The New Climate Reality
Hong Kong is getting hotter. This is not a prediction; it is a measurement. The Hong Kong Observatory’s data is unambiguous: the number of Very Hot Days — those where the mercury crosses 33°C — has more than doubled since the 1980s. The city now averages forty-seven such days annually. By 2050, the Observatory’s mid-range projections suggest we will see between eighty and one hundred and twenty. At the same time, rainfall patterns have become more violent and less predictable. The wet season delivers more water in fewer events; the dry season stretches longer and bites harder. A garden designed for the Hong Kong of 1990 is a garden designed for a climate that no longer exists.
Most Hong Kong gardens are not designed at all, of course. They are inherited: a cluster of Ixora and Duranta passed from one landlord to the next, a Ficus hedge that nobody planted but everyone trims, a patch of St. Augustine grass that requires staggering quantities of water to remain the colour of a hospital corridor. These are gardens of habit, not gardens of thought. And habit, in a warming climate, is a slow form of plant murder.
The alternative is the dry garden. Not a desert garden — Hong Kong receives nearly 2,400 millimetres of rain annually, which is closer to a monsoon climate than an arid one. But a garden designed around the principle that water is unreliable: that it comes in floods and then disappears for weeks, that it rots roots in summer and vanishes in winter, and that the plants most likely to survive the next two decades are those that have already evolved to handle exactly this pattern of deluge and drought.
The dry garden is not a style. It is a strategy. It can look like a Mediterranean hillside, a South African fynbos, an Australian coastal heath, or a meticulously composed Japanese rock garden. What unites these approaches is a shared horticultural logic: free-draining soil, plants that tolerate wet roots in summer and bone-dry roots in winter, and a designer who has accepted that irrigation is a supplement, not a foundation.
The Mediterranean Model: Why It Works Here
The climates that most closely mirror Hong Kong’s trajectory are not tropical. They are Mediterranean: hot, dry summers punctuated by brief, intense wet seasons. The difference is that Mediterranean plants have had roughly five million years to adapt to this rhythm, while Hong Kong gardeners have had about five minutes.
The Mediterranean basin — southern Europe, North Africa, the Levant — is the obvious reference point. Plants from this region understand the assignment: grow vigorously during the cool, wet months; shut down during the hot, dry ones. Many have evolved specific adaptations that make them unusually well-suited to Hong Kong’s particular version of climate stress. Silver foliage, for instance, is not a decorative choice — it is a heat-reflecting strategy. The fine hairs on the leaves of Santolina chamaecyparissus (cotton lavender) and Convolvulus cneorum (silverbush) trap a layer of still air that reduces evaporation by up to forty percent. In a Hong Kong August, that is the difference between a plant that looks structural and a plant that looks cooked.
Lavandula dentata (French lavender) is the lavender for Hong Kong. Forget Lavandula angustifolia (English lavender) — it wants cool nights, alkaline soil, and a climate that does not exist south of the 30th parallel. French lavender, with its toothed leaves and slightly less demanding temperament, will survive a Hong Kong summer if given three things: full sun, soil that drains like a sieve, and a hard prune in late September, cutting back to just above the old wood. Do not be gentle. Lavender that is not pruned hard becomes woody, sprawling, and dead in the centre within two years. The plant will look brutalised for about six weeks after the cut. It will recover. Trust the process.
The silver-grey foliage of Mediterranean plants is not a decorative choice. It is a heat-reflecting strategy — one that took five million years to evolve and about five minutes for a Hong Kong gardener to appreciate.
Rosemary is more forgiving but subject to the same pruning rule. Salvia rosmarinus (formerly Rosmarinus officinalis — the botanists reclassified it in 2017 and the gardening world is still quietly furious) will grow into a decent shrub in Hong Kong if planted in a raised bed or on a slope. The prostrate forms, particularly ‘Prostratus’ and ‘Irene’, are excellent for cascading over low retaining walls where their roots can stay dry. Upright rosemary in a Hong Kong wet season is a gamble; upright rosemary on a slope or in a terracotta pot is a certainty.
