Shrubs Flashcards
BUXUS Sempervirens
quick facts
Common name Box
Box is tolerant of a wide range of soil types, provided there is adequate drainage and it does not dry out completely. A reliably moist soil is especially important if growing in full sun, otherwise the foliage may scorch. Box will tolerate deep shade and is ideal for planting beneath taller trees
If in full sun a reliable moist soil needed
Botanical name Buxus sempervirens
Up to 5m by 5m but can be kept smaller
Aspect Sun or shade
Hardiness Fully hardy
Difficulty Easy
Buxus Sempervirens
The following is a summary of the symptoms, pests and diseases you might encounter
Most serious is Box Blight
Leaves:
Excessive sunlight can cause discoloration and sun-scald to leaves
General bronzing or an orange coloration of the foliage is also due to environmental stress usually following hot, dry spells in summer, although a contributing factor may be root damage due to winter waterlogging
General yellowing of foliage may be symptomatic of waterlogging, especially on heavy clay soils
Over winter, leaf tips and margins commonly yellow due to low temperatures
Leaf discoloration will tend to be more common in exposed sites
Young growth in spring can also get caught by frost, turning them pale brown and often papery-looking
What is Box Blight and the control
Box blight is a fungal disease of box resulting in bare patches and die-back of box, especially in topiary and parterres.
Reduce the frequency of clipping to create more ventilation throughout the plants (regular pruning creates dense foliage and less air movement).
Avoid overhead watering as Cylindrocladium thrives in humid conditions.
As the disease is widespread, if possible, take cuttings from disease-free plants.
If the disease does break out, remove and destroy affected plants. If they are mature and highly valued, cut out all affected parts, clean up fallen leaves (including stripping and replacing surface topsoil to ensure complete removal) and treat with a fungicide. Spores can remain viable on fallen leaf litter for at least 6 years
Buxus sempervirens ‘Suffruticosa’
B. sempervirens ‘Suffruticosa’ – a much slower growing cultivar suitable for parterres and small hedges. Traditional dwarf box, compact and very slow growing
. Height and spread 90cm (3ft) by 1.5m (5ft
Buxus microphylla
B. microphylla – a naturally compact form of box that needs no clipping to form a shrub. Small, narrow leaves to 2cm (¾in) in length, turning bronze in winter. Prefers some shade. Suitable for colder areas. Height and spread 75cm (30in) by 1.5m (5ft
Buxus Sempervirens ‘Latifolia Maculata ‘
B. sempervirens ‘Latifolia Maculata’ AGM – a compact mound-shaped shrub with bright yellow young foliage, maturing to dark green marked yellow. Height and spread 2.4m (8ft) by 2m
Buxus Sempervirens ‘ Elegantissima ‘
B. sempervirens ‘Elegantissima’ AGM – a very dense, slow-growing, dome-shaped shrub with narrow, cream-margined leaves to 2cm (¾in) long. Height and spread 1.5m (5ft) by 1.5m (5ft)
Lavender in clay soil
On heavier soils, like clay and clay loam, lavender tends to be fairly short-lived, becoming woody at the base. To prolong the life of your lavender on heavier soil, add organic matter and gravel to improve the drainage and plant on a mound. If growing as a hedge, plant on a ridge to keep the base of the plants out of wet soil.
Ceanothus in general
Attractive blue, white or pink flowers make Ceanothus (or Californian lilac) a desirable shrub for a sunny, sheltered position.
Ceanothus problems
Do not plant in exposed situations and frost pockets as the plants can be affected by winds and frost injury. Prune back any frost damaged stems to healthy wood and remove dead stems in spring.
The root system can be damaged by excess moisture levels, leading to poor growth and dieback. Avoid planting in wet soils.
Ceanothus is lime tolerant, but plants can suffer from yellowing of the leaves between the veins (chlorosis) on shallow, chalky soils due to nutrient deficiency or cold soil conditions in spring.
It is also susceptible to honey fungus and scale insect attack.
4 Ceanothus cultivations and brief description
C. × delileanus ‘Gloire de Versailles’ AGM: A bushy deciduous shrub, bearing pale-blue flowers from midsummer to autumn. Height and spread 1.5m (5ft).
