This is an article from Curious Kids, a series for children. The Conversation is asking kids to send in questions they’d like an expert to answer. All questions are welcome – serious, weird or wacky!
Why are leaves green? – Indigo, age 6, Elwood.
The leaves of most plants are green, because the leaves are full of chemicals that are green.
The most important of these chemicals is called “chlorophyll” and it allows plants to make food so they can grow using water, air and light from the sun.
This way that a plant makes food for itself is called “photosynthesis” and it is one of the most important processes taking place on the whole planet.
One of the most important chemicals on Earth is called chlorophyll. It’s green and it allows plants to make food so they can grow. Marcella Cheng/The Conversation, CC BY-ND
Without photosynthesis there would be no plants or people on Earth. Dinosaurs would not have been able to breathe and the air and oceans would be very different from those we have today. So the green chemical chlorophyll is really important.
All leaves contain chlorophyll, but sometimes not all of the leaf has chlorophyll in it. Some leaves have green and white or green and yellow stripes or spots. Only the green bits have chlorophyll and only those bits can make food by photosynthesis.
All leaves contain chlorophyll, but sometimes not all of the leaf has chlorophyll in it. Marcella Cheng/The Conversation, CC BY-ND
If you’re really good at noticing things, you might have seen plants and trees with red or purple leaves – and the leaves are that colour all year round, not just in autumn.
These leaves are still full of our important green chemical, chlorophyll, just like any other ordinary green leaf. However, they also have lots of other chemicals that are red or purple – so much of them that they no longer look green. But deep down inside the leaves the chlorophyll is still there and it’s still green.
Even leaves that don’t look green have chlorophyll. However, they also have lots of other chemicals that are red or purple. Marcella Cheng/The Conversation, CC BY-ND
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Simon Lester goes out on a limb to identify species and stop us barking up the wrong tree.
Whether it’s a majestic oak or a wind-pruned thorn hanging on to life on an exposed coastline or a desolate moor, Britain’s trees are a truly remarkable and defining feature of our landscape.
Solemn, stately and statuesque, they have towered over our countryside for some 400 million years, offering breathtaking beauty, shelter, shade, fuel, food and the most versatile building material known to man. They are living documents of our very existence, which bring reassurance and hope through their indefatigable ability to outlive us.
Here’s our simple guide to identifying British trees.
- Common lime – Tilia x europaea
- English oak – Quercus robur
- London plane – Platanus x hispanica
- Common beech – Fagus sylvatica
- Scots pine – Pinus sylvestris
- Crack willow – Salix fragilis
- English elm – Ulmus minor var. vulgaris
- Field maple – Acer campestre
- Common hazel – Corylus avellana
- Holly – Ilex aquifolium
- Hornbeam – Carpinus betulus
- Horse chestnut – Aesculus hippocastanum
- Common alder – Alnus glutinosa
- Common ash – Fraxinus excelsior
- Aspen – Populus tremula
- Rowan – Sorbus aucuparia
- Sessile oak – Quercus petraea
- Silver birch – Betula pendula
- Sweet chestnut – Castanea sativa
- Sycamore – Acer pseudoplatanus
- Yew – Taxus baccata
- What Leaf Colors Do Oak Trees Have in Autumn?
- Shade-loving Plants
- Mona lavender
- Silver spurflower
- Sweet Box
- Camellia ‘Lady Gowrie’
- New Zealand rock lily
- Winter Daphne
- Oakleaf Hydrangea
- Kaffir Lily
- Giant mondo grass
Common lime – Tilia x europaea
Probably the tallest broad-leaved tree in Britain, the common lime is set apart from other limes by bushy side shoots that start from near the ground. Often seen in streets and parkland, this galleon of a tree is a true joy to sit beneath in July, when its sweetly scented flowers attract gently buzzing bees.
As well as feasting on the nectar and pollen, insects love to drink the honeydew deposited by aphids on the tree’s delicate, heart-shaped leaves, which have tiny tufts of white hair in the vein axils.
English oak – Quercus robur
Also called pedunculate oak, because it bears fruit or acorns on long stalks or ‘peduncles’, this is the most common oak in Britain. Set apart by its generous trunk, sturdy, crooked branches and expansive crown, the female flowers bloom on upright stalks, with the male equivalent appearing as hanging catkins.
Acorns develop, usually in pairs, next to alternate and distinctively scalloped stalkless leaves that have ear-like lobes at the base.
