Some plants can get a bad name without really deserving it. They are either too successful and seed around (buddleia, commonly referred to as "the railway plant") or are seen as dated (dwarf conifers and pampas grass certainly fit into this category).
Slipping into the "dated" category is the genus Cytisus, part of the broom group. This is a shame because they provide a stunning display of pea-like flowers, with many providing a fine fragrance.
The brooms are all plants in the legume family Fabacaee and then within the tribe Genistae, which includes the genera Cytisus, Genista and the relatively newly named Argyrocytisus. The reason for the common name is the upright, green, almost leafless shoots of many of ?this group.
The genus Cytisus is made up of about 50 species, with plants growing on scrub and heathland in Europe, western Asia and North Africa. They are deciduous or evergreen shrubs, producing masses of brightly coloured — usually yellow — pea-like flowers, which are often highly fragrant, in late spring or early summer. A few species flower in autumn. They are highly attractive to insects, proving an excellent source of nectar and pollen. Not all the species have stems clothed in minute simple leaves. There are some that have leaflets, trifoliate in form. They range in size from low-growing, prostrate shrubs to small trees.
Probably the best-known are the medium to tall shrubs C. scoparius, ?C. multiflorus and the hybrid C. × praecox, from which many varieties have been produced — providing a range of flower colours from creamy whites to mahogany reds.
A highly popular shrub is Argyrocytisus battandieri (formerly known as Cytisus battandieri), which has fantastic grey leaves that have a silky sheen and produces cone-shaped flower heads of pineapple-scented yellow flowers.
There is also the related genera Chamaecytisus, which includes Chamaecytisus purpureus, a pretty shrub that produces lilac-purple flowers in May.
They are said to tolerate a wide range of soils apart from shallow, chalky ones and extremely acid conditions. They all prefer a position in full sun and are generally hardy down to -15°C. The nicely scented Tenerife broom, C. supranubius, is a little more tender, but given good drainage and a sheltered location it will tolerate occasional lows of -10°C. They resent root disturbance so plant directly from the pot into their carefully chosen final position.
Cytisus often become leggy as they age so pruning is best done regularly, after flowering. The vigorous species and hybrids such as C. scoparius, which flowers on the previous season’s wood, should be cut back by up to two-thirds of its length. Do not cut into old wood though because new growth seldom breaks from it. Pruning the prostrate forms can spoil their look so it is probably best to just remove their developing seedpods instead.?
What the specialists say
Peter Chapman, managing director, Perryhill Nurseries, East Sussex
"Cytisus are excellent as fillers, giving a bright burst of colour, though not as popular as they were in the past. They are inclined to be short-lived but given a neutral or acid soil in a sunny position they generally thrive.
"Agrocytisus battandieri, which ?was formerly known as Cytisus, is fabulous for a warm wall, with large upright flower heads smelling of pineapple. In my experience Cytisus [Chamaecytisus] purpureus and its forms can be a bit tricky in pots but are very pretty when in full flower.
"Cytisus ‘Minstead’ is a variety that stands out for me, producing a mass of small, white, lilac-flushed flowers in May and June that are glorious, delicate and airy, and the Agrocytisus with the smell of pineapple.
"Just remember that they can be short-lived and care has to be taken if they are pruned, as they resent cutting into old wood. Cytisus scoparius seeds freely and where it has been introduced abroad is often considered an invasive weed."
Ian Garland, owner, ?Grangehill Landscapes, London
"I know some people no longer plant the brooms as maybe they are seen as a bit 70s, but I still love those pea flowers and they come in so many colours. Some of my favourites are the rich pink C. ‘Burkwoodii’, the gorgeous burnt orange effect of ?C. ‘Lena’ and the dark red C. × boskoopii ‘Boskoop Ruby’.
"They are easy to care for in the garden, just needing to be trimmed generally after flowering to prevent legginess. You might have to watch out for gall mite too. The smaller prostrate shrubs are good for a rock garden, spilling over the rocks. They don’t need much pruning.
"Not a Cytisus any longer but I ?love the pineapple broom, Argyrocytisus battandieri. It is a tall shrub and has lovely, downy, ?silvery-grey leaves, and if grown in ?a sheltered location, such as against a wall, it produces a fantastic pineapple scent and bright-yellow flower heads. Stunning."
Species and varieties
Argyrocytisus battandieri, the Moroccan broom, is a medium-sized deciduous shrub with trifoliate silvery-grey leaves that are very silky when young. It produces large clusters of attractive yellow that are scented of pineapple. Height and spread: 4m.
Cytisus ‘Burkwoodii’ Award of Garden Merit (AGM) (H5) is a small shrub with erect shoots bearing cerise flowers with deep-crimson wings and yellow edges. Height and spread: 1.5m.
C. ‘Lena’ AGM (H5) is a vigorous, compact, free-flowering broom with deep-red standards, red wings with yellow margins, and pale-yellow keels. Height: 1.2m. Spread: 1.5m.
C. nigricans ‘Cyni’ AGM (H5) is a compact, upright, deciduous shrub with leaves of three leaflets, dark-green above and pale-green beneath. Long slender terminal spikes of scented yellow flowers appear in summer, later than is typical for this genus. Height: 1m.
C. scoparius, the common broom is a familiar medium-sized native shrub. It has an erect habit with slender green shoots bearing small ternate leaves and rich butter-yellow flowers in late spring. Height: 2-3m.
C. × beanii AGM (H5) is a ?semi-prostrate shrub with simple linear green leaves and rich yellow flowers along the green branches ?in late spring or early summer. Height: 35cm.
C. × boskoopii ‘Boskoop Ruby’ AGM (H5) is a small deciduous shrub of rounded habit with abundant deep-crimson flowers on upright shoots in late spring and early summer. One of the most striking red hybrids. Height and spread: 1.2m.
C. × boskoopii ‘Hollandia’ AGM (H5) is a small deciduous shrub with slender green shoots, small leaves and pale-cream flowers. Height and spread: 1.5m.
C. × boskoopii ‘Windlesham Ruby’ is a rounded bushy shrub with tiny leaves and slender upright shoots that remain green in winter. Rich pinky-red flowers smother the shoots in late spring and early summer. Height: 1.5m.
C. × boskoopii ‘Zeelandia’ AGM (H5) is a small bushy shrub with broom-like green stems and small dark-green leaves. It produces an abundance of pink and cream flowers in late spring and early summer. Height and spread: 1.5m.
C. × kewensis AGM (H5) is a small prostrate shrub with arching branches, covered in cream flowers in late spring. Height: 45cm.
C. × praecox ‘Albus’ is a compact shrub with small leaves and arching shoots that remain green all winter. Produces abundant small white flowers in mid-to-late spring.
C. × praecox ‘Allgold’ AGM (H5) is an outstanding small shrub with arching sprays of long-lasting yellow flowers. Height and spread: 1.5m.
Thank you to Floramedia, which supplied the images for this article from its photo library www.floramedia-picture-library.com