C. ‘Blue Mound’ AGM: A mound forming evergreen shrub, producing dark-blue flowers in late spring. Height 1.5m (5ft), spread 2m (6ft).
C. ‘Autumnal Blue’ AGM: An upright evergreen shrub bearing sky-blue flowers in late summer to autumn. Height and spread 3m (10ft).
C. thyrsiflorus ‘Skylark’ AGM: A bushy evergreen shrub producing dark-blue flowers in late spring to early summer. Height 2m (6ft), spread 1.5 (5ft).
Pyracantha general and quick facts
Pyracantha, or firethorn as it is also known, is a pretty shrub with attractive flowers and magnificent red, yellow or orange berries in autumn and winter. It is often trained against a wall or fence. It also makes an excellent evergreen hedge.
Quick facts
Common name Firethorn
Botanical name Pyracantha
Group Shrubs, hedges
Flowering time Spring to mid-summer
Planting time Anytime, but ideally autumn or winter
Height and spread 4m x 4m (12ft x 12ft)
Aspect Full sun or partial shade
Hardiness Most are fully hardy
Difficulty Easy
Pyracantha is suitable for any moderately fertile garden soil in sun or partial shade, including very dry free-draining soils and heavy clays as long as they are not prone to water-logging. Berrying can be reduced in shady sites, including against north-facing walls
Pyracantha problems
Pyracantha can suffer from the diseases pyracantha scab and fireblight. It can also be attacked by pyracantha leaf-mining moth and woolly aphid pests.
Lack of berries can be caused by:
Pruning too much: Wall-trained plants need an annual haircut with shears to be really neat. However this can slice off the flowers and hence berries. If berries are needed, don’t clip the entire plant - just shorten back the sideshoots in mid-summer as described above.
Poor pollination: This can occur in cold spring weather, particularly where plants are being grown in open situations exposed to strong winds, which can deter insects. It can also occur if plants flower during a wet period, when pollinating insects such as bees are not active.
Drought: This often occurs against a sunny wall in a dry border and can result in premature berry-drop even though pollination has been successful. Water thoroughly at 10-day intervals in dry conditions until the berries colour up in late summer.
Lack of feeding: Potassium (potash) encourages flowering and fruiting. Apply sulphate of potash at 30g per sq m (1oz per sq yd), tomato fertiliser, or comfrey pellets in early spring to an area extending at least 1m (3ft) beyond the branch spread.
Lack of vigour: Plants making only thin, weak, annual growth may remain without berries. Check that the growing conditions are suitable and the plant is not suffering from pest or disease affecting its vigour.
Frost: Late spring frosts can damage flowers, destroying the plant’s ability to produce fruit or berries. Flowers may appear undamaged until examined closely.
Hydrangea quick facts
Group Shrubs and climbers, some evergreen
Flowering time late spring to late autumn
Planting time Autumn and spring
Height and spread Shrubs: 80cm-7m by 90cm–2.5m (3–8ft); climbers: up to 15m (50ft) high
Aspect Sun or partial shade
Hardiness H5 (hardy, cold winter) to H4 (hardy, average winter)
Difficulty Easy to moderate
Hydrangeas thrive in a moist, but well-drained soil, in a cool, semi-shady part of the garden. Try to avoid exposed east-facing sites, where cold winds may damage young spring growth, and also avoid dry, sunny spots
Identify
Hydrangea arborescens ‘Annabelle’
‘Annabelle’ is a small, bushy deciduous shrub with broadly oval leaves and very large, spherical heads of white sterile flowers to 25cm across in summer
Identify
Hydrangea paniculata ‘Silver Dollar ‘
‘Silver Dollar’ has a compact habit, upright and moderately spreading, 125 x 165cm, with strong stems supporting the very dense, rounded, broadly conical panicles. Leaves yellow-green, stems greenish with white lenticels, pink flushed below, turning brown during and after flowering. Fertile florets are few, so the panicle is coloured by the crowded sterile florets, which are white becoming pink flushed. Slight fragrance. Suitable for small gardens
Identify
V. davidii is a small spreading evergreen shrub, with elliptic, deep green, leathery, three-veined leaves and flattened heads of small dull white flowers followed on cross-pollinated plants by long-lasting ‘metallic’ blue-black berries
