What plants go in a rain garden?

Welcome to the second article in our rain garden blog series. In this article, we will go over what the best plants are to plant in a rain garden, along with where they are best positioned. 

Choosing the right plants is one of the most important steps in building a successful rain garden. Because rain gardens cycle between wet and dry conditions, plants must be able to tolerate both occasional flooding and periods of drought. 

The key is to match plant types to the moisture zones within the rain garden. 

Understanding rain garden plant zones 

A rain garden typically has three moisture zones: 

Bottom zone (wettest): Holds water the longest after rainfall

Middle zone (moderate): Drains more quickly but still receives regular moisture

Perimeter zone (driest): Rarely saturated except during heavy storms 

Selecting plants based on these zones improves survival rates and reduces maintenance. 

Native plants vs. non-native plants 

Whenever possible, prioritise native plants. They typically: 

• Have deeper root systems 

• Require less maintenance 

• Support local wildlife 

• Adapt better to regional rainfall patterns 

Non-native ornamentals can be used selectively, but avoid invasive species and shallow-rooted plants that provide little filtration benefit. 

All the plants suggested in this article are native to the UK. 

Plants for the bottom zone

The lowest part of the garden needs plants that tolerate temporary standing water and saturated soil. 

Good choices include: 

Moisture-loving native grasses, sedges and rushes 

• Carex pendula - Pendulous sedge 

• Juncus effusus - Soft rush 

• Carex riparia - Greater pond sedge 

  
  

  Wet-tolerant perennials 

• Iris pseudacorus - Yellow iris 

• Caltha palustris - Marsh marigold 

• Lythrum salicaria - Purple loosestrife 

  
  

  Ferns (in shady areas) 

• Athyrium filix-femina - Lady fern 

• Dryopteris dilatata - Broad buckler fern 

• Dryopteris dilatata - Broad buckler fern 

  
  

Look for species commonly found near streams, wetlands, or low meadows in your region. These plants are adapted to fluctuating water levels and help maximise absorption through extensive root systems. 

Plant the most flood-tolerant species here, spacing them densely enough to stabilise soil and reduce erosion. 

Plants for the middle zone 

The middle zone experiences periodic soaking but drains faster than the centre. This is where many versatile garden plants thrive. 

Strong candidates include: 

Flowering perennials 

• Ajuga reptans - Bugleherb 

• Campanula glomerata - Clustered bellflower 

• Filipendula ulmaria - Meadowsweet 

  
  

  Ornamental grasses 

• Deschampsia cespitosa - Tufted hairgrass 

• Molinia caerulea - Purple moor grass 

• Festuca rubra - Red fescue 

  
  

  Hardy shrubs 

• Cornus sanguinea - Common dogwood  

• Viburnum opulus - Guelder-rose 

• Frangula alnus - Alder buckthorn 

  
  

This area is ideal for mixing colours, bloom times, and textures. Choose plants with varying heights to create structure and visual interest while still supporting water infiltration. 

Plants for the perimeter zone

The outer edge should be planted with species that prefer normal to dry soil conditions but can handle occasional heavy rain. 

Best options include: 

Drought-tolerant perennials 

• Achillea millefolium - Yarrow 

• Knautia arvensis - Field scabious 

• Lotus corniculatus - Bird’s-foot trefoil 

  
  

  Meadow flowers 

• Leucanthemum vulgare - Oxeye daisy 

• Centaurea nigra - Common knapweed 

• Silene dioica - Red campion 

  
  

  Small shrubs 

• Calluna vulgaris - Heather 

• Ulex europaeus - Gorse 

• Lavandula angustifolia - Lavender 

  
  

  Tough border grasses 

• Festuca ovina - Sheep’s fescue 

• Briza media - Quaking grass 

• Anthoxanthum odoratum - Sweet vernal grass 

  
  

These plants help transition visually from the rain garden to the rest of your landscape. They also stabilise the edges and reduce soil wash-in during storms. 

Final planting tips 

• Group plants in clusters for stronger visual impact 

• Mix root depths for better soil structure 

• Plan for year-round coverage 

• Water regularly during the first growing season 

  
  

With thoughtful plant selection and placement, your rain garden will not only manage heavy rainfall effectively but also become a resilient, living feature in your landscape. In the next article, we can explore layout and installation step by step. 

If you think your garden might be suitable for a rain garden, don't hesitate to get in touch! We would love to start installing rain gardens and documenting the impact they have.