“If you look the right way, you can see that the whole world is a garden.”

Wise words from Frances Hodgson Burnett in her much loved novel The Secret Garden.

A country lane in Devon, UK

Certainly spring in the countryside of Devon, in the South West of the UK, lives up to this. Narrow country lanes are flanked with exuberant vegetation.

A Linear Garden

All the elements of a garden are found here, with blocks of different colours and plants with architectural beauty each enjoying their season. The dark-leafed form of Anthriscus sylvestris, commonly known as cow parsley, is even found in the trendy gardens while the green bears clouds of white flowers that are delightful to see as you drive around.

Cow parsley, Anthriscus sylvestris, gleaming in bright sun

Few gardeners pay much attention to the natural planting outside their garden gates; the plants ‘out there’ are coarse and unrefined, and most would cause havoc in the garden.

Brutish Bullies

Most hedgerow plants are strong growers.

They have to be; if you’re trying to hold your own against neighbouring plants you must be tough. Some plants, orchids a fine example, occupy niches that few other plants exploit, while others must thug it out with their neighbours for space to grow.

Apart from the ferns, possibly, there’s nothing here you’d want to introduce into a garden

Few garden plants would be able to compete with the barbarian plants from beyond the garden’s borders. Most of the delicate little things we cosset and cultivate would easily be overwhelmed by coarse grasses, nettles and other feared garden weeds.

A Question

Why are garden plants so weak that they wouldn’t be able to hold out against the local thugs?

The answer is complex, but fundamentally gardeners tend to gravitate towards novelty. We don’t relish the plants that would be the most successful in our climate because we want to enjoy lots of exotic plants from other places.

The sword-like leaves belong to some crocosmia dumped in the hedge

I’m not saying for a moment that this is wrong; we grow lots of things so that we can enjoy colour and beauty for a longer period. This desire for beauty is a cornerstone of gardening.

We sometimes find ourselves drawn to plants that have the beauty of a cultivated plant but the boisterous tendencies of a wild plant. These are the exotic plants that gardeners say are “too invasive” for their gardens. (In the UK this would be Symphytum (comfrey), the American Onoclea sensibilis (sensitive fern) and the suchlike; you’ll have similar aggressively spreading plants that you know of.)

Tough Plants

Whether or not a plant is ‘invasive’ can often come down to perspective.

It’s fair to say that any non-native plant that escapes the garden (or is dumped in the natural environment) and goes on to thrive is ‘invasive’, but even here there’s nuance. A dumped garden plant that grows in the same space for decades, failing to spread much beyond its original location, is far less ‘invasive’ than a plant that spreads quickly over a vast area and outcompetes local plants. Both should be treated seriously, but one is a far more urgent threat than the other.

Alkanet, the blue flowered plant, is not native to the UK but has become widely naturalised

Likewise if a native species comes into the garden and spreads then it might be regarded as ‘invasive’, and then there are those plants alluded to that we plant in good faith but which then spread beyond expectation.

American readers might recognise Tellima grandiflora, a tough American plant that is naturalised here

In my area we have the American plant Tellima grandiflora, commonly known as fringecups, appearing in gardens and wild spaces. It’s not supposed to be here but at the same time it doesn’t really cause much trouble. By contrast Allium triquetrum, three-cornered leek, is a Mediterranean species that causes absolute chaos in gardens and wild spaces.

Lesson Learned

A tough plant, like those found in the hedgerows near my home, grown with other tough plants will find an equilibrium; sometimes a species gets the upper hand but soon enough something will knock it back and other plants seize the opportunity to spread. Unless the balance is tipped dramatically, a balance is struck.

I took an early morning walk along this road to take pictures for this piece

Introducing strongly growing plants can upset the balance of the garden, leaving the gardener having to work hard just to stop the new plant from causing problems. This is partly because we tend to grow plants that are a little less vigorous but give us a more aesthetically pleasing effect.

Nurseries give us information about the height and width of the plant, but to create and maintain harmony in our gardens it would be helpful to know the pace of growth.

What if rather than removing nettles you could just grow something that would slow their spread?

An example: you have two herbaceous perennial plants that grow 3ft (1m) tall and 2ft (60cm) wide. The first plant will reach 3ft by 2ft in 10 years, the second will reach the same size in its second year. Which is likely to be the more aggressive plant?

The second one of course; a plant that makes a 2ft spread in two years isn’t going to suddenly stop spreading outwards. If you planted these two plants together you would find that the second plant overwhelms the first.

Can You Make A Garden With These More Vigorous Plants?

If you grow solely more vigorous plants in your garden then they will find the same equilibrium as the plants in the hedgerow near my home do. You won’t need to buy quite so many plants to fill the space, and you can still have a fantastic garden.

But, and I cannot stress this enough, if you adopt this approach don’t then go planting less vigorous plants among your brutes. Keep a special area of the garden for smaller and more dainty plants by all means, but keep in mind the pace at which plants grow rather than solely the height and width.

English bluebells are admired and revered in the UK, but they’re surprisingly tough and could be considered a nuisance in gardens

It’s also vital that we accept a moral obligation not to grow plants in our gardens that will cause a nuisance beyond our hedges or fences. Our neighbours might not appreciate our taste in plants, and we certainly shouldn’t risk our garden plants escaping into nature. This is as much a message for readers in the UK and elsewhere in the world as is for American gardeners.


Plants grow differently according to local climate and soil conditions, so actually quantifying the pace of growth could prove challenging.

However by understanding how plants work together, and understanding how to group plants to utilise their ability to keep each other in check, it’s possible to work with larger plants more effectively. By avoiding the ‘small’ and ‘compact’ plants at the nursery you will be able to create a fine garden

Early morning sunshine on Anthriscus sylvestris. This ensemble could be an exhibit at the Chelsea Flower Show!

Shouldn’t I be encouraging everyone to go out and buy more plants? Well it would be nice to do that of course, but not everyone has the budget to spend lots of money on their gardens, and not everyone has the time to tend lots of different plants in a more complex garden. It’s important to know our options.