Keith’s Favourite Shrubs
Ornamental shrubs in the garden are the bridge between trees and perennials forming the middle layers in mixed beds and borders. Like trees they develop hard, woody material with age but unlike trees many of these branches grow from a short stem or directly from the ground and not from a trunk. This means that shrubs can range from carpeting plants such as Heathers and some Cotoneasters all the way through to large specimen plants such as Buddlejas and Camellias.
Shrubs can offer so much to the garden coming as they do in all shapes, habits and sizes. The flowering and fruiting shrubs apart from the interest they give the gardener are very attractive to insects, birds and mammals and shrubs can provide flowers in every season of the year. Evergreen shrubs are particularly valuable in the winter providing again interest for the viewer as well as protection and shelter for wildlife. Shrubs are also extremely versatile with some making excellent specimen plants for lawns or beds, others combining well with perennials, climbers and trees in mixed plantings and being suitable for the whole range of growing conditions and soils. Their different habits also allow them to make a significant contribution to garden design. Horizontally extending branches such as with Viburnum plicatum ‘Mariesii’, arching or weeping growth as with Brooms (Cytisus) and those with an upright habit such as Viburnum sargentii ‘Onondaga’ can all play a part in creating pleasing architectural effects.
It wasn’t easy to reduce my list to a sensible number and I have made the choices a little easier by not including plants which really require whole blogs of their own. In this group I would include the wonderful Rose, the Japanese Acer and Climbing plants in general.
In the end I have reduced an enormous list down to a top 12 which I wouldn’t want to be without although every time I look at the list I want to add more! I have also chosen plants which are readily available in garden centres and nurseries and I have arranged then alphabetically to avoid having to put them in order! I have also tried to include plants which offer the gardener several attractive features such as flowers and good autumn colour or interesting leaves and colourful bark so that they really earn their place in the garden. Apologies if I have missed out some of your favourites! My list contains 5 evergreens, 4 deciduous and 3 which contain examples of both.
1 Berberis
This genus consists of both evergreen(E) and deciduous(D) species and cultivars. Most have small, spiny leaves with prickly stems and branches and in spring produce masses of yellow-orange flowers much loved by bees and followed by small, blue-black fruits. They are generally slow growing and trouble free and as a result need little, if any, pruning. Berberis darwinii (E) has small, holly-like leaves, dark orange flowers in spring and blue-black fruits, B. thunbergii(D) eg ‘Rose Glow’ and ‘Helmond Pillar’ have red-purple foliage and yellow flowers in spring. Many of the deciduous varieties also provide strong autumn colours. Berberis can be grown as specimen plants in mixed borders and also as low internal hedges or prickly boundary hedges.
2 Buddleja
Buddlejas are usually classed in this country as semi-evergreen which means that in mild winters they retain their grey-green leaves giving them an extra attraction. They are really grown, however, for their insect-attracting summer flowers in yellows, pinks, reds, blues, purples and white. Most have long panicles of flowers, others have rounded clusters. Many are large shrubs and need space but there are smaller varieties such as the ‘Nanho’ group and some recently introduced dwarf cultivars such as the ‘Buzz’ series. Particular favourites are Buddleja davidii ‘Black Knight’ with really dark purple flowers, B. davidii ‘Nanho Blue’ with its slender leaves and pale lilac-blue flowers and B. ‘Lochinch’ a vigorous shrub with fragrant, orange eyed, violet-blue flowers. Quite a contrast to these is B. globosa with its rounded clusters of fragrant, dark orange and yellow flowers in early summer.
Most Buddlejas flower on the current season’s growth and need cutting back hard in spring to within one or two buds above last year’s cuts.
3 Camellia
These are long-live evergreen shrubs with glossy leaves and spectacular spring flowers in pinks, white, cream and some yellows. They prefer neutral to acid soils and partial shade and do best of all when sheltered from cold, dry winds and early morning sun which can both damage the flowers. They fall into two main groups, the japonica and williamsii cultivars, the main difference being that once over the flowers will fall naturally from the williamsii but not the japonicas. Camellias form their flower buds for the next year during the late summer so it is important to keep them well watered during this time. Pruning is little more than dead-heading following flowering. Probably one of the most popular cultivars is Camellia williamsii ‘Donation’ with its soft pink, semi-double flowers but there are many other wonderful ones to choose from including C. williamsii ‘Anticipation’ which is what we have with its darker pink, peony-like flowers, the deep red C. ‘Black Lace’ and C. williamsii ‘Jury’s Yellow’ with its outer white petals and inner yellow ones.