London plane – Platanus x hispanica
Brought here from Spain in the 17th century and planted for its ability to thrive in urban conditions (thanks to its bark, which sheds in large flakes, preventing the tree from becoming suffocated under sulphurous grime), the London plane is a hybrid of the Oriental plane and the American plane.
Its large, bright-green serrated leaves are up to 6in or more across, set alternately on the stem and not in opposite pairs. Ball-shaped male and female flowers flourish on the same tree, albeit on different stems. Once pollinated by the wind, the female flowers develop into bristly fruits.
Common beech – Fagus sylvatica
The mature beech—which can reach 130ft and develop a massive, many-branched dome—is a sight to behold, especially when it comes into bright-green leaf in May.
The dense canopy means only shade- tolerant plants can survive. However, this is made up for by the way splendid stands of these trees set the countryside ablaze in autumn, when their leaves turn orange, then rich red-brown. Both male (tassel-like) catkins and female flowers grow (in pairs, encased by a cup) on the same tree, which, once pollinated by the wind, houses beech mast.
Scots pine – Pinus sylvestris
Scotland was once covered by ancient Caledonian pine forest, but, now, only about 50,000 acres of these Tolkein-esque trees remain in the Highlands. Capable of reaching 115ft and living for 700 years, the trees’ scaly, warm-orange bark fissures with age.
Evergreen needles, which are shorter than those of other pines and have a blue tinge, are slightly twisted and grow in pairs on side shoots. Yellow male flowers appear at the base of these shoots and globular, blood-red tipped female blooms grow at shoot tips. Once pollinated by the wind, female flowers turn green and develop into cones.
Crack willow – Salix fragilis
Difficult to distinguish from the white willow, the crack willow—which likes to grow on lowland wet soils, particularly by water and in woods—is so called because of the sound its branches and twigs make as they snap and fall to the ground.
Its narrow, oval, elongated leaves are shorter than those of the white willow and it’s dioecious, with male and female flowers seen on sep- arate trees in May—male catkins are yellow and female catkins green.
English elm – Ulmus minor var. vulgaris
It seems ironic that the billowing, once widespread English elm used to be associated with melancholy and death (possibly because dead branches can fall without warning), only for it to be ravaged by Dutch elm disease in the late 1960s.
With double-toothed, round-tipped leaves, the elm’s blush-tinged, tassel-like flowers appear in February and March and, once pollinated by wind, become winged fruits called samaras that are cast forth in the breeze.
Field maple – Acer campestre
The field maple is Britain’s only native maple—and yes, its sap can be used to make syrup. Often spotted in hedgerows, it can be identified by the five, rounded lobes of its olive leaves—which fade to ochre in autumn—svelte twigs and light-brown, flaky bark.
Its flowers appear to be hermaphrodite, but they’re dominated by either male or female sexual parts, which are small, yellow-green, cup-shaped and hang in clusters. After pollination by insects, they become large, winged fruits, which are scattered by the wind.
Common hazel – Corylus avellana
Long believed to possess magical powers, the hazel is often coppiced, but can reach 40ft and live for up to 80 years. Long, pale-yellow catkins appear and shed their pollen in February, before toothed and hairy leaves unfurl.
The hazel’s tiny, female flowers, which are tipped with red stigmas and almost hidden within the leaf-buds, are pollinated by the wind and eventually mature into clusters of up to four brown nuts, each surrounded by jagged-edged green bracts.
Holly – Ilex aquifolium
Glossily evergreen, this much- loved conical-shaped tree, with its prickly, darkest-emerald leaves and bright-red berries (which only adorn female trees), has been used as a winter decoration since pre-Christian times. The thickness and waxy surface of its leaves help them to resist water loss and last up to four years on the tree, which explains how sprigs and wreathes can survive the festive season.
Seen as a fertility symbol and a charm against witches and goblins, cutting down a holly tree—which only has spiky leaves at the bottom to desist browsing animals—was considered unlucky.
Hornbeam – Carpinus betulus
Often confused with common beech, but the buds on winter twigs of hornbeam lie flat, rather than sticking out at a wide angle as with beech. A fluted trunk also distinguishes the tree, along with hanging clusters of triangular, ribbed nutlets ringed by long, three-lobed bracts.
Male (dangling catkins) and female (leafy buds) form on the same tree and, after pollination by the breeze, female catkins become green-winged fruits known as samaras.
Horse chestnut – Aesculus hippocastanum
Introduced to Britain from Turkey in the 1600s, the horse chestnut is more common in parks, gardens, along roads and on village greens than in woodland.
