Variegations on a Theme

It seems a long time since we spent two delightful weeks in late August in the furthermost corner of East Anglia cruising the Norfolk Broads, interrupted by only one day of showers. While the rivers remained navigable, the Broadland villages were left very short of water for their beautiful gardens over some ten weeks or more. I lost count of the number of dry, virtually leafless ornamental trees and shrubs – yet certain shrubs were coping far better than others- especially some which I had imagined would fry in full sun. Walking around a village often reveals patterns in planting- where neighbours may have shared cuttings, or plant stock in local nurseries had been limited, or garden plants had “escaped” to another local site by seed distribution. Even the village hedgerows contained their own (largely overlooked) varieties of plum, apple and Mirabelle which provided rich pickings for our foraging forays.

But what of the few survivors of drought? It seems that many garden “toughies” tend to go unnoticed, possibly because they are often dismissed as the “backbone” shrubs which are typically used to screen off, divide up or create backdrops for their more floriferous or whimsical cousins. But my interest was drawn towards the variegated varieties of bog-standard hedging evergreens, which were thriving against the odds.

Usually, variegated varieties are fussier than their “green” cousins because the leaf variegation (technically, two or more colours) is caused by a lack of chlorophyll. The foliage may be striped, blotched, edged, mottled etc. This effect is either caused by a virus – such as a mosaic virus like we see on cucurbit leaves- or by cell mutation. Indoor plants displaying interesting variegation can be very expensive because they are difficult to propagate; a variegated Swiss cheese plant, or an even rarer variegated pink philodendron, will cost many times more than a non-variegated equivalent. Variegated plants typically need more sun than their green counterparts because the lower levels of chlorophyll make it harder to photosynthesise in poor light. However, several other factors are important: for example, whether the underlying species typically thrives as a drought tolerant sun worshipper (perhaps not!), or how well it can adapt to a sharp change in temperature or humidity. Although plenty of light is needed, many struggle in day-long hot sun (especially when getting established). If a variegated plant is stressed it will either die or attempt reversion simply to survive – putting out new, plain green growth which unless nipped out will eventually take over. So although highly attractive, variegation is an unstable feature requiring optimal conditions to keep it that way.

I had long been seeking ways to both lift and colour the north facing edge of our woodland garden with shade tolerant shrubs, and to plant something similar on the warmer side to balance to pull the overall look together- otherwise the north and south borders would be so different as to split the garden in half. From observing what has thrived in Norfolk (or more precisely, where), I think it possible to achieve this outcome using the variegated forms of unfussy, tough shrubs which are often used as hedging or “backbone” planting. The tendency to reversion should in theory be less of a risk if the plants are naturally more resilient to change. During the hot Norfolk summer, some of these – including some attractive dwarf varieties - had clearly performed well. The foliage colours can range from pale creams and pinks through to reds, golds, yellows, and emerald and blue; many also change colour throughout the growing season, picking up shades of pink, scarlet or bronze later in the year. Many variegated shrubs are evergreen (or semi-evergreen, dropping leaves during a harsh winter and growing again in Spring)- offering winter colour when all else is bare.

Given that shrubs are best planted in the cooler months, now is a good time to think about adding one or two variegated varieties if you have room and inclination. When selecting any shrub, this is my basic checklist:

· Size. Most shrubs can be kept manageable by pruning – but it’s an annual maintenance job to add to someone’s list. There are an increasing number of dwarf varieties reaching 0.5- 1m in height/ girth, useful for small spaces and more manageable. Also consider the rate of growth when choosing the size of plant to buy; while a newly planted large shrub will need more time and care to settle in than a smaller one, slow growth requires patience.

· Aspect. Although variegated varieties need good light, prolonged hot sun may prove too much. But inadequate light can also stimulate reversion, because green leaves can make better use of available sunshine. When siting, avoid the hottest and shadiest areas – and remember to check where a variegated shrub sits in relation to other plants/ trees.

· Soil and moisture. Most are tolerant of a wide range of conditions. However, a few prefer acidic soil, damper or drier or better drained than average conditions.

· Colour. There are many more leaf textures, shades of green, and variegated colour combinations than just green and white. Look at the seasonal changes, too.

· Prickliness. Variegated holly, berberis and other hedging shrubs may be tough, attractive and keep out intruders, but they can also hurt pets, children, and sight-impaired individuals (especially if dead leaves and prickles are not swept up) so are best planted away from lawns, paths and seating areas.