4 Choisya (Mexican Orange Blossom)
Choisyas are evergreens with aromatic leaves, star-shaped, fragrant, white flowers in spring and again sometimes in autumn. The main species grown is Choisya ternata with its green leaves but an increasingly popular alternative is C. ternata ‘Sundance’ with its bright yellow leaves but possibly fewer flowers. Another attractive alternative is C. ‘Aztec Pearl’ with its narrower green leaves. They are fairly slow growing and light pruning following flowering just to maintain shape is usually all they require.
5 Cistus (Rock Rose, Sun Rose)
These are also evergreens grown for their showy, saucer-shaped, generally five-petalled, white, pink or purple flowers. They are Mediterranean plants so prefer sunny sites in well drained soils. They start flowering in June when they are a very welcome source of nectar for bees but they will continue to flower in spells through the summer. They are slow growing and therefore need little, if any, pruning. Particularly good varieties are Cistus x purpureus with dark pink flowers with maroon marks at the base of the petals and yellow centres, C. x corbariensis with its white flowers and yellow stamen and C. creticus with its purple-pink flowers and yellow stamen.
6 Erica (Heath) and Calluna (Heather, Ling)
Perhaps not obviously shrubs because they are low growing but their woody bases are noticeable particularly as they age. This can mean that they become rather bare at the base but this can be avoided or at least postponed by trimming them lightly after flowering each year. Both of these genera are evergreen shrubs, very good for ground cover and are full of flowers which are much loved by bees at certain times in the year. Most of their species and cultivars require an acid soil or ericaceous compost and flower in summer and autumn as in the wild on our moors and mountains. The flowers are small but numerous in colours ranging from white, through the whole range of pinks to purple. The foliage is also bright and attractive with all shades of green as well as yellows and even oranges and this makes them suitable for creating a patchwork quilt effect. One species, Erica arborea (Tree Heather), is much taller with some cultivars having striking golden foliage. There are also a couple of species of Erica which can tolerate some lime in the soil and which flower in the winter and spring so extending the flowering period. These include all the many cultivars of Erica carnea and E. x darleyensis. In the garden centres just look out for what are described as ‘winter flowering Heathers’. You might even see some Heathers for autumn and winter pots which have very brightly coloured flowers. These are actually white flowered Heathers which have been dyed to produce a more striking effect. They are one of the ‘Marmite’ plants, you either love them or hate them!, but don’t let them put you off Heathers as a whole which are very useful shrubs in any garden.
7 Hydrangea
For those of you that have been following my blogs this year the inclusion of Hydrangeas in my list of favourites won’t come as any surprise. They are grown mainly for their large, white, pink or blue, showy flower heads through summer and into autumn but many also have attractive flaky, peeling bark when mature and good autumn colour. Even when the flower colours have faded the flower heads are still attractive and most people leave them on the plants through the winter which also gives the new buds below some protection from the worst of the weather. They are removed in March/April time to allow the two strong buds just below them to develop. For most varieties of Hydrangea this light pruning is all that is required.
The best known Hydrangeas fall into two groups, Mopheads (Hortensias) and Lacecaps. The Mopheads have large, rounded flower heads and Lacecaps have flatter heads made up of small, fertile flowers in the centre surrounded by larger, sterile flowers. These are mainly Hydrangea macrophylla or H. serrata. Flower colour can be affected by the pH of the soil. Basically if you want a blue variety to stay blue then it needs to be grown in an acid soil (pH less than 7) or in ericaceous compost.
There is a third group which has become more popular recently as more cultivars have been introduced which is Hydrangea paniculata. These have conical flower heads usually in white which in many cultivars turn pink as they age. These flower on the current year’s wood so need to be pruned harder than the other types.
Two particular favourites are H. petiolaris, the climbing Hydrangea, which is very good for a shady fence or wall with its flat heads of white flowers and cinnamon coloured bark. This like all the others I have mentioned so far is deciduous but there is also an evergreen climbing Hydrangea, H. seemanii. Finally I have to give a plug for H. quercifolia (Oak-leaved Hydrangea) with its large, lobed leaves, conical panicles of white fertile and sterile flowers, the latter turning pink with age, and then all this followed by striking autumn colour. A real beauty!
Hydrangea quercifolia Hydrangea paniculata ‘Angels’ Blush’
8 Philadelphus (Mock Orange)
Surely no garden is complete without a Philadelphus in June! They are grown for their highly fragrant, 4-petalled cup or bowl-shaped, single, semi-double or double white flowers with cream stamens. Some such as P. ‘Sybille’ even have attractive purple marks near the centre of the petals.
- P. ‘Virginal’ is a widely grown vigorous, upright shrub with double flowers, ‘Belle Etoile’ is a smaller variety with single flowers and P. ‘Beauclerk’ also has single flowers but with pale purple markings at the base of each petal and yellow stamens.
