Rain Gardens

With the extensive loss of front gardens, and other planted areas, including lawns, urban flooding occurs. This is because rain falls in towns and cities faster than it can be drained by the sewer network, absorbed into the soil or conveyed to streams, rivers, water bodies or reservoirs.

In recent years, with climate change, this is a major re-occurring problem in towns and cities throughout the UK.

Rain gardens are a key component of eco-friendly and sustainable landscapes.

Benefits of rain gardens, as recognised by the RHS

Low maintenance garden – no watering once plants have established
Can absorb up to 30% more water than a lawn
Offers opportunities to plant a wide range of perennials
Reduces erosion by slowing heavy rainfall
Increased planting attracts insects and birds
Avoids the need to sink a soakaway

Sustainable Drainage Systems (SuDS)

Rain gardens provide an inexpensive and instant way to create an attractive attenuating Sustainable Drainage System (SuDS)* that will:

slow surface water flows
significantly reduce surface water flood risk, particularly in urban areas with extensive sloping roof areas
filter pollution and improve water quality

*SuDS - Sustainable drainage systems include a range of techniques for holistically managing water run-off to reduce the quantity, of surface water that drains into sewers from a development. The SuDS increase the quality of the water release by a natural filtering purification processes. In general SuDS mimic natural systems, and manage rain close to where it falls. SuDS not only reduce the burden on our sewerage system, they can also help wildlife to thrive in urban areas, with many of the drainage systems being intrinsically wildlife friendly.

Rain Garden Planters

Rain Garden Planters, or Gutter Planters, adopt the principles of SuDS,

Designed to:

manage rainwater run-off from domestic and commercial roofs
reduce the risk of flooding in the sewer network
improve the quality of surface water entering streams and rivers

Rain garden planters make use of the water that lands on the roof and works in the following way:

1. Water from the downpipe is directed into the planter.

2. The soil / compost mix absorbs and stores the rainwater for the plants to use.

3. Excess rainwater filters into the gravel layer and drains out the base drainage pipe, as illustrated in the adjacent diagram.

Find Out More

Best Plants for Rain Gardens

Plants for rain planters have to be able to tolerate some wetness at the root zone as well as grow in more normal conditions.

Typical plants include Iris pseudocorus and a range of perennials such as:

Geraniums
Persicarias
Hemerocallis
Grasses such as Deschampsia or Miscanthus

Some shrubs such as Cornus sanguinea or even trees, such as Betula would be suitable for a large planter.

See the table below for a comprehensive list of plants suitable for rain gardens, as recommended by South East Rivers Trust:

Common name	Scientific name	Habit	Sunlight and Aspect	Origin
Guelder rose	Viburnum opulus	Perennial shrub	Any	Native. Flowers attract insects and berries are eaten by birds.
Dogwood	Cornus sanguinea	Perennial shrub	Any	Native. Leaves are larval food for vase bearer moth and berries eaten by birds. Often planted for attractive winter stems.
Culvers root	Veronicastrum virginicum	Herbaceous perennial	Full sun or partial shade	Non-native. Tall with long terminal blue flower spikes. On the RHS ‘plants for pollinators’ list.
Aster	Aster spp.	Herbaceous perennial	Full sun or partial shade	Non-native. Often late flowering. Clump forming. Several species on the RHS ‘plants for pollinators’ list.
Black eyed susan	Rudbeckia birta	Herbaceous annual or biennial	Full sun or partial shade	Non-native. Spectacular yellow and black flowers. On RHS ‘plants for pollinators’ list.
Stinking hellebore	Helleborus foetidus	Herbaceous perennial	Full sun or partial shade	Native. Winter flowers.
Montbretia	Crocosmia spp.	Deciduous rhizomatous perennial	Partial shade	Naturalised. Red flowers. Thrives in most conditions.
Bugle	Ajuga reptans	Rhizomatous perennial	Partial shade	Native. Low growing and will form a mat.
Columbine	Aquilegia spp.	Herbaceous perennial	Full sun or partial shade	Non-native. Clump forming with tall flower spikes. On RHS ‘plants for pollinators’ list.
Inula	Inula hookeri	Herbaceous perennial	Partial shade	Tall clump forming with yellow flowers. On RHS ‘plants for pol- linators’ list.
Hemp agrimony	Eupatorium cannabinum	Herbaceous perennial	Full sun or partial shade	Native. Sub-shrubs with pink flowers.
Bellflower	Campanula glomerata	Herbaceous perennial	Full sun or partial shade	Native. Clumps bearing violet-blue bell shaped flowers.
Sneezeweed	Helenium sp.	Herbaceous perennial	Full sun	Non-native. Clump forming with red flowers. On RHS ‘plants for pollinators’ list.
Lesser periwinkle	Vinca minor	Perennial sub-shrub	Any	Non-native. Ground cover with blue flowers.
Elephants ear	Bergenia sp.	Rhizomatous perennial	Full sun or partial shade	Non-native. Large leaves and pink flowers.
Plantain lilies	Hosta spp.	Herbaceous perennial	Part shade	Non-native. Attractive light coloured flowers.
Yellow flag	Iris pseudocorus	Rhizomatous perennial	Full sun or partial shade	Native. Likely to prefer wetter areas near inlet.
Siberian flag	Iris sibirica	Rhizomatous perennial	Full sun or partial shade	Non-native. Blue flowers. Prefers moist but well drained soil.
Garlic and onions	Allium spp.	Bulbous perennials	Full sun	Non-native. On RHS ‘plants for pollinators’ list.
Soft rush	Juncus effusus	Evergreen perennial	Full sun or partial shade	Native. Form tussocks – likely to prefer wetter areas.
Pendulous sedge	Carex pendula	Rhizomatous perennial	Full sun or partial shade	Native. Nodding flower spikes. Likely to prefer wetter areas near inlet.
Zebra grass	Miscanthis sinensis	Perennial, deciduous grass	Full sun	Non-native. Tussock forming ornamental grass with silky flowers.
Switch grass	Panicum virgatum	Deciduous perennial grass	Full sun	Non-native. Tussock forming ornamental grass.
Royal fern	Osmunda regalis	Deciduous fern	Any	Native. Large clump-forming plants.
Male fern	Dryopteris felix-mas	Deciduous or evergreen fern	Partial shade or full shade	Native. Large shuttlecock-like form.
Broad buckler fern	Dryopteris dilatata	Deciduous or evergreen fern	Partial shade or full shade	Native. Large shuttlecock-like form.

(From Thames Water UK Rain Garden-Guide)

Rain Garden Planters: An Attractive Adaptation of Sustainable Drainage Systems (SuDS)

Rain Garden Planters are designed to help prevent Flooding

Even if you don’t have room for a rain garden you can still implement sustainable stormwater management. Rain garden planters, or gutter planters, handle rainwater runoff from rooftops and operate like a rain garden inside a planter.

Rain garden planters are perfectly suited to small spaces, as they can be built close to buildings in any configuration and don’t take up very much space.

These planters are an attractive adaptation of Sustainable Drainage Systems (SuDS) which slows surface water flows,
and reduces surface water flood risk.

With both bioretention and additional internal storage, these planters are an innovative solution to property level retro-fit SuDS, and can work out very much less expensive than most groundworks interventions.

The planter can be made from a number of materials, but we prefer commercial quality Larch Planters for the following reasons:

produced by UK craftsmen using Larch from sustainably grown larch woodlands.
Larch produces its own intrinsic preservative providing a very long planter life without the use of toxic preservatives.
Alternative materials are linked to non sustainable production issues from energy consumption to pollution or toxic issues.

A rain garden planter is a waterproof container, with an internal large water storage area linked to a controlled release internal drainage system.
Above the important water storage area is a series of filter membranes separating the plants and compost/soil mix at the top of the planter for aesthetic and Biodiversity value

These membrane and soil / planter layers filter the water before it passes to the next stage of rainwater management.

Water may discharge from a planter into the normal drains or it could be diverted further into a Rain Garden.

For an enhanced biophilic and aesthetic effect, we like to encourage the construction of landscaped features that the water could travel along and slowly percolate into the soil, such as an attractively constructed rill, gulley or channel into a garden bed, as in the example below.

For Further details of our SuDS Planters click HERE