Towering up to 130ft and living as long as 300 years, it’s easily identified by its handsome palmate leaves comprising five to seven pointed, toothed leaflets and the arresting ‘candles’—spears of white blossom, with a pink flush at the base—that adorn it from May. Once pollinated by insects, each flower becomes a burnished red-brown conker encased in a spiky acid-green husk, which falls in autumn
Common alder – Alnus glutinosa
I’m fond of the dark-green, round- leaved alders that escort the rivers that wind down from the moor, below our house in the Scottish borders, en route to the Border Esk. One of the few trees on which leaves stay verdant well into the autumn, it’s the alder’s catkins that make it stand out from the rest of the trees in the wood. Although the fruits ripen in October, they remain throughout the winter as brown, woody cones, until the seeds are dispersed in spring.
Common ash – Fraxinus excelsior
The ash is one of our tallest trees, easily distinguished by fronds of 6–13 avocado-coloured toothed leaf- lets that sit opposite each other. Look out for short, black buds in opposite pairs on smooth, grey twigs.
The ash, on which spiked clusters of purple-tipped flowers usually appear on different trees, but, paradoxically, can develop male and female flowers on different branches of the same tree, is susceptible to ash dieback. Once pollinated by the wind, these flowers become winged fruits known as ‘keys’.
Aspen – Populus tremula
Also known as ‘quaking aspen’, possibly due to the way its small leaves—which are borne singly on long, flattened stalks—tremble in the breeze, creating a rustling sound, the aspen’s leaves are a coppery-brown shade when they first unfurl in spring, fading to amber in autumn.
With dainty trunks cloaked in silvery-green bark, often pitted with diamond-shaped pores called lenticels, individual aspens produce exclusively male and female flowers (catkins) in March or April, before the leaves appear. Fertilised female catkins ripen during the summer, before releasing tiny, tufted seeds.
Rowan – Sorbus aucuparia
The rowan is a graceful, open tree with smooth, grey-brown bark and pinnate (feather-like) leaves comprising eight pairs of long, oval and toothed leaflets. Its extreme hardiness— which means that, along with the silver birch, it can be found higher up on mountainsides than any other tree in Britain—explains why it’s sometimes known as the mountain ash.
Widely planted as a street or garden tree, it’s a hermaphrodite and comes into its own in May, when clusters of white blossom spread over the crown. By September, these have become the lipstick-red berries that make a great jelly to go with game.
Sessile oak – Quercus petraea
So-called due to its stalkless (sessile) acorns, Britain’s second native oak is usually found in less fertile upland areas. When mature, it forms a broad and spreading crown and tends to be taller, with a more elongated, straighter trunk, than an English oak.
Male and female flowers are found on the same tree, with male flowers forming green catkins and females appearing as discreet clusters of bracts (modified leaves), which resemble red flower buds.
Silver birch – Betula pendula
Easily recognisable as one of Britain’s native trees, thanks to its slender trunk and pearly-white bark, the silver birch grows higher up mountains than any other deciduous tree.
Its delicate leaves, with a straight base and large teeth, alternate along slim, whip-like, red-brown twigs and the branches usually droop downwards, hence the Latin name pendula, which means hanging. In winter, when viewed en masse from a distance, the naked branches of this feminine and graceful tree radiate a soft, purple hue.
Sweet chestnut – Castanea sativa
Widespread in coppices and park- lands, but rare in the North and West, the sweet chestnut has grown in Britain since Roman times. As cool British summers prevent nuts ripening, most chestnuts eaten in the UK are imported. Large, narrow trees with long and slim leaves, saw-like teeth and parallel veins and lots of low branches, sweet chestnuts punctuate parks or former parkland.
Unusually, its catkins bear mostly male flowers and others have both male and female—female flowers form at the base and tassel-like male flowers at the tip of the catkin, which in autumn, develops into a spiky husk containing up to three nuts.
Sycamore – Acer pseudoplatanus
Introduced from France in the Middle Ages, the sycamore is a common sight in woodlands and gardens. Set apart by its winged fruits, which, in October spiral to the ground rather like helicopter blades, this tree—with a massive domed outline and dense foliage—is also distinguished by its dark green, leathery-like toothed leaves, which don’t look unlike those of the maple. Greenish-yellow flowers appear, along with the leaves, in May and June.
Yew – Taxus baccata
Long associated with churchyards, the yew can reach 600 years of age, with some British specimens pre-dating the 10th century. A symbol of immortality, but also a harbinger of doom, the yew has small, ramrod- straight needles with pointed tips that grow in two rows on either side of each twig.
