Climbers for terrace pergolas
– auf Deutsch lesen – During the heat of the summer months, not everybody has the luxury of a cool, shady tree canopy to withdraw under. Many people have to make do with an umbrella, sail or awning. These provide shade, but unlike foliage, make little difference to the temperature. Having a pergola to cover the terrace can make a huge difference.
In the early spring, when each ray of sunshine is appreciated, the framework of a freshly pruned climber allows plenty of light through. By mid-summer it will have developed into a thick canopy that not only cuts out the sun, but also creates a much cooler micro-climate.
Which climbers are suitable to shade a terrace?
It is important to find a vigorous climber that can cover a larger enough area. Ideally one that can be pruned hard in late winter/early spring but that will provide a closed canopy by July.
A Wisteria can easily manage, but has its main flowering season early on, before you are likely to sit outside. Fortunately, many varieties are able to continue to produce the odd bloom in the course of the summer. Wisteria ‘Prolific’ is one of these (see image above).
Don’t forget they require pruning twice a year: in summer to reduce the new growth to about 6 buds, in early spring to prune it further back to 2-3- buds.
Nothing more idyllic than an early summer’s lunch under a flowering rose canopy. Finding the one with the right degree of vigour is important. Quite a few climbing roses are perfect for an arbour, but will struggle to cover a larger stretch of pergola, providing no more than partial shade. The more vigourous ramblers will manage this without a problem, but their strong new shoots that appear during summer may well turn into a prickly hindrance. Charming but once-only flowering is Rosa ‘Felicité et Perpetue’, or a favourite repeat-flowering, not too invasive rambler is ‘Guirlande d’Amour’. Both of these tend to produce numerous shoots, making them quite bushy at the base, but provide many stems to lay across wires that can create a closed canopy.
Clematis and Lonicera – less suited climbers
Both of these are less suited. Though the Lonicera will produce its deliciously scented blooms during the summer months, they cannot be pruned hard in spring, to lighten the canopy. With time they will form an untidy mat of vegetation. The summer-flowering clematis which do cope with spring pruning, do not have the required vigour. A spring-flowering Clematis montana does, but these too cannot be pruned in spring, and will take valuable light during the dark season. Both plants are naturally associated with woodlands, and prefer to have their feet in a cool, shady spot.
This very exotic-looking climber with its colourful large trumpets first caught my attention in Italy. In England it is often considered as not suited to the climate, but this has more to do with lack of heat and sunshine. These climbers really benefit from a warm, sunny climate in order to produce abundant flowers in summer. Colours range from a warm yellow (Campsis radicans ‘Flava’), to soft orange-red (C. grandiflora) and deep red of C. tagliabuane ‘Summer Fire Jazz’.
Vitis – interesting climbers
Wine is an interesting genus for a pergola. A desert-grape such as Vitis vinifera ‘Black Hamburg’ or the highly perfumed ‘Fragola’ will give the added advantage of providing an edible crop, but there is also the down-side that the fruits that are not eaten (by yourself or by the birds) need to be removed on time, as they could stain a terrace and may also attract unwated wasps. Even the purely decorative species such as the large-leaved Vitis coignetii with its splendid autumn colour, or the red-leaved Vitis vinifera ‘Purpurea’ produce fruits, though the sour grapes of the latter tend to be ignored by birds.
Although these can be a bit of a thug as most of them are very vigourous climbers that will invade the entire house if not kept in check, they have the advantage of climbing unaided. They also loose their foliage early, so that as soon as the darker autumn-days come, natural daylight is allowed to enter again. The added bonus of course if the splendid, if early autumn colour. Invariably, they are the first to turn a luminous red as soon as the air turns autumnal.
The choice is yours! Don’t forget that autumn is also the best planting time for climbers – at long last we are getting some very welcome rain, that finally brings much needed moisture into the soils.