Rock Gardens - History, Rockery Styles & Plant Ideas

Rock gardens are frequently the butt of jokes, and yes a badly thought out one is more of a carbuncle than a desirable garden feature! But planned, built and planted properly a rock garden can be a thing of beauty in your garden.

Now, this isn’t an article on the practicalities of how to build a rock garden. Au contraire, that is for another time as there are quite a few alternatives and it can get a bit technical! No, this is a starting point for the elements you need to consider when planning to create a rockery in your garden, such as types of rock gardens and plants.

What are Rock Gardens?

Rock gardens, rockery gardens, rockeries – the name isn’t critical, although some would distinguish on size. Rockeries being considered a suburban garden feature; whilst rock gardens and rockery gardens are found in parks, historic and botanic gardens.

But what are they and when were the first ones?

A brief background without delving too far into the history of rockeries: –

‘Modern’ rock gardens are generally considered to have evolved from the grottoes of the 17th and 18th centuries. Although the majority of these were not built for showing off plants but for adding an element of mystery and excitement.
The first rock garden constructed specifically for the growing of alpine plants was probably that created in 1774 for the Chelsea Physic Garden.
During the 19th century, the Victorian gardeners built rockeries for sun and shade. These latter were often ferneries.
Many Victorians combined their passion for travel, to the Alps in particular, and plant collecting with a love of gardening. No wonder rockeries became popular!
‘Pulhamite’ – an artificial substance bearing a striking resemblance to stone, manufactured by the Pulham family. They were renowned for creating a wide range of artificial landscapes during the 19th and early 20th centuries.
One of the oldest and largest rock gardens in the world is that at Kew. Originally constructed in 1882 it has seen various changes, but now has a display which evokes a ‘wild alpine landscape’.
Which leads us onto the ‘Prince of alpine gardeners’, Reginald Farrer. His passion for and plant collecting of alpines enthused the wider public and led to the creation of the Alpine Garden Society.

Rockery or Alpine Garden?

A fairly obvious distinction. An alpine garden contains only alpine plants. A rock garden may not contain any alpine plants, or have a mixture of dwarf varieties, small perennials, bulbs and alpines.

Whilst it is easier to have an alpine landscape where there is plenty of space, not all large rock gardens contain purely alpine plants. Some showcase plants, including trees, from various mountainous and hillside landscapes. This is particularly likely in botanic gardens where the area may for example contain a National Collection or a specific range of plants for research or educational purposes.

In a smaller setting, rockeries can also be used as a display area for particular plants, species bulbs, or alpines. Perhaps those plants which have a connection with the history of the garden.
What is more important than size, is the creation or redevelopment of a rock garden that is in keeping with its immediate surroundings. There are too many suburban mounds of earth with mismatched rocks and plants!

Whether it’s renovating a rock garden, or designing one from scratch, the first question should be: Is a rock garden appropriate? It may be that the similar-yet-different scree garden would better fit the brief.

What else needs to be considered?

Water

Water, whether pond or waterfall, is not essential. For example, if the planting scheme is to replicate a Mediterranean scrub, including a pond could look very odd.

Whereas a shady, damp fernery cries out for a trickling rivulet to add atmosphere. It may be part of an 18th century grotto, a Victorian fern collector’s garden or even a contemporary garden, but done properly it would be highly effective.

If redeveloping rather than purely renovating an established rock garden, it is worth considering options. For example, planting may need a re-assessment. Perhaps what was an open site when first created, suitable for sun-loving alpines, has become shaded as surrounding trees have grown. I’m thinking of Sizergh Castle gardens as the example here (a favourite garden of mine) as by replacing alpines with ferns they were able to showcase part of their National Collection of Hardy Ferns. And remember you don’t need to have a registered National Collection: I know plenty of gardeners who have good collections of a particular species or type of plant.

Terrain

The terrain may be natural or artificial, or perhaps a combination. However, there are three main styles or shapes of rock gardens which are recognised. These are cliff, terrace and outcrop.

