Guidance For Flood Gardeners

Posted on: 19 February 2009 by Gareth Hargreaves

Around five million people in England and Wales alone are at risk of flooding, garden writer Maxine Farmer offers budding gardeners some much needed expertise.

Recent rain and melted snow have had a dramatic impact on many people recently and while nothing can compare to the misery of a flooded home, it can be pretty devastating for keen gardeners to watch their precious plots being wrecked by flood-water, or simply by being waterlogged for months on end.  

Nor is planting moisture-loving species the answer, because when summer arrives, we are rightly being told to be ‘water-wise’ and abandon our hoses and sprinklers.  So we’re torn between two extremes. 

Fortunately, it is possible to have a garden that can survive soggy soil one season and dry the next.  How do I know?  Because since 1995, my husband and I have lived on a plot that floods on average once a year and has a very high water-table for months on end. 

Then, in the summer, the clay soil – mixed with a big dose of chalk – turns into a big baked pan of grey earth.  Despite that, and modesty aside, our garden is much admired and has been featured in the national and gardening press.

Good News

It hasn’t been easy, but I’ve spent years researching and experimenting with plants and techniques that will survive the increasingly volatile UK climate.  

As a garden consultant and writer, I’ve been fortunate in being able to access sources that have helped me identify which plants will ‘sink or swim’, as well as the most effective ways to improve the surrounding environment.  

So what advice would we pass on to fellow gardeners?  We’ve created a web site to share lots of free information at but here are just a few suggestions.

Improve Drainage

Improving soil drainage is essential: the faster water is encouraged to get out of the way of plant roots the better. 

Check that there are no areas of impacted soil.  This is literally earth that has had the air beaten out of it, often by people walking on it or as a result of building work. 

Flooded gardenPut the ‘heart’ back into the soil by turning it over and – especially if it’s heavy clay  – add grit and fibrous material, such as leaf-mould or even spent compost and grow bags to create a lighter, airier consistency.  Every spring, ‘top dress’ the soil with a similar mixture, which the worms will gradually pull into the sub-strait.

Raised beds improve drainage and dramatically improve the range of plants that can be grown successfully.  We have found that even a raised bed of just six inches is enough to make a big difference, because water is allowed to drain away once flood water starts to recede, rather than sitting around the necks of plants. 

For instance, we found that phormiums (New Zealand Flax) cannot survive in our garden when planted at normal ground level, but have thrived in raised beds and even in large pots. 

For more extreme situations, options include field drainage pipes, soakaways and cut-off ditches.  These can be costly and can require external expertise, but may be the only option. 

Where standing water is not necessarily a problem to surrounding houses, why not turn a problem into a feature?  We gave up trying to drain a particularly boggy part of the garden and turned it into an artificial ‘stream’, colonised by ferns, woodrush, iris sibirica and a low-growing native lotus. 

Choose The Right Plants

Choosing the right plants in the first place makes all the difference.   Fortunately, I’ve discovered that there is an amazing range of plants that will cope with wet and dry extremes, most of which are readily available.

Good garden design benefits from a strong backbone and excellent shrubs for wet-to-dry environments include Cornus Sibirica, a member of the dogwood family that makes a handsome fast-growing shrub with red stems in winter.

For something smaller, try the spiraea family of shrubs, which are happy in sun or shade and apart from light pruning, need little care.  Most of the viburnum family copes well in garden extremes, particularly the deciduous kinds (lose their leaves in winter), but the evergreen viburnums are borderline survivors of floods. 

Indeed, few evergreens can cope with regular submersion, but there are some exceptions.  Examples include lonicera pilata, that hard-working, ground-covering shrub, and the dramatic mahonias.  For something a touch more exotic, try the non-invasive bamboos Fargesia Murielae, which has delicate filigree foliage ideal in light shade.

Flower Power

The choice of flowering perennials and grasses for garden extremes is vast and includes some plants that are known to do well in dry soils – such as crocosmia, solidago, sedum spectabile – but also cope well with wet winters. 

Although most plants that naturally prefer moist soil do not fair well in drought conditions, some are quite well adapted, including filipendula ulmaria (the native Meadowsweet), hemerocallis (the Daylily), iris sibirica and lythrum salicaria (Purple Loosestrife). 


Increasingly, gardeners are mixing grasses among their flowering plants and although many prefer dry and free-draining soil, I have found that most carex (sedge) varieties fair well, though check the pH as some cannot cope with very alkaline soil. 

A favourite grass of mine is the majestic Miscanthus Sacchariflorus, which each year sends up sturdy stems up to eight feet high.  Miscanthus sinensis is a touch daintier and smaller: hunt out Miscanthus Sinensis ‘Gracillimus’ for its fabulous dusky pink seed heads in autumn.

There are far more plant choices I could mention: ferns, exotics, acid-lovers, suitable trees, shrubs and perennials, even edible plants – the list goes on!  And that is the good news for gardeners: there are enough species that will survive the extremes of wet and dry to suit just about any plot. 

The key to their survival is choosing the right plants in the first plant and then, giving them the most hospitable home possible.

By Maxine Farmer

About The Author

Garden writer and consultant Maxine Farmer has had articles published in The Daily Telegraph, Housebuilder & Renovation, and the RHS’ members magazine, The Garden.

Maxine has created a website ( that includes lots of useful free information, including details of how to obtain her free fact sheet containing a list of plants.  You can also email her at for more information.

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