The Mediterranean tree palette for Hong Kong is narrow but reliable. Olea europaea (the olive) is the obvious choice: it tolerates humidity better than most Mediterranean trees, develops character quickly, and looks precisely as good in a minimalist Shek O terrace as it does on a Tuscan hillside. The dwarf cultivar ‘Little Ollie’ is fruitless and compact, suitable for large containers. Punica granatum (pomegranate) is equally tough, produces flowers of an almost offensive orange-red, and will fruit in Hong Kong if given a hot, sheltered position. The double-flowered forms like ‘Madame Legrelle’ are sterile but floriferous; the single forms will give you fruit if you are patient.
Australian Plants: The Underrated Powerhouse
If Mediterranean plants are the obvious reference for a Hong Kong dry garden, Australian plants are the smarter one. The continent’s climate runs from tropical monsoon in the north to cool-temperate in Tasmania, but the zone most relevant to Hong Kong is the southwest corner of Western Australia and the coastal regions of South Australia and Victoria — places that receive their annual rainfall in a winter deluge and then spend six months under a baking sun.
Australian plants have been criminally underused in Hong Kong. The nursery trade has favoured the familiar — Ixora, Hibiscus, Bougainvillea — over the genuinely suited. This is a mistake. Many Australian species not only tolerate Hong Kong’s conditions but actively thrive in them, producing flowers of a complexity and strangeness that make a Hibiscus look like a child’s drawing.
Grevillea is the genus to start with. These are shrubs from the Proteaceae family — cousins of the South African proteas and leucadendrons — and they produce flowers that look like someone described a bottlebrush to a surrealist. Grevillea ‘Robyn Gordon’ is the most reliable cultivar for Hong Kong: it flowers almost continuously, tolerates heavy summer rain if the drainage is adequate, and reaches about 1.5 metres in both height and width after three years. It wants full sun, acid to neutral soil, and — critically — no phosphorus. Australian Proteaceae have evolved in phosphorus-poor soils and will turn yellow and die if fed a standard NPK fertiliser. Use a native-plant fertiliser with a phosphorus content below 3%, or simply don’t feed them at all. They prefer neglect to the wrong food.
Westringia fruticosa (coastal rosemary) is the Australian answer to the Mediterranean rosemary problem. It looks similar — fine, grey-green leaves, small white to pale-lavender flowers — but it handles humidity considerably better. The cultivar ‘Smokie’ has variegated foliage that reads as silver from a distance. ‘Wynyabbie Gem’ is a hybrid with slightly larger leaves and a more arching habit. All of them respond well to clipping and can be maintained as a low hedge, which makes them useful as structural elements in a dry-garden scheme. Prune after flowering in late spring; a second light trim in September will keep them tidy through the wet season.
Callistemon (bottlebrush) is the easiest Australian genus for Hong Kong. The weeping bottlebrush, Callistemon viminalis, is already naturalised along Hong Kong’s stream banks and nullahs — a reliable indicator that it can handle both wet feet and dry spells. The cultivar ‘Little John’ is a dwarf form with blue-green foliage and blood-red flowers that reaches barely a metre in height, making it suitable for containers and small gardens. ‘Captain Cook’ is a medium shrub with a dense, rounded habit. All bottlebrushes want full sun and will flower more heavily if pruned immediately after each flush of bloom.
For colour in the dry garden, consider the emu bushes (Eremophila species). These are shrubs from arid and semi-arid Australia, which makes them almost comically over-prepared for Hong Kong’s worst summer. Eremophila maculata ‘Valentine’ produces deep pink, tubular flowers from late winter through spring; Eremophila glabra ‘Kalbarri Carpet’ is a low-growing form with silver foliage and yellow flowers, useful as a groundcover in full sun. The catch with emu bushes is that they demand perfect drainage. Plant them on a mound, in a raised bed, or on a slope. In flat, heavy soil they will die within a single wet season, and they will do it quickly enough that you will wonder what you did wrong. What you did wrong was plant an arid-zone shrub in a clay saucer.
The Gravel Garden: Beth Chatto’s Lesson Applied to the Subtropics
In 1991, the British plantswoman Beth Chatto converted the car park of her Essex nursery into a garden. She did not improve the soil. She did not install irrigation. She spread a thick layer of gravel over the compacted car-park surface and planted into it — drought-adapted plants from the Mediterranean, South Africa, and the Americas, species that had evolved to survive on rainfall alone. Nearly three decades later, that car-park garden has never been watered. It is one of the most influential gardens of the twentieth century.
