Six pages of gorgeous images and step-by-step guidelines to create a living roof. The Indigenous Gardener Magazine has done a wonderful job. Be inspired! Enjoy!
Imagine our cities with birds and butterflies flitting from building to building. Imagine views from tall buildings that include roof tops full of plants, rich with life and colour and the sound of birdsong and insects. This is starting to happening all over the planet. People are seeking alternatives to the alienating and sterile world of concrete, without moving to the countryside. Roof gardens provide all of this and much, much more!
I have dreamed of creating my own green roof for so long it hardly seems real that it is now in. This post is about the benefits of green roofs and quite a detailed ‘How To’ guide for those who wish to do the same. Early inspiration came from the Green Roof Pilot Project (GRPP) at eThekwini which is testing various options that provide healthier urban environments. This project among others has shown that these living roofs (as they are also called) naturally increase biodiversity and are aesthetically beautiful, but there are numerous other good reasons to seriously consider installing one:
- They insulate the house, reducing the amount of cooling and heating required
- They lower the amount of storm water run-off
- Improve air quality through the reduction of air borne pollutants, including harmful carbon monoxide.
- They absorb chemicals and heavy metals from rainwater
- There are positive climate change impacts via absorption of carbon dioxide and the release of oxygen during photosynthesis.
- They help insulate for sound
- They reduce maintenance cost of roofs and increase its lifespan by two to three times.
- Can assist in the alleviation of food security issues.
- Provide fire resistance
- Offer electromagnetic insulation.
There are broadly two options for installation. One way to go is planting in trays. I have used the direct method which involves placing the shallow amount of growing medium on top of various protective and drainage layers which I will show step by step.
Before you start though it is imperative to ensure a structural engineer has confirmed that your roof can take the extra load (or if you are building from scratch engineer into the design).
We began by installing a serious waterproofing product called ExtruBit ® . This stuff looks a bit like wet suit material is flexible and really tough. A company called Bertrade did the installation which involved heat sealing the overlap areas. No mean feat in Durban’s hot and humid February.
The next three layers provide the drainage and help ensure the soil won’t get into the full bores. Pula Water supplied their amazing drainage mats (Flow-Cell ®) which are sandwiched by geotextile. This was a cinch to install, somewhat reminiscent of playing with Lego as you are rewarded with a very satisfying click as each mat slots into the other! In addition to ensuring the water will drain
away they are designed to do so slowly so plants have time to drink.
You are now ready for your soil mix. My soil has come out of the ground being dug for the water harvesting tank. Not very nutritious so I have mixed it half/half with pine bark compost from Grovida.
In addition I have added bags of organic accelerator, agricultural lime and 2:3:2. Over and above general dispersal of the above, each largish plant hole received a handful of the extras to give a nutritional boost.Before we talk the about the most exciting bit which is obviously the plants I have to share with you the less interesting but vitally important info on how to deal with your full bores. This is the area you roof garden will ‘fall’ to (i.e. slope down to) and it is crucial that you have sufficient drainage or your garden will fill up and swim over the edge of it. To help slow down the process in the event of heavy rain this is what you can do:
Choose your plant species carefully. It goes without saying your locally indigenous/native plants must be selected and these should be water wise and heat tolerant. Plants that grow in cracks and crevices are ideal. Bear in mind that the soil is shallow and will dry out quickly. Plants should (in the main) also be low growing and wind resistant. Ideally they should also be self seeding to replace themselves when stressed by heat and water fluctuations.
They beauty of using the correct plants means that after they have been established irrigation is seldom required. Plan to utilize at least one of the many water harvesting options. Gutters and grey water re-cycling are easily installed. (Detailed posts to follow).
For those of you in Durban South Africa here is a list of plants that will do well:
|Aellanthus parvifolius, Aptenia cordifolia, Aloe maculata, Aloe cooperii, Bulbine abyssinica, Bulbine natalensis, Cissus quadrangularis, Cissus fragilis, Crassula multicava,
||Crassula hirta, Crassula ovata, Crassula obovata, Crassula perofliat, Crassula vaginata, Aloe rborescens, Aloe rupestris, Aloe thraskii, Aloe van belanii, Cotyledon orbiculata,Delosperma rogers|| Hibisucs calphyllus, Kalanchoe thyrsiflora, Nymphoides thunbergiana, Portulacarai afra, Stafpelia ginantea, Vernonia capensis
I know this garden will give us much joy in the years to come. I hope you’ve been inspired!
