“…a garden office escape now that all the family is working from home.”
A dry river bed design helps divert heavy rain, says Louisa Gilhooly
Louisa Gilhooly creates a dry riverbed design,
Q How can I prepare my garden for weather extremes?
WE’RE ALL AWARE how climate change is affecting our weather, bringing more extreme events such as flash flooding and periods of drought. Our gardens need to evolve in order to cope with these extremes, conserve precious water and stay looking great all year round.
There are lots of ways we can adapt to climate change, chiefly through our choice of plants and garden design. One idea is to create a dry river bed feature – usually found in areas that, for the best part of the year, are arid but in the rainy season become flooded for a short period of time. Features including swales, ditches, berms and gullies are often used by urban landscape designers to help manage temporary flooding near roads, but they can assist drainage in gardens too.
To create your own dry river bed design, study the natural lay of the land. In particular, watch how water flows during heavy rainfall, and site your ‘riverbed’ at the lowest point of the garden: this is where the water naturally drains to – perhaps resulting in a large puddle or soggy, mossy lawn. By turning the area into a dry river bed you can channel the excess rainwater to a point where it naturally soaks into the ground, or create a rainwater collection pond.
Lay a hosepipe across the low area to create gentle, serpentine curves. Dig deeply enough and any storm runoff will collect in the gully. Pile the soil up around the gully as you excavate, creating the berms (sides). Finish by laying a sheet of landscape fabric over the entire surface of the gully, including the angled sides, to prevent weeds from popping through.
Line your riverbed with gravel and stones, choosing rounded stones and pebbles in a colour that harmonises with the house. Add in a few larger boulders as points of interest. As a general rule, use the smallest stones on the bottom of the gully and save the largest for providing interest at the top. ➤
Site your ‘riverbed’ at the lowest point... where water naturally drains to
1 Miscanthus sinensis
‘Ferner Osten’ Deciduous green, arching, clump-forming grass turns reddish pink in autumn, with flower plumes Aug-Sept. Best in sun and fertile soil. H1.5 (5ft) S1m (3ft 3in)
2 Rodgersia ‘Bronze Peacock’
Clump-forming perennial with dramatic bronze leaves and pink flowers May-July. Prefers part shade and moist but well-drained soil. H55cm (22in) S70cm (28in) 3 Viburnum plicatum tomentosum ‘Kilimanjaro Sunrise’ Deciduous shrub with white-flushed pink lacecap-like flowers on tiered branches, MayJune. Sun or part shade. H3m (10ft) S1.5m (5ft)
4 Heuchera ‘Caramel’ Semi-evergreen perennial with scalloped pinkish-coral foliage with darker undersides. Creamy pink flowers emerge June-Aug. Grows in sun or part shade. H and S50cm (20in)
5 Euphorbia polychroma
‘Purpurea’’ Attractive red-leaved euphorbia with acidbright flowers April-May. Plant in sun or part shade and a moist but well-drained soil. H40cm (16in) S60cm (2ft)
6 Hakonechloa macra
‘Sunflare’ Deciduous grass with golden leaf blades and contrasting tips that colour red in autumn. Sun or part shade and a moist, cool spot. H and S45cm (18in)
7
Polygonatum hybridum Evergreen perennial Solomon’s seal has graceful, arching stems bearing dangly white flowers May-June. Cool shade and moist soil. H1.5m (5ft) S30cm (12in)
8
Hosta ‘Sum and Substance’ Architectural perennial with large, ribbed leaves and pale lilac flowers July-Aug. Best in shade and fertile, moist but well-drained soil. H75cm (30in) S1.2m (4ft)
9 Athyrium niponicum
pictum ‘Silver Falls’ Deciduous fern that forms clumps by rhizomes, with silvery-green fronds that feature maroon midribs. Full or part shade and moist, fertile soil. H50cm (20in) S1.5m (5ft)
10 Podophyllum versipelle
‘Spotty Dotty’ Unusual perennial with red flowers that hang beneath the foliage Jun-Jul. Best in shade and rich, fertile, moist soil. H and S40cm (16in)
11 Asarum europaeum
Semi-evergreen rounded glossy leaves form a mat of perennial ground cover. Easy to care for in part shade and humusrich, moist soil. H15cm (6in) S30cm (12in)
12 Pachysandra terminalis
Evergreen groundcover plant forms dense mats of shapely glossy foliage in sun or shade. Small white flower clusters May-June. H20cm (8in) S1m (3ft 3in)
13 Ophiopogon planiscapus
‘Kokuryu’ Clumpforming black lilyturf with black grassy leafblades. Small purple flowers June-Aug. Sun or part shade. H20cm (8in) S30cm (12in)
14 Acer palmatum ‘Red Pygmy’
Deciduous Japanese maple forms a mounded tree with reddish-purple leaves. Needs sheltered, shady spot with moist but well-drained soil. H and S1.5m (5ft)
15 Thuja occidentalis ‘Danica’
Dwarf white cedar makes a rounded emerald green dome; turns bronze in a cold winter. Sun or part shade and a deep moist well-drained soil. H and S50cm (20in)