Male and female flowers—which grow on separate trees—appear in March and April. The yew doesn’t bear its seeds in a cone; each seed is enclosed in a red, fleshy, berry-like structure known as an aril, the only part of the tree that’s not toxic.
If you liked our simple guide to identifying British trees you might also like:
What Leaf Colors Do Oak Trees Have in Autumn?
Several factors contribute to an oak tree’s show of fall foliage when autumn rolls around. Though some factors like temperature, rainfall and sunlight are out of your control, the type of oak tree you plant in your yard also has an effect on the foliage colors you can expect to see. Oak trees may not boast the striking bronze and maroon color of maple trees in fall, but they do provide a range of hues to add color to the fall landscape.
Red is one of the most dramatic and distinctive colors of the fall landscape, particularly against a horizon of lighter shades like yellow or orange. While maple trees may be better know for their striking red fall foliage, some varieties of oak trees also sport the rosy-hued flora. Both the eastern white oak and the aptly-named scarlet oak display bold red leaves in the later fall months. The broad spectrum of potential shades of red range from brick red to more deep and elegant scarlet reds.
Though less dramatic than bold red, russet-colored oak leaves are one of the hallmark foliage colors for many oak species. Russet is warm brown with red undertones; it is less a muddy brown and more of a bronze-like red. The pin oak and scarlet oak are known for displaying the distinctive russet leaves. Though not as glamorous as other colors, one of the values of russet leaves is that they tend to display later in the season, providing color when most other leaves have given way to bare branches.
Not all oak foliage colors are dark and dramatic. Some oak varieties sport the sunny yellow leaves often found on other species like beech or birch trees. The yellow spectrum of color for oak varieties like red oak and English oak tend to be tinted with darker hues like brown or red, distinguishing them from their bright yellow counterparts.
One variety of oak that offers an unusual foliage color is the white oak which sports a leaf shade of burgundy purple during the foliage season. The white oak’s purple leaves tend to be less bold than the royal purple seen on some dogwood species, but the shade is still distinctly different than the more subdued russet and red shades of other oaks. White oak trees are particularly finicky about climate conditions; officials at the Iowa Department of Natural Resources warns that the purple hue readily transitions into a much duller shade of brown.
Nearly every garden has a shady corner or a dark patch that gets little or no sun, whether it’s a border enveloped in shade from the shadows of a house, usually on the south side of your home, a big tree, shed or fence blocking the light, or a balcony that doesn’t receive much sun, it’s a problem many gardeners face.
These parts of the garden can be some of the most challenging spaces to grow plants in, particularly in full shade. However, as plants are the ultimate niche-fillers in nature, there are many plants readily available that are suitable for growing in varying levels of shade. Before you make your selection, it’s important to assess the light conditions you will be planting in, as there are many degrees of shade:
- Full shade – This means no direct sunlight reaches this part of the garden. This is the most challenging environment to grow in.
- Semi or partial shade – This type of shade is when an area gets sun for only part of the day. Plants can be very fussy, and the time of day they receive sunlight can impact growth and survival, particularly with the temperature changes and differing light the time of day brings. So, ensure you know whether it’s morning or afternoon sun your garden receives before choosing your plants.
- Light or dappled shade – This is an area that receives filtered sunlight during the day, usually under a tree with foliage that is not too dense.
Many of the best shade-tolerant plants can be identified by their lustrous, deep green foliage although not all follow the rule. Here are some fantastic choices to brighten up those shady spaces:
This beautiful member of the Plectranthus family is a neat, low-growing, rounded shrub that flourishes with spikes of vibrant lavender-purple blooms floating above deep green ornamental leaves with intensely purple undersides. This fast-growing shade-lover thrives in containers and is very easy to grow, best propagated from cuttings. The tough plant is versatile and will reside happily in full or half shade outside or as an indoor plant, only requiring water every few days to keep the soil consistently moist but not waterlogged.
• Grows to about 80cm tall
• Likes full or partial shade
• Happiest in fertile, well-drained soil
• Flowers from late summer through to late autumn
• Herbaceous, perennial shrub
The species of flowering plant belongs to the mint family and is native to the border region of Queensland and New South Wales. With large velvet-like grey leaves and spikes of small mauve and white flowers in autumn, this hardy shrub is well-suited to growing in shade. Silver spurflower is a vigorous spreading plant, so may be better suited to growing in a container if you don’t want it to take over your garden bed. It’s fairly drought tolerant too, making it a good all-rounder.
