyu needs a lot more. Proper lawn care is a subject all on its own, but much of the success lies beneath the lawn in the preparation of the soil. Lawns generally require well drained soils, regular feeding and judicious mowing to look their best. 

Soil Management
Soil is the growing medium of the plants in the garden and besides providing the cache of nutritional elements required, it holds the water in which to dilute or suspend these elements. Plants can only 'drink' and therefore no matter how nutritious the soil, without water it is useless. Soil management therefore includes both addition of nutrients and the facilitation of water retention properties of the soil.

Sandy soils are highly porous and retain very little water whereas clay soils tend to cause run-off once saturated. Sandy soils need to be improved by the addition of compost and humus so as to improve the water retention attributes of the soil.
In very sandy soils like we have in parts of Cape Town it is prudent to add almost 50% of the volume of compost into the soil. This compost then absorbs the water and releases it (with nutrients) into the soil for the plants to absorb.

With clay soils the soil is fertile but the lack of air makes it difficult for water to percolate through and plants to grow in and they tend to grow slowly. The idea is to try break up as much of the surface as possible and incorporate compost, mulch and other organic so as to improve the soils structure. You can also add lime and other additives which will improve the friability and texture of the soil as deep you and your back are willing to dig it in. After that choose you plants wisely and they will triumph in time.

Soil management in general is often the essential difference (second only to succession planning) between great gardens and average ones and whilst soil science is a complex and in-depth field most of us get along fine with the regular application of ready-to-use products that will give great results for a modest outlay. 

Mulch is a layer of rough organic material that lies on top of the beds in order to reduce the evaporation of water from the soil and cut out light to weed seeds, thereby reducing their rate of germination. Regular mulching is a very effective way of saving water. You can also use stone chips if the wind keeps blowing away the lighter material. 

Compost is a finer organic material that has undergone a process of chemical and physical decomposition that releases nutrients into the soil. Good compost is great for the garden; bad compost is a waste of time.
And now... the truth about the ubiquitous domestic compost heap…..

As a kid the compost heap was a source of great fun. It was great for bug hunting, hiding behind (or in), running around and foraging in to find things to throw at people. However, rarely was it any good for soil management. And, from what I can discern, no benefit was gained by my weekly chore of spreading that detritus all over the garden. Now I am not being negative but, even at the time, I honestly believed that that pile of grass clippings, sticks, leaves and kak in the corner, between three zinc sheets and four wonky poles, did nothing for my mum's garden….. or frankly, my Saturday afternoons.

In fact it was only years later when I learned about nitrogen fixing, thermophilic fungi, compost accelerators and much more that I realized I had been simply chucking unprocessed dead stuff on the garden for all the years. A bit like eating the apple tree instead of the apple and hoping that the doctor will stay at bay, to mangle a perfectly good a metaphor. 

The truth is that producing compost is a scientific and technical process and unless it is done properly, an enormous waste of time and space. At best an un-loved compost heap is a dumping ground, a haven for rats and mice, snakes, bugs and who knows what else. And end result is so often useless. However if you are serious about the production of compost for recycling purposes it can be done on a small scale at home if one is judicious, patient and methodical about the process. Buy an appropriate sized compost bin and go for it. It feels good to recycle organic matter and, if due process is followed, it is perfectly good compost. You can also make compost teas, grow worms and do all sorts of exciting stuff with it once you’ve produced it. 

Otherwise you can just go buy some at the garden center. (And pay someone to chuck it around). (I promise I do not own any shares in compost companies)

Soil additives
Soil additives are generally derivative products containing specific or various elements and nutrients that are, for all intents and purposes, instantly available for the plants to absorb. Like Science Diet for plants. They generally have no real water retaining properties. And are essentially fertilizers, organic or inorganic, fast release or slow release. Be careful not to overdo them and always follow the instructions, as to much of a good thing goes bad (or rather toxic) when it comes to fertilizer. Many plants will tolerate only slow release formulas. If you’re an organic aficionado you'll want to make sure it's all got all right accreditations before using it. 

Trace elements 
Trace elements are micro-nutrients that many soils lack and when attempting to grow plants in places where they would not naturally occur (which is all the time) then often a regular dose of micronutrients will make the difference. They are not used for indigenous plants. You can buy them at the garden centers. 

Gels in soil
There are certain water retaining gels that are sometimes used in pots and hanging baskets to increase their moisture holding capacity. They do work but are not really a feasible option for the garden as you would need tons of the stuff and they come in little boxes. Also be careful to mix it well into the soil otherwise they can become a sticky glutinous mess of epic proportions real quick.

