A parade of exotic blooms

by Elizabeth Shaheen
Why not put into action a novel idea and create your own green - or whatever colour you crave for - living-roof?

A great deal of current appeal in green roofs has rested on their treatment at large, frequently public buildings in Europe.

But you can create one on your porch-living-roof, garage-living-roof, tool-shed-living-roof and summerhouse-living-roof, even a-living-roof on your balcony. Even your house roof could be the envy of all who set eyes on it.

By colouring up, your roofs will result in attractive focal points adding innovative character to your garden setting.

In Scandinavia, turf roofs have a long-standing history dating back hundreds of years. Such roofs not only look good but they also provide insulation in winter and lend a most welcome, cooling hand in summer, and are efficient sound mufflers.

There’s more. A living-roof provides a haven for wildlife and it will hinder the run-off of rainwater.

Put in your mind’s eye a rich purple roof made from Portulaca grandiflora Hybrida. Or a crisp, snow-white roof made from a white form. A pink-fizz-roof would be provided from its pink variety. Very little soil is required and that won’t jeopardise the structure and the roof’s waterproofing.

When selecting your plant material, make sure that it is not too heavy for the structure after heavy rains. If you desire a variety of heavier plants, then you will need to allow for a depth of growing medium of approximately 100-110kg per square metre.

Go for composts or coco-peat, which are by far lighter than soils. Then you will avoid excessive weight.

You will need a depth suitable for your selection of plants. If you think about it, plants grow quite contentedly in 15cm pots.

You don’t need a flat roof for your roof garden. In fact, a sloping roof would show its colour more than a flat roof would.

Experiment with plant species. What you aim for is a personal choice. But I would be inclined to go for a wide variety of species replicating a naturalistic look of a garden setting, with a wild look about it.

Long, wispy grasses will add a veil of a genteel affair. And brilliant-coloured climbers would look simply gorgeous when just left to fountain down over the edge of the garden structure.

Ideally, the plants should be tough and hardy. Wild English meadow flowers would look absolutely darling. As too would low-growing perennials and hardy sub-shrubs.

Small deciduous trees would look good, such as Cassia fistula with its elongated bouquets of dangling flowers in torch-light yellow.

To my mind, colour, colour and ever more glorious colour would be what I would aim for.

Succulents would be ideal for coping with the summer heat. Choose tropical and subtropical plants and include some bulbs.

You could even grow fruiting vines such as grape or passiflora. Imagine plucking the fruit from the gangling vine - simply indulgence itself. Envisage a citrus tree providing an ever more focal point!

The ideal method of watering your creation would be to lay drip pipes in rows 15cm apart and set it with a pump and timer so that you don’t have to worry about it.

Your roof garden will need feeding in the same way as your floor garden.

You will need a suitably-sized pond liner, preferably one piece. Butyl rubber is the best and you can obtain it from Al Mahroos in Bahrain; ample preservative-treated wooden planks to make the frame and four to six sturdy wooden posts to support it; in addition to the growing medium to sustain the plants.

Lay the polythene or butyl rubber over the existing roof. Position the sturdy wooden posts in concrete along the longest sides and corners of your structure, and cut in such a way that the posts project above the roof to the depth of the frame you require.

Then, using your wooden planks turned on their lengths’ edges, form a crossword-puzzle-style-grid to divide and hold the growing medium required.

Each box should be around 30cm square and to a depth of between 5-20cm, which would rest on the type of plants you plan to grow.

Secure the frame to the posts. This makes certain its weight is carried by the posts and not by the structure.

Fill each section of the timber framework with a lightweight substrate such as leca, crushed brick, vermiculite (which you can purchase from Agricultural Services on Janabiya Highway) or coco-peat with a proportion of compost.

Mix in some organic soil-rich granules, which you can obtain from Bahrain’s nurseries. You will need to include some either chemical or organic potassium.

You can lay your drip pipes either on the butyl rubber or on top of your growing medium or halfway between the two.

Sow your selection of seeds or plant your chosen belles - whatever your heart desires. But avoid trees that are likely to grow too broadly or too high. You want to aim for low maintenance as possible.

So, I look forward to seeing Bahrain’s sky-high gardens strewn all over the island.
Elizabeth Shaheen - GDN - 24 June, ‘07