· Plain or fancy? Many shrubs can be topiarised (clipped into shape), grafted, or grown as a standard (lollipop) tree. Standard-grown variegated euonymus, holly or “flamingo” willow can look stunning either in containers near an entrance, or to add height in a border. [Hint: if you decide on topiary, do attend a course to learn how to do it well. Topiarised specimens can be very expensive and are easily ruined by a wrong cut or (even worse) disease spread by your own secateurs.] Do remember that the stem or trunk of a grafted shrub will not grow taller with time; it will merely bush out above the graft.

· Berries. If you want berries for the birds, you may need both male and female plants growing near one another – this is especially true of holly (ilex). There are many more shrubs that happily produce berries on their own. Again, site away from paths and benches.

· Plant growth and leaf maintenance requires the process of photosynthesis, where light energy is converted into chemical energy that can be used by the plant. Evergreen trees and shrubs usually grow more slowly than deciduous plants, but they can keep photosynthesising during the winter, retaining their leaves and often flowering earlier than deciduous plants (camellias and azaleas are good examples). Most conifers are also evergreen. However - photosynthesis requires access to water; in winter, long spells of frozen ground water could pose problems. Similarly, camellias, azaleas and other spring-flowering shrubs require a good supply of water during late summer and autumn to help form their flower buds. So if you want a garden with year-round interest, do incorporate some evergreens but don’t overlook their need for water during extremes of hot and cold.

· Rabbit/ Deer resistance. Unfortunately, neither can read plant labels and if hungry they will try anything. However- thick and shiny/ furry/ prickly/ aromatic leaves are less palatable. Mature shrubs (more bitter/ toxic) are less prone to attack; while they can take longer to establish, planting a larger shrub can be safer. Protect new shrubs if in doubt.

· Finally, cost is a consideration given that variegated varieties can be more expensive than their green cousins. I’d suggest checking very carefully before planting, to ensure that your variegated tree or shrub has the happiest of homes.

Some variegated trees and shrubs to consider

Abelia Grandiflora “Kaleidoscope” and “Tricolour Charm”. These are unfussy semi-evergreen shrubs producing small white trumpet flowers throughout midsummer. “Tricolour Charm” is a dwarf variety (1m) with pastel leaf shades of green, cream and pink. “Kaleidoscope” (1.5m) has pale pink flowers against dramatic paint-box leaf colours changing with the seasons – green, gold, orange, and red. “Sunshine Daydream” (1m) is similar but smaller.

Acers. The Variegated Norway Maple (Acer platanoides Drummondii) is a big, beautiful tree (12m). Its classic maple shaped leaves are cream, edged in green. However, it can quickly show signs of reversion in inadequate light, and this must be dealt with promptly.

Japanese Acers (acer palmatum/ acer dissectum) are already popular for the changes in foliage colours throughout the year, but variegated varieties are also much sought after. “Yama Nishiki”, “Beni Schichihenge”, “Kotobuki” and “Ukiguomo” are each remarkably beautiful, combining variegation with seasonal colour change. If you invest in a variegated acer, note that the siting and cultivation for each could be slightly different.

Acuba Japonica Crotonifolia – Japanese Spotted Laurel. This is a large, tough, evergreen shrub capable of surviving almost anywhere except waterlogged ground. It has large bright green leaves dotted or splashed with yellow. One for a dull or difficult location, it is most grown as a hedge but a single specimen can lift a shadier corner.

Caryopteris Clandonensis – “White Surprise” bluebeard. This is a beautiful deciduous shrub producing intermittent whorls of fragrant blue flowers on long stems (1m) in late summer, just when the borders can begin to lack vibrance. The leaves are green/ white and are sufficiently aromatic to deter deer and rabbits. A similar variety “divaricata Snow Fairy” is smaller and broader. “Summer Sorbet” (1m) has green/gold leaves which provide a colourful backdrop to the blue flowers. Prune back and feed in spring.

Cornus (dogwood) – some of the luminous- coloured bark varieties are variegated, including “Alba Elegantissima” (red-barked with white-edged sage green leaves) and “Sibirica Variegata” which has better leaf variegation but less vibrant red bark. “Sanguinea Variegata” has less attractive bark and is prone to suckering- so not ideal for tidy gardens!

The Wedding Cake Tree “Cornus Controversa Variegata” is spectacularly pale-leaved and tiered if you have room for a centrepiece tree.

Of the tall shrubby Chinese Dogwood varieties I would suggest looking at the Cornus Kousa varieties “Wolf Eyes”, “Lorna”, “Samaritan, “Summer Fun” and “Milky Way”; they have stunning large white flowers, some pink-centred- but need the right care to do well.

Elaeagnus (oleaster or silverberry). Full sun to light shade with good drainage. Hardy evergreen. Drought tolerant once established. Small, highly fragrant flowers in autumn. Variegated varieties include Ebbingei’s “Gilt Edge” (green/lime, 3-4m); Pungens Maculata (bright green leaves with irregular darker edges, 4-8m); Limelight (bright green leaves with darker streaks, slightly frosted, 2.5- 4m).