Pipes to roots
These are pipes that lead down to the root ball of a plant so that water and nutrients can be delivered directly to the roots, thereby cheating the process of evaporation that occurs when the water is deposited on top in the traditional manner. 

Non-potable water
For many gardeners out there out there the immediate response to the escalating cost of water is to try and get water from some other source and only use the treated municipal supply as washing and drinking water. These other sources are generally called non-potable water but do not come free. Below is a general overview of non-potable sources and a brief explanation of what they are and what they entail cost-wise.

Traditionally used in the agricultural industry only, boreholes have become more prevalent in larger gardens. Boreholes can be expensive, because they require large, costly machinery to drill deep into the ground through rock and other material in order to access the water. They are a significant investment in a property that warrants it. They are not really a realistic option for most properties, although this may change as the cost of water increases. Besides the cost of drilling, there is also the cost of the pump\s, tanks, water and electrical reticulation.

Well points
Well point's are like mini-boreholes and are definitely a realistic option even for small gardens .They're drilled with simple tools using water pressure and therefore only feasible in sandy soils where the water table is high. Some well-point contractors will divine for water on a no find / no charge basis. Others will charge a small fee. Unfortunately not all sites have the high water table required but it is worth trying (especially on the Cape Flats) 

Natural springs and streams
These are rarely an option and can have legal implications with regard to water rights and potential disputes with other users downstream.

Rain-water tanks.
Nowadays tanks come in various different shapes and sizes so they can be positioned where they are less visually intrusive. With some imagination and creativity tanks can be aesthetically integrated into the garden. The benefit of the tank for the garden in the winter rainfall area is more or less limited to one tank of water at the end of the winter, because when it stops raining the tank stops filling. Although using the tank water for the cistern should reduce your municipal water bill for sanitation during the winter. If you can afford the space then tanks are a cost effective and direct water saving option. You will need to elevate it or add a small pump on order to the water get it to where you want use it.  

Grey water 
Grey water is municipal water that has been used for washing and then reused in either the garden or the cistern to flush the toilet. The water is stored temporarily in a tank and then pumped out to where it will be used for a second time. The water should be re-used as soon as possible because the soap and bacteria in the water can start to smell if it is stagnant for too long. Some gardeners have also voiced concerns about the use of excessive salts present in soapy water building up in the soil over the years. (Use soaps that are approved for grey-water systems)  Others have suggested using a separate tank specifically to capture the clean water from a preparation bowl (the one you use mostly for rinsing vegetables and fruit whilst preparing food) in the kitchen. Alternatively a toggle switch on the line can fitted to provide the option of flushing especially dirty water away rather than to the tank.

Plant in winter
This is a simple trick in the Western Cape where all the rain comes at the same time and is then followed by a long, windy drought. If you are planning a major re-plant and do not have an automated irrigation system then you can save a lot of water by planting in the early winter.From April onwards usually does the trick. The plants then have the cool winter weather to settle in and set out some roots before the onset of the howling South Easter come December.

Remember that all the hard landscaping can be done anytime of year and this seasonal planting approach is only really going to help if you are doing a major re-plant. (Admittedly landscapers won't like this option because it complicates the installation process significantly)

Water dams around plants
I often put shallow dams around trees and larger shrubs so that they get a little bit extra. I don't bother with smaller plants.
Water-wise design
Good design will go a long way towards saving water, electricity and other resources. If you look at your property holistically and utilize a range of water and energy saving methods you can accumulate efficiencies across a number of methods, whilst still creating an aesthetically pleasing environment in which to live in. A well considered landscape or architectural plan is the logical starting point. 

Pee on (or next to) a plant 
Seeing as we're throwing everything but the kitchen sink at this problem I may as well hang this out there as well. 

Gentlemen, taking a leak in the garden is a good thing, especially after drinking beer. I mean you pay for the beer, you pay for the petrol to get the beer to your house and you pay to keep the beer cold… so do you really want to be paying to flush the leftovers down the pipe? Remember, it takes about seven liters of water to flush away 375ml of used beer, so…for example, if you're having a party with a few mates and everybody's drinking pretty hard, and you find that if one mate goes to the toilet every,… say… 25 minutes and you’ve got ten mates and every time a mate goes, then it's seven liters of water, then that’s …ah…um … you do the math, but if your mates are anything like mine you’ve basically flushed a way a swimming pools worth of water for nothing. 

So pee in the garden, it's good for you and your plants. Really it is, check it out on the internet. Note this only applies to men. Ladies, you're on your own here, make your own call. Also use your discretion when drinking in public, top floor apartments, kiddies' parties, etc. Please, no common sense failures. 

And remember fellas, that big tree has grown up already; so pee on the little guy…..

Posted: 1/16/2012 (3:16:09 AM)

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