Climbing plants may be twining or self-clinging, or scandent, trailing or scrambling. They may be used for a variety of decorative and security purposes and may be deciduous or evergreen, flowering or grown for their foliage, annual or perennial. Climbers may also be used for ground cover, and then may need pegging down!
Wall shrubs are either slightly tender woody plants that benefit from the shelter of a wall or fence, or shrubs which have a lax habit and therefore benefit from support. Climbers and wall shrubs offer another dimension to both horticultural and aesthetic planting opportunities in the garden.
Self-clinging or twining plants
Plants capable of clinging do so by means of aerial roots e.g. Hedera helix, or by adhesive pads e.g. Parthenocissus quinquefolia that attach themselves to suitable surfaces such as walls, tree trunks or other solid surfaces and need only guidance and control of their overall size. Twining climbers twine stems, e.g. Lonicera spp., tendrils, e.g. Passiflora spp., or leaf petioles, e.g. Clematis spp. and grow through and over supports such as trellis, wires or other plants.
Scandent, scrambling and trailing plants
These plants attach themselves loosely to their support, if at all, and generally have lax stems which must be tied to a support in order for them to ‘climb’, e.g. Jasminum nudiflorum, or they can be used to trail over slopes or the sides of walls, e.g. Bougainvillea spp. (suitable for a protected environment) Rambling rose stems use thorns to scramble over supports or other stems. Stems can be tied to supports using a variety of materials such as twine, raffia, or plastic, foam, rubber or metal ties and rings.
Wall shrubs may be self-supporting but suitable for growing vertically, e.g. Pyracantha spp., or have a lax habit and benefit support such as Piptanthus nepalensis; others may be slightly tender plants, e.g. Garrya elliptica, therefore benefiting from the extra protection of a wall.
Choice of support
The support required for climbers will depend on a combination of factors: large or dense plants such as climbing roses or wisteria will need robust support such as heavy duty trellis or pergolas, large gauge wires or a large tree. For more delicate plants such as Clematis alpina lighter trellis, wires, plastic netting, metal or willow obelisks, pea sticks or shrubs are suitable.
The choice of plants should be matched to conditions: the ultimate size of a plant should not be underestimated, for instance Rosa ‘Wedding Day’ can grow to over 7m, whereas there are many much smaller climbing roses. Clematis montana may be suitable for growing through a large, robust tree, but would smother the more delicate Sorbus hupehensis, for example. Growing a vigorous climber in a confined space will lead to the need for regular pruning to keep it within bounds, possibly at the expense of flowers, so ultimate size should be matched to the space available.
Pruning requirements should also be considered when combining climbers, or growing climbers through shrubs. Ensure access is possible, particularly for vigorous plants such as wisteria that need regular pruning to produce good flower displays.
Planting a climber
Container grown specimens can be planted throughout the year when conditions are suitable, but spring and autumn are probably best. Excavate a planting hole 30cm from the base of any wall or hedge to avoid the driest and possibly impoverished soil. Clematis should be planted deeply, 5cm below soil level to stimulate basal bud development. This encourages good general growth and the production of new shoots should the aerial parts of the plant be affected by clematis wilt. Firm the backfill in layers, ensuring there are no air pockets. Remove any canes that supported the plant in the pot and spread the stems out, tying them in to the permanent support. Water and mulch the surface to conserve moisture.
Lastly, if you’re interested in expanding your skills or want to work in a career that covers environmental conservation or horticulture; landscaping, construction, green keeping and groundsmanship, why not pop along to one of our information events later this June. Our next one is Saturday 27th June between 10am – 2pm and you’ll be able to meet a range of staff to discuss options for this coming September.
Good luck and happy gardening!
For any gardening tips why not contact Tom Cole, Head of Faculty for Land & Environment, Writtle College, Chelmsford, CM1 3RR by post (including a SAE) or by email at firstname.lastname@example.org