After a long COVID break, I returned to the column receiving a request from one of our readers, Tusher from Narayanganj, who wrote — "I have a big roof that I want to decorate with a garden. I'd like your suggestions in this regard. I basically want to know about plants that would grow on the walls of the roof's railing, plants that would be a great choice for growing in pots, and tree beds. It would also be great if you could mention the names of the plants that I can find from a nursery."
So, first, hello Tusher and thanks for your interest in rooftop gardening. How lovely that you have a big space to make your dream come true! First, let me tell you that I am not a professional in this field. As I have a personal interest like you, and have love for plants and green life, it is my mission to share my personal learning with others and learn from others too. Following your request, I shall try to share my experiences on overall roof gardening issues that might help you to some extent.
Let me start with the view of my next-door neighbour's garden — in a not-so-large space, but I found it relevant to this topic.
There are some critical issues of roof gardening — availability of sun light, and a proper drainage system as well as the load bearing capacity of the building; and then designing the space in a practical manner. At this stage, it would be good to get professional help for landscaping — designing the entire space and engagement of a professional 'mali' or gardener to do the real leg work. This consultation will help you in the long run, to have a well-planned garden to feel proud of. You may also go at it alone if you have the time. As an owner of the roof, the choice is plenty. You may grow all season flowers for a decorative garden or fruit bearing plants for a round-the-year fruit supply. You may also create a greenhouse for orchids you like, a small pond for water lilies, a grass bed under an umbrella — ideal to have tea in the evening.
Before you make up your mind, you need to start with the very first question — how much daylight your roof gets — all day, partial, or for a few hours? Your plant choice will mostly be depending on those, say for fruit or flower-bearing big plants, sunlight and natural showers are necessary along with a good drainage system to get rid of the extra water from the roof.
For selection of the plant beds, I would suggest you to go permanent type for all types of plants according to the size, lifespan of the respective plants. Usually, the bigger plants get the wall and others are organised following the same rule.
You may engage the mason to construct the plant holders — long with deeper depth to grow big plants — medium height beds for the medium range plants and so on. This way, you will be able to create layers of plants which will make the view nice too. Here, I would suggest you to go for the permanent type — cement-made holders with legs so that it saves your roof from damage. There should be some gaps at the bottom of each container to allow regular cleaning of accumulated clogs and most importantly, prevent your garden from becoming a home for rats!
As I said earlier, the general rule for a roof garden is to have big plants with longer life near the walls, such as for mango, orange/malta, guava, lychees, pomegranate or drum stick/shojne etc. I am in favour of creating a row of plants, but all depends on the length of the space and availability of sunlight in the area.
The next level is to create for semi-permanent type plants like papaya, lemon or dragon fruits and such.
On the other side of the roof, especially the front side of your roof walls/railing, you may consider all-season low maintenance flowering plants like bougainvillea in a range of colours to create a year-long view.
You may also grow drop down creepers to give a greener look to your building. Beside the regular type, you can create a green roof with the help of a civil engineer by curating that part of the roof.
A roof garden allows us to try so many things — with big plants, evergreen grasses, shrubs and flowering plants. I personally prefer the deshi look than the curated garden. Rooftop gardening comes with so many options which have to be decided based on the availability of time, money and interest of the gardener/owner. As you have a large space, you have more options.
You can create a colour scheme of your garden after visiting a few nurseries and upon discussions with the associated people. You also need to ensure a steady water supply, for example by installing a portable pipe. In addition, engagement of a person who has interest, basic knowledge and love for plants will be essential. Your regular visits will ensure overall wellness of your garden.
Please note that rooftop gardening has its own uniqueness, as well as everyday challenges. There will be surprises and disappointments or heart breaks too. You need to be a plant lover for life to truly enjoy it!
Photo : Laila Karim
Please feel free to send me an email to share your thoughts, feedback, and photos of your garden, or to tell your story; or ask a question on gardening. Email: firstname.lastname@example.org