P.S. I know many of you are desperate for the post on the Vertical Garden. The scaffolding is still in front of it and the minute it’s down I’ll be able to show you it in all its early splendor. Here is a little glimpse of what is flowering at the moment.
Useful Reference: Etekwini Guidelines Document
I have developed quite an emotional attachment to my worms. For good reason, they are truly amazing and greatly underappreciated creatures.
If you haven’t yet discovered the joy of worm farming I urge you to give it a go. For the yet to be initiated:
Vermicompost is the product or process of composting using various worms, usually red wigglers, white worms, and other earthworms to create a heterogeneous mixture of decomposing vegetable or food waste, bedding materials, and vermicast. Wikipedia
Earthworms aerate, till and fertilize the soil, breaking down organic waste into plant-available forms, improving the soil structure and nutrient and water-holding qualities of soil. Current farming practices that use chemical fertilizers, pesticides and over-tillage of the soil kills earthworms and other beneficial organisms, leading to poor soil fertility, loss of soil structure and soil erosion. At the same time, rotting organic waste dumped in landfills is polluting our underground water supply and releasing vast amounts of greenhouse gases which contribute to global warming.
Earthworms eat organic waste and give us healthy soil and organic fertilizer in return. The knock on effect is healthy plant growth and food that is significantly more nutritious and delicious. Farming/gardening without man-made chemicals enables us to avoid poisoning our soil, environment and bodies. This perfect partnership is easy and fun to develop on a smaller scale at home.
There are numerous commercial systems available but you really don’t need a hi-tech operation to get started so go with what your budget allows or make your own. My
son has designed this ingenious system which enables us to maintain the health of the farm and easily harvest the ‘gardener’s gold’. These simple re-cycled plastic boxes are divided by a section that has holes cut into it. One side of the box is filled with food until full. At this point we begin filling the other side leaving the first side to break down further. As the food disappears the worms will move into the food rich section leaving behind the easy to harvest worm castings which contain up to 100-million microbes per gram – up to 20 times more than ordinary soil! Added to your garden, these microbes continue to break down organic matter into plant-available forms, thereby enabling plant roots to take up nutrients that would otherwise have stayed bound in the soil. These beneficial organisms also suppress the growth of pathogens, which means healthy soil and healthy plants. In addition to harvesting the castings we catch the worm wee (leachate) which drips through a hole in the base. It makes a wonderfully nutritious tea when mixed with water. Tea for plants that is :-).
My farms, however, we getting a bit to much attention from other wildlife in the garden. I realised that the aeration patches had been gnawed through and at least one rat was feasting on my red wrigglers. I’m all for ‘the cycle of life’ etc. but realised my population was taking to much of a knock. It was time for some maintenance and harvesting anyway so I got stuck in. The old aeration patches
were replaced with wired mesh, the harvestable sides were harvested, the worm filled sides set aside and the whole box was given a good clean. Worms were returned with a note on top to advise other family members to now only feed on the one side (yes it is necessary in my family!). Worms are now safe from predators and I have buckets of gold to mix into my veggies boxes.
P.S. I know many of you are very anxious to see images of the incredible vertical garden. I ask you to bear with me a little longer. The scaffolding will be coming down soon and then you will get a much better sense of this exciting project. If you can’t wait to get started on your own VG but need some help, get hold of the plant wizard James Halle on firstname.lastname@example.org.
The build seems to have accelerated, or maybe its just because we are starting to get to the best bits. The most exciting installation, so far, is the vertical garden. I’m going to be really mean though, and not show you a single picture yet because it is so magnificent, and the landscape artist James Halle is so talented, it has to have its very own post with lots of elaboration. Watch this space!
The shuttering has come off the ‘floating’ staircase, and although this is not a green aspect of the build it is so beautiful I just need to show it off!
The interior painting has commenced. There are loads of eco-friendly paints on the market these days. They are much lower in volatile organic compounds (VOC’s) which basically means toxic stuff our bodies don’t like. Confirm this with your paint supplier though because you won’t automatically get a low
VOC paint as there are still mixed perceptions about its efficacy. Rest assured, they are equally effective and no more expensive than traditional.
The veggie garden now has 3/5 veggie boxes installed. We are using a plastic timber product. These recycled planks are now widely available. They are 100% recycled plastic so get great green points. We lined the base with chicken mesh too keep out the moles. Galvanized rods secure the sides from bowing out. This stuff will last forever, looks attractive, is easy to install and cheaper than recycled brick options which we had considered
I was really excited to see my Trichocladus crinitus (Black Witch-hazel) in flower. This small indigenous tree is quite rare and the petal form delicate and unusual.