• Grows up to 100cm tall
• Likes partial or dappled shade
• Happiest in moist but well-drained soil
• Flowers in autumn
• If kept well trimmed it will remain dense
• Cannot tolerate frost
This medium-sized hardy evergreen shrub bears dark glossy green foliage and clusters of small ivory flowers that bloom in winter. Perfect for trimming into a low hedge, sweet box is a compact, hardy plant that can tolerate poor weather and light conditions. The shrub likes regular watering, rich soil and needs little else, rewarding gardeners with a display of fragrant flowers in winter.
• Grows slowly up to 2m tall
• Likes partial to full shade
• Needs rich, well-drained soil
• Flowers in winter through to spring
• Evergreen shrub
• Red, purple or black berries follow the flowers
Camellia ‘Lady Gowrie’
Camellia x Williamsii
Boasting large showy fuchsia blooms, this striking flowering shrub is suitable for growing in beds and containers and will grow happily in partial shade. A hybrid between a camellia japonica and a wild camellia called camellia sasanqua, this hardy shrub is drought-tolerant once established, renowned as the queen of winter as it’s among the most cold-hardy camellias. Best grown in consistently moist, well-drained soil protected from cold, dry winds.
• Grows up to 3m tall with a 1.8m spread
• Likes partial shade
• Happiest in slightly acidic, well-drained soil
• Flowers from late winter through to mid-spring
New Zealand rock lily
A hardy evergreen perennial originating from New Zealand, this plant’s beautiful year-round blue-green foliage and striking star-shaped white flowers appearing in summer make an elegant sight in the garden. New Zealand rock lily is a clumping plant that creates a lush tropical effect in the yard, thriving in partial shade or full sun, suited to containers and dry shady areas.
• Grows up to 100cm tall
• Likes partial shade or full sun
• Happiest in well-drained soil
• Flowers in summer
• Ideally needs to be planted en masse for full effect
Best suited to the cooler parts of Australia, the compact winter daphne plant is famed for its sweet fragrance and showy pink and white flowers that bloom in winter. At home in dappled shade, in pots or grown in the ground, daphne can be a little fussy about its growing conditions. If sown directly into the ground they require excellent drainage and a cool, sheltered spot, with light pruning and infrequent watering – they are prone to root rot so shouldn’t be left to stand in water at any time. It’s best to water and leave the soil to dry out each time before re-watering. Mulch well to keep the roots cool.
• Grows up to 150cm tall
• Likes dappled shade
• Happiest in moist but very well-drained soil
• Flowers in late winter through to early spring
• Red berries follow the flowers
The oakleaf hydrangea’s spires of densely-packed white lacy blooms put on a display throughout summer in Australia, popping in contrast to the plant’s large apple-green leaves. Hardy to extreme weathers, this hydrangea is best planted in a sheltered, shady position with cool, moist soil for it to thrive. Available in single and double blossom varieties, the oakleaf gets its name from the distinct shape of its leaves.
• Grows up to 150cm tall
• Likes partial shade
• Thrives in moist but well-drained soil
• Flowers in summer
• Can be deciduous or evergreen
This almost unkillable plant from the Amaryllis family promises to brighten up any outside space with their clusters of vibrant trumpet-shaped flowers that bloom in shades of orange, red and yellow come spring. Held on stalks above long dark green leaves, the plant is also known as bush lily and originates from South Africa. It grows exceptionally well in most parts of Australia, from warm to cold climates. Ideally planted in clumps, fire lilies like a full or partial shady position, i.e. beneath a tree.
• Grows up to 50cm tall
• Likes full or partial shade
• Happiest in well-drained soil
• Flowers in spring through to summer
Giant mondo grass
Though referred to as a grass this plant is actually a lily and can completely transform bare or stark areas of the garden, softening a harsh space with its neat clumps of shiny dark green leaves. It grows particularly lush in shaded spaces and flowers in summer with elongated flower spikes laden with creamy white blooms.
• Grows up to 75cm tall
• Likes partial to full shade
• Happiest in well-drained soil
• Flowers in summer
• Ideally needs to be mass-planted for full effect
• Blue berries will follow the flowers
There’s a whole range of beautiful plants to choose from for shady locations that are going to give you contrasting textures, a variety of foliage, colour and flowers to boot. To help you with watering these shade-loving plants we suggest using our reliable Retractable Hose Reel, available with a choice of hose lengths. We also have a wide variety of gardening tools perfect for digging, cultivating the soil, weeding, planting and much more. Our full gardening range can be viewed here.
NB This article has been written for Australian gardens. If you’re reading this from around the world, we do hope you’ve found it a useful stepping stone for your own further research.