The Chatto method translates to Hong Kong with modifications. The core principle — free-draining surface layer over moisture-retentive subsoil — works wherever rain falls in seasonal bursts. In Hong Kong’s context, the gravel layer is not just an aesthetic choice or a mulch. It is a rain shield. A 5-to-8-centimetre layer of 10-millimetre gravel or crushed granite prevents the soil surface from sealing under the impact of monsoon downpours, allows water to infiltrate gradually rather than pool, and suppresses the weeds that germinate explosively after every rain event.
The soil beneath the gravel matters more than the gravel itself. Hong Kong’s native soils range from decomposed granite on the Peak and in the New Territories to marine clay in the low-lying areas of Kowloon and the northern New Territories. Neither is ideal for a dry garden. Decomposed granite drains well but holds almost no nutrients; marine clay holds nutrients but drains like a blocked sink. The solution in both cases is the same: incorporate at least thirty percent by volume of coarse, sharp material — 5-to-10-millimetre granite chips, expanded shale, or coarse river sand — into the top thirty centimetres of soil. Do not use builder’s sand. Builder’s sand is fine and rounded and will turn your planting bed into concrete. Sharp sand, the kind sold for concrete mixing, has angular particles that create air pockets and drainage channels.
The gravel layer is not decorative. It is a rain shield — absorbing the impact of monsoon downpours, preventing surface sealing, and giving water time to infiltrate rather than runoff.
For the gravel itself, use locally sourced crushed granite. It is cheaper than imported stone, visually consistent with Hong Kong’s geology, and — unlike limestone gravel — will not raise the soil pH over time. A 10-millimetre grade is the sweet spot: large enough to stay in place during the heaviest rain, small enough to walk on comfortably. Avoid pea gravel. Pea gravel is round, moves underfoot like ball bearings, and looks like a 1990s shopping-mall planter. Use crushed angular gravel or don’t use gravel at all.
Plant Selection: The Dry-Garden Palette
The dry-garden plant list is longer than most Hong Kong gardeners assume. The constraint is not the number of suitable species but the nurseries’ stubborn insistence on stocking the same thirty plants they have stocked since 1985. You will need to hunt. The flower market in Prince Edward is the starting point, but the better finds are at the specialist growers in Fanling and Sheung Shui, several of whom will propagate to order if you ask politely and are willing to wait a season.
The structural plants — the bones: Agave attenuata (foxtail agave) is the easiest sculptural plant for Hong Kong. It has no spines, grows quickly, and produces offsets freely enough that a single plant becomes a colony within three years. Plant it on a slope or in a raised bed; it will rot in heavy, level soil. Agave parryi is slower, more compact, and strikingly blue-grey, with fierce terminal spines that make it unsuitable for gardens with small children but superb as a focal point. Yucca gloriosa ‘Variegata’ provides vertical structure with cream-edged leaves and will flower — a tall spike of waxy white bells — after about five years in the ground. Dasylirion longissimum (Mexican grass tree) is a sphere of fine, radiating leaves on a slowly elongating trunk; it looks like a fibre-optic lamp from the 1970s in the best possible way.
The flowering shrubs — the colour: Polygala myrtifolia (September bush) from South Africa produces pea-like purple flowers year-round in Hong Kong and never seems to stop. Plumbago auriculata (Cape leadwort) is a scrambling shrub with clusters of pale sky-blue flowers; it will cover a fence or a trellis in a single season and flower from April through November. Cut it back hard in December. Teucrium fruticans (tree germander) has silver foliage and lavender-blue flowers; it makes an excellent low hedge that requires clipping only twice a year. Leonotis leonurus (lion’s tail) produces whorls of orange, tubular flowers in late summer and autumn on stems that can reach two metres; it dies back to the ground in winter and returns from the base in spring. Cut the dead stems to the ground in February.
The perennials and grasses — the texture: Gaura lindheimeri (now Oenothera lindheimeri) is a perennial with wand-like stems of white or pink flowers that move constantly in the slightest breeze. It flowers for months, self-seeds gently, and wants nothing more than full sun and indifference. Nepeta (catmint) is the Mediterranean answer to lavender for those who have killed too many lavenders: it produces a haze of lavender-blue flowers from spring through autumn and will survive in heavier soil than lavender tolerates. The cultivar ‘Walker’s Low’ is misnamed — it reaches 60 centimetres — but is reliably long-flowering and responds to a mid-season shear with a second flush. Nassella tenuissima (Mexican feather grass) is a fine-textured, blonde grass that catches every movement of air and turns gold in autumn. In Hong Kong, it is likely to be short-lived — treat it as a biennial and let it self-seed. Muhlenbergia capillaris (pink muhly grass) produces clouds of pink inflorescences in late autumn that look like cotton candy rendered in botanical form. It needs full sun and well-drained soil but is otherwise undemanding.