There are lots of eco-friendly options for insulation these days. We’ve gone with a product made from recycled plastic bottles. The recycled newspaper product was a close contender. The team on site report that the green stuff is really great to work with as it doesn’t shed prickly bits like the more traditional pink products.
The off-shutter concrete wall has had its first of two buffs and polishes. It looks fabulous. I love the industrial /contemporary aesthetic and the honesty of the material. Its a great ‘hard’ contrast to the green abundance of the garden. Very happy with how its turned out.
The Erythrina humeana (Dwarf Coral Tree) are exquisite at the moment. A really showy splash of red at the bottom of the garden.
The pool has a new rectangular shape and fits snugly into the space of the old. The reed beds are almost complete. It’s going to be great fun planting them up. I’ll be sharing much more information on how to install an eco pool. Suffice to say at this stage that the plants will do all the filtering of the water and no harsh chemicals will be required. The plants and water provide the foundation for the wetland eco-system and we look forward to the
bird, amphibian and insect life we will be attracting.
Next to the veggie garden we have two of the Baunia’s in flower at the same time. Gorgeous!
The whirly gigs are on site. Prith and Eamonn are finding them quite amusing. Definitely a first for them as they are usually found in industrial builds. We are putting them in to draw and pull up the cool air that will pass over the pond outside and into the hallway. The best way to reduce the need for air conditioning in this space.
So overall fantastic progress! And still so many of the best bits to come:
- Vertical Garden (as promised)
- Roof Garden
- Rainwater harvesting
- Eco Pool
- Veggie garden
- Worm farming
- Grey water recycling
- Solar system
- Induction geysers
- plus…plus… plus
Many think the subject of compost is about as exciting as watching grass grow. I’ve long been teased about my obsession with the stuff but noting the 1,397 books available on Amazon I know there is a community out there that are as passionate about it as I am. For example, this is what Bette Midler has to say:
My whole life has been spent waiting for an epiphany, a manifestation of God’s presence, the kind of transcendent,magical experience that let’s you see your place in the big picture. And that is what I had with my first compost heap.
I’ve struggled with compost ‘heaps’ in awkward spaces, then upgraded to bays in rickety fencing (now collapsing) so I’ve been determined to put in a more user-friendly system at the Gorgeous Green House. On the design wish list:
- at least 3 bays for good rotation
- sturdy construction
- opening/gate front for easy turning over and removal
We have a lot of old paving to re-cycle on site so I asked my builder for a quote to build them with the bricks. Phew, quite a lot more than expected. Plan B was to ask a fencing company for a quote. Also quite a lot more than anticipated. This led us tho thinking ‘how hard could it be to dig in a few poles and fence them in’. We checked out the material costs (a fraction of the fencing company quote) and were further delighted to see the company makes gates that are super easy to install. The result is spectacular. I am thrilled as they will be really easy to use. I’ve had piles of leaves and weeds building up all over the garden so its been wonderful to get them into the correct place awaiting their final home in the veggie garden. Here is our process:
Conventional composting wisdom dictates that the best compost is a mixture of brown (leaves, twigs etc) and green (lawn weeds etc).
Leaves will also break down into wonderful compost though a bit more slowly. I shared my leaf ‘cage’ idea in the post of 10 June but check out this guy and his ‘cage’ with grass only:
As the Southern Hemisphere is moving into Winter, Autumn first provides her most important harvest: fallen leaves. Natures perfect cycle of replenishment to the soil and the provision of nourishment for all life in the ecosystem. And what do we do with this abundant gift? We sweep it up into plastic bags and send it off to land fill. Come spring we drive to the garden center and buy compost in more plastic bags.
Where did we get this idea that leaves are unsightly and need to be done away with? When you think about it for a minute it really makes no sense. I appreciate that leaves on hard surfaces are not a good idea so lets sweep them into the flower beds where the mulching provides moisture and nutrition through the harsher winter months.
Once you get excited about the difference it makes to your garden (check out my winter colour!) you get quite greedy for the stuff. I frequently stop on verges as I see people raking leaves into bags and ask them if I can have them. I get a few strange looks (and comments) but most people are too flummoxed to say no! hopefully I leave them with some food for thought.
I am currently just making a big pile with the leaves but if you prefer a slightly neat tidier approach I’ve also made this very simple cage out of wire fencing.
In a few months beautiful quality compost for free!