Ascending shrubs and vines (climber plants) are prominent elements of the woody plant flora in Hong Kong. Climbers are also very popular garden plants. Being woody, they last longer than herbaceous plants and provide a year-round display apart from their flowering season. Climber cultivation is generally easy since most climbers are evergreen and hardy. Climber plants originate from many climatic zones with different growing conditions. They are suitable for a wide range of climatic regions and garden landscapes.

Climbers from non-tropical areas need winter chilling to promote flower bud initiation. Whereas those from tropical areas require less winter chilling or cannot be planted outdoors in Hong Kong. Climbers are classified into woody vines (climbers with elongated, trailing stems) and woody shrubs (climbers with shorter, upright growing stems). Climbing bamboos do not form a distinct category in the plant classification system. Climbers can be used to cover walls or fences, as well as to create privacy barriers. Climbers are also used as summer screens in gardens, or to cover unsightly walls, buildings, and hedges.

The Climbers of Hong Kong Climber plants in Hong Kong belong to 105 species belonging to 42 genera and 20 families. The major families are Vitaceae (vinaceous ornamentals), Bignoniaceae (bignonia, trumpet-shaped flowers), Sterculiaceae (turban-shaped flower), and Caprifoliaceae (honeysuckle family). Climbers are most diverse in the south of Hong Kong, where they comprise about 20% of woody plant species. Climber numbers decrease dramatically towards the north of Hong Kong, especially in the colder climate of the New Territories. Climbers are rarely found in northern Hong Kong except on top of high mountains or on flat-topped karsts within lowland forests. Climber plants can be divided into three climatic groups: winter-sensitive, summer-sensitive, and evergreen climbers.

Climbing species

Tropical regions (e.g. Japan, Taiwan) and warm temperate regions (e.g. Australia) are winter-sensitive and grow well outdoors in Hong Kong when grown with suitable summer sheltering or protection from sea winds. Climbing species from cool temperate and cold climate regions (e.g. China, Korea) require winter protection with shelter from cold winds. Climbers form only a minor portion of woody species in subtropical regions such as the Himalayan foothills. But they are an important element of forest understories and can grow well on tropical mountains at moderate elevations (e.g. Mt. Emei in Sichuan, China). Climbers from alpine regions are usually evergreen, e.g. Ci Gong Ju Hua (Viburnum grandiflorum) in the Himalaya region, and Climber species also occur on high mountains of tropical areas such as New Guinea and Malaysia.

Thermal Requirements

Climbing plants have different thermal requirements according to their origin. Climbers from warm temperate and cool temperate regions (e.g. Ouyang 6, Climbing Bamboo; Viburnum spp.) can survive temperatures as low as -5 °C to -10 °C without any significant damage. Although freezing or mild frost may kill the terminal growth of these climbers. Climbers from tropical and subtropical regions cannot tolerate freezing temperatures. Whereas those from alpine areas (e.g. Climbing Hydrangea) can survive freezing temperatures without any damage.

Climbers require a certain minimum temperature for the initiation of flower buds. And also need cold winter temperatures to promote flowering in the spring season. Climber plants with long flowering periods need a period of warm temperatures and summer sunshine to form flower buds. Climbers that do not flower until the second or third year after planting, such as Climbing Hydrangea, Climbing Bamboo, and Climbing Viburnum, should be protected from strong sea winds in their first growing season when they are most vulnerable to damage by strong winds.

Less used climber plants : Climbing bamboos

Climbing Bamboo are particularly sensitive to frost damage. It should be sited in a sheltered position, preferably with some overhead shelter from buildings or trees from which their branches might break in a strong wind. Climbers require approximately 50-200 cm of sunlight for good growth. Climber plants from tropical and warm temperate regions (e.g. Climbing Bamboo, Climbing Hydrangea) require more sunlight but prefer protection from strong summer sea winds with some overhead shelter such as trees or buildings.

Climbers that originate from cool temperate and cold climates (e.g. Climbing Viburnum) need less sunlight but are also tolerant of sea winds and can tolerate some shade or partial shade. Climbers that originate from alpine regions are usually evergreen and require very little sunlight (e.g. Climbing Azalea). Climbers grown in open garden conditions will need to be pruned regularly to keep them within bounds. With long flower stems such as Climbing Hydrangea and Climbing Bamboo require more pruning. And with short flower stems, such as Climbing Azalea, Climbing Viburnum, and Climbing Japonica, may need little pruning to achieve the desired effect.

Classification of Climber Plants:

Climbers can be classified into two types based on period of growth: early-flowering climbers and long-flowering climbers. Climbers from warm temperate and tropical areas can flower within 1-2 years after planting (e.g. Climbing Bamboo), whereas those from cool temperate and cold climates require 3 to 5 years or longer before flowering (e.g. Climbing Hydrangea). Climbers that flower before the second year after planting usually have weak wood. They are not suitable for exposed sites on buildings unless protected against strong winds.

Climbers from tropical areas generally need subsequent pruning each winter. Whereas those from cooler temperate regions can retain some old stems for several years in succession before needing hard pruning each winter. With strong stems that are not required for subsequent flower display should be removed as they will become a visual obstruction in the garden. Climbers with weak stems that will not support large flowers or multiple inflorescences also require removal.

Uses of Climbers:

Climbers can provide interest to gardens at any time of year, but tend to be more effective when flowering occurs in the early summer months or when evergreen foliage provides a background to deciduous shrubs and trees during winter. Climbers also provide convenient access to elevated areas of buildings. It can be used to mask air conditioning units that are not aesthetically pleasing. Climbing plants generally produce masses of flowers. But flowering may be sparse on plants grown in pots or containers that do not provide sufficient growing space. Climber plants grown in containers that are moved inside during the colder winter months require protection from frosts to avoid damage to their growth and flowering potential. Climbing plants may be permanently installed by attaching them with suitable mesh or netting material around existing brick, stone, timber, or concrete walls.

Conclusion:

Climbers are a type of plant that grows upwards, and they’re very popular for gardens. They can be either vine-like or shrubby in form, so there’s something to suit every garden style. The best part about climbing plants is that they last longer than other types of flowers because the woody stems cling tightly to their supports. If you want an easy way to add color and life to your garden, try planting some climbers!