9 Potentilla
These are perhaps not the most spectacular of the flowering shrubs but are really bright, free-flowering and cheerful shrubs which bring a splash of colour to any bed or border. The shrubby Potentillas (there are some herbaceous types) are mainly derived from P. fruiticosa and come in a variety of colours, white, yellow, orange and red, flower over a long period from late-spring to late-autumn, are trouble free, need little pruning, are very hardy and are generally no more than 3 feet (1 metre) high.
10 Rhododendron (which includes Azalea)
I know these are not everyone’s cup of tea- ‘what do they do once the flowers have gone?- but for a spectacular spring display in virtually the whole range of flower colours they are hard to beat and some would argue that they deserve a whole blog to themselves. They do, of course, require an acidic soil to keep them healthy and dark green but if that is not available in the garden it can always be provided by ericaceous compost in a container. They range in size from the Dwarf Rhododendrons such as R. ‘Blue Tit’(less than 3 feet, 1 metre) to the real giants such as R. falconeri (up to 40 feet, 12 metres) but don’t worry there are many in between!
Azaleas form a group within the genus of Rhododendron and whereas the true Rhododendrons are all evergreens Azaleas come in both deciduous and evergreen varieties. The evergreen ones tend to be smaller and are good for the front of beds and borders as well as for containers in colours ranging from white through pink to purple-blue. The deciduous ones are larger, brightly coloured and many are strongly scented such as R. luteum with its beautiful yellow flowers.
11 Spiraea
I’ve included these because there are so many different forms, heights, flower and foliage colours and they produce a great deal of flower often over long periods. Many flower in spring such as Spiraea ‘Arguta’ (Bridal Wreath) while others flower in summer such as S. japonica ‘Anthony Waterer’. The best for foliage colour also tend to be from the japonica group such as S. ‘Goldflame’ and S. ‘Golden Princess’.
With Spiraea even when the flowers are over One of the shrubby Potentillas
the new leaf growth shows colour
12 Viburnum
Last but certainly not least! This is such a good genus of more than 150 species and cultivars of evergreen, semi-evergreen and deciduous shrubs cultivated for their flowers, fruit and foliage including good autumn colour.
Flowers are often fragrant, white or creamy, pink-flushed or wholly pink in a tubular or trumpet form. Some species have flattened heads similar to Lacecap Hydrangeas. Fruits are usually spherical and may be red, blue or black.
The year begins with the winter-flowering deciduous Viburnums such as V. bodnantense and V. farreri (V. fragrans) which produce highly scented flowers on bare stems over a long period between winter and spring. V. tinus and its cultivars eg ‘Eve Price’ and ‘Gwenllian’ are evergreen and bear small white or pink flowers from late winter into spring followed by small, dark, blue-black fruits.
These are followed by the spring flowerers such as V. carlesii, V. x carlcephalum and V. juddii. These are all highly scented as is V. davidii which is also evergreen.
Next come the late-spring and summer flowering varieties such as V. plicatum which includes lovely cultivars such as ‘Lanarth’, ‘Mariesii’ and ‘Pink Beauty’ and all the forms of the well-known V. opulus (Guelder Rose). These include V. opulus itself which has white, lacecap-like flowers in early summer followed by bright red, fleshy fruits and then in autumn its three-lobed, maple-like leaves turn bright red. This species grows up to 16 feet (5m) but V. ‘Compactum’ is a slow growing, smaller form up to 5 feet(1.5m). V. opulus ‘Roseum’ or ‘Sterile’ (Snowball Tree) has spherical masses of flowers which start white and then develop a pink tinge. All its flowers are sterile so no berries are produced but the autumn colour is still good. Finally there is also V. opulus ‘Xanthocarpum’ which has all the attributes of the others but with the added attraction of bright yellow fruits!
Hopefully in the above you have found some shrub or shrubs which you would like to add to your garden although I have to admit that by the time I reached the end I had another 12 in mind! This is the beauty of gardening, there are so many lovely plants to choose from. Perhaps the best thing is to get along to the garden centre and see what catches your eye. As autumn is a great planting time there will be plenty on offer and hopefully you will be spoilt for choice. A few weeks ago we took out a large, old shrub which we had inherited from the previous owner and which was not bringing a great deal to the garden. As a result we have been able to fill the space created by moving a few plants from other parts of the garden, adding a few new ones and finishing off by planting some spring bulbs where we knew none existed already! The soil was beautifully moist and warm and the plants will be able to make good root growth before the winter and will get off to a great start next spring.
The next blog will be the garden in October which will concentrate on autumn colour and then in mid-October I will share with you some of my favourite trees for garden situations. Until then, keep safe and happy planting!
Keith