Euonymus – there are several variegated varieties of the humble spindle, all of which are very resilient, colourful and easy to maintain. They are semi-evergreen and suitable for hedging or within a mixed planting scheme. I have even seen these grown into stunning topiarised standard trees (topiary requires evergreen shrubs that easily “sprout” foliage).

Fortunei hybrids - “Emerald and Gold” (flushed bronze in winter) and “Dan’s Delight” (white/green) provide colourful ground cover. “Harlequin” (0.8m) appears more white than green. “Emerald Gaiety” (1.5m) is rich emerald green/white with an attractive pink flush in cold weather.

Japonicus hybrids - “White Spire” is an upright dwarf (0.4m) shrub with emerald and white foliage, ideal for brightening a small space. “Bravo” can top 2.5m with green/gold foliage.

“Ovatus Aureus” is also large, but the rounded leaves are more gold than green. “Himalaya” (1m) produces pure white foliage which matures to green/white, giving a two-tiered “candle” effect after pruning.

Hebe (Veronica) - these are low maintenance, evergreen shrubs needing good drainage. The variegated varieties tend to be dwarf, making them ideal for the path edge, rockeries and containers. Kept well-watered while establishing, they become fairly drought tolerant but require frost protection in cooler climates. “Variegata Speciosa” (max 1m) has grey-green /cream- margined leaves which take on a pink tinge in colder weather. “Silver Queen” (1m, aka “Fransiscana”) has more rounded dark green/ cream-margined leaves. “Heartbreaker” (0.6m) has more elongated two-tone leaves which turn a strong pink. Closely related, the leaves of “Frozen Flame”(0.6m) take on a bright magenta tinge, and “Purple Shamrock” a deeper shade of purple. All produce spiky lavender-coloured flowers which are attractive to butterflies. “Red Edge” has white flowers and dense blue-grey foliage turning red at the margins in cold weather.

Nandina Domestica (heavenly or sacred bamboo) is a small bushy deciduous shrub with bright bamboo-like foliage, usually maturing from red/pink/cream/or lime to a deeper green, generating a colourful tiered effect. Related to Berberis, Nandina is not a bamboo and is non-invasive; most grow to a compact 1m or less. “Firepower” is a dwarf variety which is very colourfully variegated especially in summer. “Twilight” leaves emerge pale pink/ bronze and mature to a variegated green (similar to a Flamingo willow). A very impactful foliage plant even in a small space or container, they need plenty of sun and drainage.

Osmanthus Heterophyllus Variegatus – the variegated holly olive is a dense evergreen shrub growing to 1.5m. The leaves are prickly dark edged with cream. It dislikes cold winds but is otherwise hardy and resilient. The small white flowers in late summer smell of jasmine.

Photinia “Pink Marble” is a large (4m) evergreen shrub which, like all photinias, puts out new red-pink foliage. With this variety, the leaves mature into green with white margins. Periodic pruning can therefore create a highly attractive triple-coloured specimen hedge or shrub. However, it can be frost-sensitive and a hungry feeder. Choose a sunny, sheltered position.

Pittosporium Tenuifolium Variegatum (lemonwood). Unfussy hardy evergreen. Black stems with light grey-green cream, pink-tinged leaves. Small fragrant purple flowers (May-June). Max height 4m x 2.5m. The variety “Gold Star” (2m) has glossy, bright green-gold leaves.

Pieris japonica “Little Heath” – this is a dwarf (0.7m) evergreen shrub with slender cream-margined leaves. New foliar growth in spring is flushed pink red, with arches of bell-shaped creamy lily of the valley flowers. It requires ericaceous (acidic) soil to thrive well. “Polar Passion” is similar, except the flowers are a deep dusty pink.

Weigela Variegata “Nana” – I have planted two of these recently in a dappled sunny border. Weigela is a much-overlooked deciduous shrub available with different coloured flowers. This variegated variety has green/white leaves and small, azalea-type flowers in pale pink, still in flower. It needs a prune to keep it in shape but is otherwise undemanding.

Useful links

An interesting encyclopaedia of over 700 variegated plants, for under £10 from Amazon

Crocus have over 580 variegated trees, shrubs and perennials for sale, many at 30% discount:

Gardening Express also have an impressive selection of variegated shrubs, standards and perennials at bargain prices:

Finally, a special mention about Hedges Direct, where I bought a pallet of specimen-sized variegated shrubs at keen prices with first-rate delivery. They currently have some sale stock.

Sian Lloyd, 27^th September 2022