A rain garden or stormwater garden is designed with the purpose of temporarily holding rain water collected from runoffs that come from building roofs, driveways and patios.

It is a shallow depression formed in a part of the garden that naturally slopes. It is planted around the perimeter with a natural planting scheme using shrubs and perennials.

Rain gardens effectively remove up to 90% of pollutants and chemicals as well as up to 80% of sediments from the rainwater runoff.

In comparison to a conventional grass lawn, rain gardens will soak up to 30% more water.

A rain garden only holds and soaks away water in extreme, heavy rain conditions; it is not a water garden or a pond. In actual fact a rain garden is mostly dry.

It typically holds water only during and following rainfall.

As rain gardens will drain within 12-48 hours, they prevent the breeding of harmful bugs and pests

Rain water runs off impermeable surfaces, such as roofs or driveways. In doing so it collects pollutants such as dirt, fertiliser, chemicals and bacteria along the way.

The polluted water then enters storm drains flowing directly to nearby streams and ponds.

By making a rain garden we can collect rainwater runoff which allows the water to be filtered and purified by vegetation. In turn the water percolates into the soil taking a lot less pollutants with it.

In the design of a rain garden, typically six to twelve inches of soil is removed, compost and sand is then added to increase water infiltration.

It is advisable to do a soil test as this will indicate the type of soil you have and the amount of sand and compost that is required.

Rain gardens should be constructed on the downside slope from your property and collect rainwater runoff from the lawns, roof, patios and driveway. Once water collects in the rain garden, infiltration may take up to 48 hours after heavy rainfall. As rain gardens incorporate native vegetation no fertilizer is needed and maintenance is minimal.

Runoff rain water can be collected by using water butts, this water is then redirected to your rain garden.How to Make a Rain Garden

Depending on the style of garden you wish to design, water can be piped in a natural looking way or maybe by a series of rills would give a more modern, contemporary feel.

Which Plants Are Best For A Rain Garden?

A mixed selection of native wildflowers, rushes, sedges, ferns, small shrubs and/or trees will soak up excess water flowing into the rain garden. The different soil layers filter out pollutants, chemicals and bacteria before the water enters the groundwater system.

Deep plant roots also create additional channels for stormwater to filter into the ground.

By having a variety of plants and vegetation around the rainwater garden gives a good root system which will enhance infiltration and help to maintain soil permeability.Perennial Plants. First Year Flowering

Plant roots also provide moisture redistribution.

Also, rain garden plants return water vapour to the atmosphere.

• Cardinal lobelia. Hardy plants that thrive in sun or part shade, in heavy clay, damp or boggy soils.

  

• Astilbe. These perennial plants have gorgeous plumes of flowers above soft fern-like foliage. They prefer shade and damp soils.

  

• Hostas. Another shade loving and moisture loving plant. They are favoured for their variety in leaf colour and size, easy to grow hardy perennials.

  

• Sedges and Rushes. Although slightly different from each other, both sedges and rushes prefer wet soils and can also tolerate deep shade. They add texture and movement to gardens.

  

• Siberian Iris. Spring flowering Iris that will grow in wet or poor draining areas. They are perfectly happy in low standing water.

  

If like me, you have a generally wet garden or areas of the garden that are more extremely wet than others, then read on for my suggested plant list, some of which are the same as for a rain garden plus some others that I find perfect for growing in wet soils or clay soils

Plants for Wet Gardens.

• Astilbe.
• Hostas.
• Astrantia. Clump forming herbaceous perennials with white, pale pink or deep pink umbels.

  

• Rudbeckia. Hardy perennial plant with bright yellow daisy flowers, flowering well into late Autumn.

  

• Persicaria. These are wonderful ground cover plants with deep green foliage and pink, white or red flowers.
• Cornus Alba. Grown mainly for their deep red stems, Cornus afford all year round interest and look good in informal groups with other winter shrubs such as Hamamelis.

  

• Liquid Amber. A deciduous tree that grows happily in moist but well drained soil, clay, sand or loam. They give all year round interest particularly in autumn when the foliage is deep red.
• Hydrangea paniculata. A deciduous shrub with bushy, lush green growth, flowers from late summer into autumn. Prefers moist, well drained soil.
• Cephalanthus occidentalis. (Button bush) This fragrant shrub prefers full sun and well drained sandy loam.
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My plant suggestions below are for gardens that are naturally more prone to be dry. They are also ideal for a low maintenance garden if one has little time to water plants. Easy Low Maintenance Garden Ideas In terms of the environment, these plants are ideal in drought conditions when we need to look to conserving water.

Plants for Dry Gardens.

• Bearded Iris. They thrive in full sun, flowering throughout summer. Rhizomes need to be planted near the surface in order to take full advantage of the sun – sun baked rhizomes = more flowers.

  

• Sedums. Perfect for dry gardens, sedums require well drained soil with part grit.How to Grow Succulent Plants They need very little attention.

  

• Lavender. This drought tolerant evergreen shrubby plant also thrives in full sun. Beautifully scented flowers appear through summer.

  

• Euphorbia. Their bright, citrus coloured bracts provide colour from springtime through summer. Easy to grow. Always wear gloves when handling these plants, the sap is a skin or eye irritant.

  

• Teasels. Make wonderful architectural features in gardens. Goldfinches and other garden birds feed off the seed heads, making them a favourite for wildlife gardens.

  

• Passion flowers. Beautiful climbing vines with lovely showy flowers. Best suited to sunny, sheltered sites in the warmer regions of the UK.