Downpipe Greening

A wire rope parallel to the downpipe

The easiest way to green a drainpipe with climbing aids is to flank it with wire rope, as per cable system 1040. This emphasises the vertical lines. Often a lower lying rope (as with system 1020 or 1030) is sufficient; together with the downpipe and the clamps, it can create an attractive climbing field and stabilise the greenery (from wind, etc..). If there is enough space on both sides of the pipe, two ropes can be mounted, which is optimal. See below.

Suitable climbing plants

For such a greening, we recommend plants with 'soft shoots,' like these continuous bloomers: dipladenia/mandevilla, clematis viticella, clematis tangutica, rambler roses, and winter jasmine, which interweave quickly in front and behind the drainpipe and twine around the pipe upwards. Also suitable are: Dutchman's pipe, hops and leaf akebia vine, and if you want the foliage to be more lush and abundant, go with: trumpet vine, grapevine, and various 'wild vines.' Potted plants are also a great choice since the growth of the plant and its foliar mass will be limited by the trapped root system-- requiring less maintenance and care. If you do not plan to prune the plant every year, it is a good idea to have the wire rope end about 1m below the roof edge to prevent shoots from climbing over the gutter/roof or getting caught.

Several parallel cables

Installing two parallel cables -- one to the right and one to the left of the downpipe-- is particularly effective. Such an arrangement insures that even in strong winds, abundant vegetation can be held in place and will bear the majority of the load without the risk of the downspout fixtures being pulled from the wall. The often very light fittings of the drainpipe are not meant to absorb additional loads like greenery. Alternatively, two vertical ropes can be mounted on one side, closely beside the downpipe. Rope systems like 4010, 4020 and 7010 are best suited for this.

An alternative to cables: lattices/trellis grids

Lattices/grids are an alternative for creating lush greening around and on your downspout. A lattice can be mounted to the wall with four or six attachment points, thus relieving the downpipe clamps of the heavy plant weight. One must check in each individual case whether such lattices are an aesthetic advantage for the wall or whether the discreetness of wire ropes are more effective.

Direct greening on downpipes and possible structural damage

With annual plants and also with hops, downpipes can sometimes be greened directly, as the graceful climbing plants wind themselves around the pipe and find support at the clamps (or can be tied there). An accompanying wire rope as described above is always helpful, so that the shoots are better stabilised when the wind blows. It is also possible to put the shoots of climbing plants behind a drainpipe or twine them around it. Make certain that thick shoots do not push away the pipe, and that sensitive plaster on insulated house walls will not be scratched.

Climbing plants with a lot of leaf mass, however, can lead to the loosening of the generally light downpipe fittings when there are strong winds. In cases where the facade has direct contact with perennial plants, regular maintenance is needed to prevent structural damage. In particular, the condition of the pipe clamps must be checked periodically, since strong secondary shoots must be trimmed or removed before they pull the pipe from the wall. Drainpipe clamps are often not very sturdy, especially on insulated/stucco walls. We highly recommend the installation of support cables in these cases.

Light-weight trellises on the downpipe

The mounting of a light-weight trellis directly on the downpipe is possible, but is a special case, as structural damage is still possible here when the greening is full or vigorous. Such a greening is most promising in the base area with low-growing potted plants. Hardware-store standard downpipe (drainpipe) trellises-- made from aluminum wire or galvanised / plastic-coated steel wire-- are then suitable. They are available both in angled and curved forms for downpipes and are fastened directly to the pipe.