The succulents and groundcovers — the skin: Drosanthemum and Delosperma (ice plants) from South Africa form carpets of fleshy leaves covered in daisy-like flowers of magenta, yellow, or white. They are excellent for covering the soil between larger plants in full sun. Senecio serpens (blue chalksticks) is a low, spreading succulent with chalky-blue, finger-like leaves; it roots where it touches the ground and forms a dense mat within a season. Sedum species, particularly Sedum rubrotinctum (jelly bean plant) and Sedum nussbaumerianum (coppertone sedum), add warm tones of red, copper, and bronze to the dry garden’s predominantly silver-green palette.
Watering: The Counter-Intuitive Rules
The dry garden is not a no-water garden. It is a garden that receives water on the plant’s terms, not on the gardener’s schedule. The distinction matters.
Newly planted dry-garden specimens need consistent water for their first season — not because the plants want it, but because their root systems have not yet extended into the surrounding soil. A Grevillea planted in April needs watering every three days through its first summer. By its second summer, it should need water only during extended dry spells. By its third, it should need nothing except rain. This is the trajectory: water is a tool for establishment, not maintenance.
The time of day matters more than the quantity. Watering at 6 a.m. allows moisture to reach the root zone before the sun pulls it back out; watering at 6 p.m. leaves the soil surface damp through the night, encouraging the fungal pathogens that kill more dry-garden plants than drought ever does. The rule is inflexible: morning water only. If you cannot water in the morning, water the following morning. A plant that goes an extra twelve hours without water is at less risk than a plant that sits in damp soil through a humid Hong Kong night.
Overhead watering — the sprinkler, the hose waved over the border — has been unfairly demonised. The argument against it is that water on foliage encourages fungal disease, and this is true for plants like roses and tomatoes in humid climates. But dry-garden plants, particularly those with silver or hairy foliage, have evolved to channel water down their leaves to their roots. Overhead watering mimics the rain pattern they evolved with. The real problem with overhead watering is not the plants; it is the waste. In a Hong Kong summer, thirty to forty percent of water sprayed into the air evaporates before it touches soil. Drip irrigation is more efficient, but a hand-held hose with a trigger nozzle, applied directly to the root zone, is better than either. You cannot automate care. You can only delegate it to equipment, and equipment does not notice when a plant looks thirsty.
A plant that goes an extra twelve hours without water is at less risk than a plant that sits in damp soil through a humid Hong Kong night. Morning water only. The rule is inflexible.
Designing the Dry Garden: Composition Before Collection
The most common failure mode in dry gardening is not horticultural but compositional. A gardener discovers the dry-garden plant palette, acquires one of everything, and arranges them like stamps in an album: one Agave, one Grevillea, one Westringia, spaced evenly, each alone. The result is a plant collection, not a garden. A garden is a composition. A collection is a shopping list with roots.
The dry garden, because it uses plants with strong architectural forms — rosettes, spikes, spheres — benefits from massing and repetition. Three identical Agave attenuata planted in a loose triangle read as a statement. One reads as a specimen that got lost on the way to a larger garden. Five Westringia planted in a drifted row, their forms merging into a single silver-grey mass, create the kind of ground-plane that makes the individual specimens — the Grevillea, the Dasylirion — read as events. The dry garden is at its best when it is composed the way a florist composes an arrangement: a framework of structural foliage, a middle layer of flowering forms, a haze of fine-textured filler plants to soften the transitions.
Height is the hardest dimension to get right. Dry-garden plants are predominantly low to medium shrubs; without trees, the garden reads as a flat tapestry. A single small tree — an olive, a pomegranate, a Cercis canadensis (eastern redbud) if you can find one — provides the vertical dimension that makes the rest of the planting legible. The tree does not need to be large. A three-metre olive in a sea of knee-high shrubs is a landmark. Without it, the garden is a carpet.