Cliff

A steeply sloping site may lend itself to a cliff like rockery where the rocks are supporting the soil and slope. Indeed the rock garden may actually be part of the cliff face with soil added for planting.
On a smaller scale, a drystone wall could be considered to be a mini cliff face, with plants squeezed into gaps. This could be an external boundary wall or internal, dividing up different areas of the garden. Gabions can be treated in a similar manner, planted up for a softer effect.

Terrace

Terracing may be more suitable where shrubs and trees are to be planted, as a greater soil depth can be created. But a small scale terrace will also work, and can be effective as part of a formal garden or adjacent to an alpine house (if you’re lucky enough to have one). Funnily enough these rock gardens can also look right abutting a raised patio or terrace, helping to bridge the gap between the levels.

Outcrop

The digging out of a pond is a frequent reason why outcrop styled rock gardens are created. These can make pleasant features, but are generally more difficult to integrate into level surrounding areas. They look more ‘natural’ when the garden is already sloped.

Why have a Rock Garden?

That is, why should it be restored or a new one created?

Does it fit the period of the garden?

You may be lucky enough to have an older house with an original rockery that may be of historic interest or value. It may need to be recreated exactly or there may be freedom to give the ‘feel’ of the period instead.

Would it be a natural feature in that locality?

This refers back to terrain (above) Using locally sourced rock will look most ‘natural’ and there is certainly a need to keep to the same type of rock within any one rock garden. The type of rock will generally determine the soil type; limestone will give an alkaline soil, sandstone acid soil.

In parts of Britain where limestone pavements are found, the rock garden could be based on this geographical feature. Planting could be native, or alkaline-loving specimens from elsewhere in the world.

Plants, love and science

A rock garden may be present or required because of a love of plants that need those conditions.

Botanic gardens contain a wide variety of plants which may be grouped according to geographical locations and soil preference. One or more rock gardens are a logical addition for them, offering an outdoor laboratory for botanical research.

Alpine houses frequently contain rockeries to better display the plants. These are not going to look ‘natural’ because of being internal, but can give the ‘feel’ of a wild landscape or be there purely for the preservation and display of specimen plants.

Rock Garden Plants

As for the plants to fill the rock garden, there are: –

Alpines – strictly speaking, plants which grow above the tree line in mountainous regions. They may require extra care to protect them from winter wet.

Rockery plants – a generic term given to dwarf plants well suited to a rock garden, regardless of their origin.

And if there is sufficient room, larger shrubs and trees which would naturally grow in mountainous regions.

The rock garden size, rock and soil type, and general aspect will also lead the final plant choice, along with maintenance requirements and personal plant preferences.

One of the common failings in a domestic setting is to have all spring flowering plants for the rockery. This may be due to the desire to recreate alpine meadows seen on a walking holiday or accidental because of buying plants at only one time of the year. It is not an insurmountable problem to resolve, but if starting from new, give yourself a longer season of interest. For example,

have bulbs that flower in each of the seasons
include small evergreen plants with interesting foliage to add texture

Be sure to check that your new plants can tolerate wet British winters or be prepared to cover them up with little glass roofs.

Rock Gardens as Wildlife Habitats

And no, I’m not talking about an overgrown mess! Rockeries provide yet another opportunity for you create a wildlife habitat in your garden. With flowering plants to encourage pollinating insects, crevices for garden spiders to hide in and more, there’s lots of scope.

By adding a scree garden at the base of the rockery or running water trickling down the slope, you increase the wildlife gardening potential. See the blog links below for more ideas

Tiny Gardens and Rented Gardens

When you are seriously short of space and covet a rock garden, you could always make a small one in a container. Sink gardens are the most often seen, but original Belfast and butler sinks are not easy to get hold of.

Why not think about the overall style of you garden and find a container to match? I have seen old lorry tyres used with the soil and rocks heaped to the middle. It was surprisingly effective!
Container gardens are really useful when you’re only renting the property for a relatively short time.

If you would like help with creating or renovating rock gardens do get in touch. Plews is able to offer you Gardening Lessons, Garden Design and Planting Designs or a Garden Consultancy Visit to suit your needs. Please check out relevant pages on the website for more details

For further gardening tips and inspiration check out Plews Potting Shed blogs, including the selection below – and find us on Instagram and Facebook