When did summer arrive for you this year? It is a question I’ve been asking friends and acquaintances in recent weeks in an attempt to conduct a purely anecdotal survey comparing gardeners’ experience this year with last, and to see what horticultural differences there might be in various locations.
Unscientific though this may be, the answers are interesting, particularly when you compare the experience of people living in coastal areas with those gardening further inland, where the climate is generally drier.
I live near Abu Dhabi’s Corniche, and although I noticed the temperature started to soar three weeks ago, the realisation only hit home on May 8, when the inevitable finally happened and the humidity spiked. A year ago, I lived further inland and I can see from my gardening notes that, perceptually at least, summer came later and that it was heat, not humidity, that heralded the change. On May 23 last year, I had to wear shoes on my morning tour of the garden to stop the hot tiles from burning my feet.
Now that the summer onslaught is upon us, it’s time to do those last-minute tasks that will allow you to effectively put the garden to bed and to reschedule essential garden visits to the margins of dusk and dawn as daytime gardening becomes increasingly uncomfortable.
Certain plants may already have started to register the increased temperatures and strength of solar radiation. The stylish umbrella plant (Cyperus alternifolia) is usually a good indicator of increased temperatures and the need for more regular irrigation, not least because it is such a thirsty beast. Like a tired teacher looking forward to the end of term, this Madagascan relative of Egyptian papyrus may already be looking a little ragged around the edges, something that is accentuated by the brownish spadix that forms in the centre of the leaf cluster when the plant is in flower. Given that this plant normally grows in tropical swamps and thrives best when its roots are wet, I am always amazed to see it feature so heavily in UAE planting schemes. If you have Cyperus growing in a container, you should consider moving it into a more shady position.
Two other plants that display signs of stress associated with the sun and heat are the Sago palm (Cycas revoluta) and cardboard plant (Zamia furfuracea), both of which bleach alarmingly when exposed to intense, direct sunlight for long periods. Interestingly, although these plants belong to different botanic families (Cycadaceae and Zamiaceae, respectively), both are cycads, a type of plant that dominated the plant world in prehistory. Some of the earliest cycad fossils are almost 280 million years old.
When used as an understorey planting below trees and taller shrubs, cycads will require little extra care. However, if you have them growing as specimen plants in full sun you can always take them indoors, where they will make excellent houseplants for the summer.
Generally, cycads are hardy in nature but susceptible to over-watering and will die quickly if their stems and roots begin to rot, something that can be a problem during a UAE summer, when irrigation systems are running daily. Therefore, it is important to make sure that plants with similar irrigation requirements are located next to one another. When it comes to irrigation, Cyperus, Zamia and Cycas do not make good immediate bedfellows – although I have seen them planted closely together on several occasions because they are so visually striking, often with disastrous results.
If tender plants can’t be moved, consider covering them with a shade cloth to protect them from the summer sun. Meshes and nets are readily available from garden centres and hardware stores. I cannot help but think, however, that having to do this in the garden represents some failure in the original planting scheme. Even with the UAE’s limited palette of commercially available plants, there are a sufficient number of species available for sun lovers to be used in garden hot spots and more tender specimens in shade. However, when temperatures soar like they did last year, even desert plants can need extra care, and even cacti can get sunburned.
One of the most widely used and available cacti here is Echinocactus grusonii, more commonly known as the Mexican barrel cactus. Highly attractive, particularly when planted en masse as an architectural ground cover, the species is widely perceived, like all cacti, to be virtually indestructible. This is, unfortunately, not the case. On a visit to Al Ain Wildlife Park and Resort last summer, I saw Echinocactus that had puckered and blistered in the sun and others that had effectively been cooked, like roast potatoes, inside their skins.
Part of the reason for this was extreme temperatures. On some days thermometers registered 57°C. However, as the resort’s landscape manager, Jamie Hilyard, explained, high temperatures alone weren’t the whole story. Like most of the cacti species that are imported here, Echinocactus comes from an environment where daytime temperatures are high, but nocturnal temperatures are often very low in comparison. This allows the plants to release the heat that builds up inside them during the day and to cool down at night.
This temperature differential also produces invaluable moisture that forms dew each morning, thus providing plants with essential irrigation that enables them to survive throughout the day. In the UAE, however, day and night-time temperatures in summer are often quite similar, so there is less opportunity for the plants to chill out as they do in the Sonoran and Mexican deserts.
While cooked barrel cactus is unusual and extreme, it does point to the importance of good plant research and suitable species selection. More than anything, making the right decisions at the early design and planning stage of your garden and putting the right plant in the right place will always be the best and easiest ways to combat the effects of the UAE’s unforgiving summer sun.
A version of this article originally appeared in The National, Abu Dhabi
Writing to Inform 