Paths in the dry garden should be substantial. Gravel paths, 90 centimetres wide at minimum, edged with steel or stone. Narrow paths invite you to walk through the garden; wide paths invite you to walk in it. The distinction is psychological but real. A dry garden rewards slowness. The textures that make it work — the fine hairs on a Santolina leaf, the chalky bloom on an Agave, the individual florets of a Grevillea flower — are invisible at walking speed. A wide path and a bench are not luxuries. They are viewing infrastructure.
Maintenance: The Dry-Garden Year
A dry garden is not a low-maintenance garden. It is a different-maintenance garden. The tasks shift from the weekly — mowing, watering, deadheading — to the seasonal: a major cutback in late winter, a mulch refresh in spring, a weeding blitz after the first rains. The time commitment is roughly the same; it simply arrives in concentrated bursts rather than a steady drip.
Late winter (February): The major prune. Cut back the deciduous perennials — the Gaura, the Nepeta, the Leonotis — to within a few centimetres of the ground. Prune the Mediterranean shrubs: lavender, rosemary, Santolina, Teucrium. Do not cut into old, leafless wood on these plants; they will not regenerate from it. Leave a framework of foliage on each branch. Remove any dead or diseased wood from the Grevilleas and Callistemons. Cut back the ornamental grasses to 10 centimetres. This is the ugliest the garden will look all year. Photograph it anyway. The comparison with March will be instructive.
Spring (March–April): Top-dress the gravel mulch. Over the course of a wet season, gravel sinks into the soil and organic matter accumulates on the surface. Rake back the existing gravel in sections, spread a 2-centimetre layer of fresh crushed granite, and re-spread the old gravel on top. This sounds like make-work. It is not. The gravel layer is the garden’s primary defence against weeds and evaporation; it needs renewal. While you are at it, apply a slow-release fertiliser formulated for native plants — low phosphorus, with trace elements — to the Grevilleas, Banksias, and other Proteaceae. Feed the Mediterranean plants with a general-purpose organic fertiliser. Do not overfeed. A dry garden on rich soil produces soft, sappy growth that attracts pests and wilts in heat.
Summer (May–September): Water newly planted specimens only. Weed after every significant rain event — monsoon rain germinates weed seeds that have been dormant for years, and a single missed weeding in July produces a jungle by August. Remove spent flower heads from the Grevilleas and Callistemons to encourage repeat blooming. Check the drainage after heavy rain; if water is pooling anywhere, dig a small sump or install a gravel-filled drainage channel. Standing water in a dry garden is an emergency, not an inconvenience.
Autumn (October–November): Light prune on the Mediterranean shrubs that have grown leggy over the wet season. Collect seed from the grasses and perennials if you want to propagate. Plant new specimens now — the soil is still warm, the rains are tapering off, and the plants have six months of relatively mild weather to establish before the next summer. Autumn planting is always better than spring planting for dry-garden species.
Winter (December–January): The garden rests. Enjoy it. This is the season when the dry garden looks its best in Hong Kong — the light is low and golden, the temperatures are civilised, and the plants that sulked through August are now producing their best growth. This is also the season to plan. Walk the garden with a notebook. What worked? What died? What would you add if you had another three square metres? The answers you write down in January are more honest than the ones you will give in April, when garden-centre optimism has replaced winter realism.
The Honest Conclusion
The dry garden is not for everyone. It requires a gardener who can tolerate a certain amount of brown — the summer dormancy that turns Mediterranean shrubs grey and crisp at the edges, the Australian grasses that go blonde and brittle, the succulents that shrink and wrinkle. If the sight of a plant that is resting rather than dying makes you reach for the hose, the dry garden will make you anxious. If, on the other hand, you find something honest in a garden that does not pretend the climate is something it is not — that lets plants look tired in August because August is tiring — then the dry garden is the most interesting garden you can make in Hong Kong right now.
Start small. A single raised bed, two metres by one, built from recycled railway sleepers or off-form concrete blocks, filled with a fifty-fifty mix of good topsoil and sharp granite chips, mulched with crushed stone. Plant it with three Agave attenuata, five Westringia ‘Smokie’, a drift of Gaura in the front, and a Grevillea ‘Robyn Gordon’ as the anchor. Water it for the first summer. After that, let it be. Watch what happens. Take notes. In three years, you will either have a garden that makes your neighbours’ Ixora hedges look like the horticultural equivalent of beige wall-to-wall carpet, or you will have killed everything and learned more about drainage than you ever wanted to know. Either outcome is useful. Only one of them is a garden.