1 to 1.5m
From China
Pest Disease free
full sun, partial, shade
V. x burkwoodii is a lax evergreen shrub to 2.5m tall, with glossy dark green, ovate leaves and highly fragrant white or pale pink flowers in mid and late spring
Identify
‘Roseum’ is a large, bushy deciduous shrub with 3- to 5-lobed leaves turning reddish in autumn. Creamy-white sterile flowers in dense rounded clusters to 6cm in width. No fruit
2.5.5m h and s
5 to 10 years
Identify
Viburnum opulus
“guelder rose”
V. opulus is an upright deciduous shrub to 5m, with maple-like, palmately lobed leaves which turn pink or red in autumn, and flat clusters of small white flowers surrounded by larger sterile flowers, and followed by translucent red berries
4 to 8 m Height 2.5 to 4m spread 10/20 years
sun or partial
‘Gwenllian’ is a bushy medium-sized evergreen shrub with neat, dark green, ovate leaves and compact clusters of starry white flowers opening in late winter from reddish buds, and followed by ovoid metallic-blue berries
full sun, partial , shade
1.5 to 2.5m H and S 10-20 years
Name this plant
Abelia X grandiflora
Description: A deservedly popular shrub with long lasting interest. This semi-evergreen shrub has arching stems clothed in dark green leaves and in later summer, soft pink and white flowers bloom over a long period. In addition showy soft pink bracts add interest through to late autumn. Abelia is fairly slow growing and so is ideal for small gardens.
Climate/Position: Thrives in full sun but also suited to partial shade. Protect from cold winter winds.
Height/Spread: Reaches 1.5 x 1.5 metres.
Soil Requirements: Suitable for any soil type. Prefers moist, well-drained site but is tolerant of drought.
Name this plant and details
Amelanchier lamarkii
Description: A large deciduous shrub or small tree which can be grown as a single stemmed or multi stemmed specimen. Excellent value as it has several seasons of interest. Masses of small white starry flowers open in Spring just before the young coppery leaves. Small black fruits ripen in amongst the green leaves in June (hence the common name) and leaves then turn rich shades of yellow, orange and red in autumn.
Uses: A really worthwhile small tree for any border or as a specimen in the smaller garden
Climate/Position: Sunny or partial shade.
Height/Spread: 6m x 4m bushy spreading habit.
Soil Requirements: Moist well drained soils lime free preferred.
Name and details
Arbutus unedo (unedo means one only …fruit)
Description: A handsome evergreen spreading shrub / tree with glossy, slightly toothed leaves. The shiney red-brown bark becomes rough and sheds with age. White bell shaped flowers, sometimes tinged pink are produced late in the year from September to November. Red strawberry-like fruits are also produced in the autumn at the same time as the flowers and so together they create a wonderful show amongst the dark green leaves at this time of year.
Climate / Position: Full sun in a sheltered site. Fully hardy.
Height / Spread: Height 8m and spread 8m. Though rarely reaches this height.
Soil Requirements: Grow in a fertile, well drained soil. Will tolerate alkaline soil.
Pruning: No pruning required. Remove wayward shoots in late winter to early spring.
easy to grow
Name and facts
Description: A. japonica ‘Variegata’ is a large bushy, rounded evergreen shrub with big handsome glossy, toothed leaves covered in yellow blotches. A female variety of laurel with small insignificant purple flowers in spring which may be followed by clusters of red berries in autumn (see below for details). Spotted laurels give colour and structure throughout the year and are ideal for a formal hedge. They are tolerant of adverse conditions including pollution and so particularly suited to urban and suburban gardens.
Climate / Position: Very versatile, noted for shade tolerance but will also grow in partial shade or even full sun.
Height / Spread: Larger form of Aucuba reaching 3 x 3 metres.
Soil Requirements: Thrives in most soils, including dry ground near hedges and trees. Avoid waterlogged soils.
Pruning : Shrubs may be left to grow unchecked, or lightly trimmed to shape once annually in late summer, best to use secateurs to avoid cutting the large leaves. Can also be grown and pruned as an evergreen hedge.
Name this
Box blight
