Last Modified: April 5, 2024

Creating Rock Gardens with Plants

DIY Guide for Rockery Construction

How to create rock gardens with plants

By Ben Parrot - Landscape Gardener & Amateur Geologist

Overview

Welcome! You're about to build your own rock garden, a zen-like space full of aromatic foliage, decorative pebbles and unique groundcovers. As a hardscape project, it's really not that hard, but to get a good result does require a bit of planning. Start by taking a look at your garden area, making a note of the main colours, and considering what kind of space you have. Is there loads of sun or just a bit? Even the smallest little snugs can be turned into beautiful little landscapes with the right rocks and plants.

A quick heads-up regarding our freshly introduced tool, the 'Pebble Picker', accessible in the sidebar or menu. It streamlines the task of viewing and comparing decorative aggregates, organised by colour and type, for your convenience.

Rock garden planting scheme

A schematic of a rock garden planting with soil profile.

Now, start imagining how your rocks will sit in your garden, and for rock garden plants, consider using alpine species such as saxifraga, sedum, or thyme. Along with drought-tolerant succulents, these plants thrive in rocky, well-draining soil, adding vibrant colours and textures to your garden, contrasting the grey hues of pebbles and rocks.

In this article, we go through the stages of creating a rock garden with plants, covering all you need to know, including a range of grasses and plants suited to different conditions, be they full sun or shade-loving. Ok, get ready to rock (garden)!

Key Takeaways

  • Planning: Find out about proper planning which is the cornerstone of a successful rock garden.
  • Drainage: Learn about the importance of drainage, which is key to plant health in rockery gardens.
  • Conditions: Assess the soil and sunlight conditions, which are essential to selecting your plants.
  • Selection: Get a selection of the right plants to suit the aesthetics and conditions of your rock garden.
Scottish heather growing in a shingle garden

Planning the Layout of Your Rock Garden

Designing a rock garden is like making a blueprint for a house. You need to consider space, sunlight, and existing outdoor garden features. When choosing a spot for your rock garden, consider how much sunlight the area gets during different times of the day. 

Location, Location, Location

Plants for rockeries often thrive in full sun, so finding an area that receives at least 6-8 hours of light per day is best. If your garden space consists of both sunny and shady areas, it's ok, but it's important to properly plan where to place plants that require different light levels. The good news is that there are beautiful, shady rock garden plants, like Siberian dogwood (Cornus alba 'Sibirica') and yellow foxglove (digitalis grandiflora), ready to beautify your less sunny areas.

Also, consider your existing landscaping features, including any natural rock formations, and how your rockery can work with them. For example, if there's a sloped area that could be decorated with pebbles and the ideal types of plants for rockery gardens, choosing there - or an area where other plants struggle to grow - might be the perfect spot.

Cacti and succulent garden with black basalt

Draw a Skeleton Plan

Once you've identified the location for your rock garden, it's time to create a skeleton plan, which is a rough sketch that will set out the placement of rocks, gravel and plants. Incorporating elements like boulders, lights or a small water feature can add interest and draw the eye, while walkways can create a sense of flow in larger installations. While sketching the layout, try to imagine how different plants will fit into the design in a way that is complementary to both the rocks and each other.

With careful consideration of sunlight, existing landscape features and pathways, you're well on the way to creating your stunning rock garden. Good drainage is an important aspect that we will cover next.

Drawing a skeleton plan with pen ruler and sketchpad

Consider Drainage When Planting Your Rockery

No matter where you place your rockery, proper drainage is essential. If your garden is in a low-lying area that is prone to flooding, grading the ground can help direct water runoff to prevent pooling around your plants. The good news about incorporating gravel, small stones or coloured pebbles into any garden is that it aids in effective water drainage. Landscaping fabrics are also a great addition to improve drainage.

Crevice Gardens

Crevice gardens are a unique and visually striking type of rockery garden. They consist of narrow crevices between rocks, which create pockets for planting. This style of garden is ideal for growing alpine and rockery plants, as the crevices provide the perfect conditions for their growth.

To create a crevice garden, choose rocks with irregular shapes and sizes to form the crevices. Place the rocks in a way that allows for maximum sunlight exposure and proper drainage. Fill the crevices with a well-draining soil mix, and carefully select plants that are suitable for this type of environment. Crevice gardens can add depth and interest to your landscape, making them a popular choice among garden enthusiasts.

Plants growing in between rocks

How to Build a Rockery in Shade

When building a rockery in a shady area, it's important to choose plants suited to low-light conditions. Opt for shade-loving alpine and rockery plants such as ferns, mosses, and certain varieties of sedums and saxifrages. These plants are well-suited to the cool and damp environment found in shaded rockeries. Selecting rocks that are lighter in colour can also help to brighten up the space. When positioning the rocks, consider the natural direction of sunlight and try to place them in a way that provides some pockets of light throughout the day.

Landscaping Fabric

The addition of a non-woven landscaping fabric will also improve drainage whilst keeping gravel separated from the soil below. On top of that, it will keep the feature low maintenance by suppressing weeds and their seeds from taking hold, which can be a problem in gravel gardens due to the friendly nature of gravel as a growing medium.

As we continue navigating the intricacies of designing an exquisite rock garden, we now turn our attention towards the selection of the rocks that form the foundation of your feature. From mammoth boulders to cobbles or decorative gravel, they are the dance partners of the plants for a rockery garden. The selection of rocks is crucial for achieving an authentic and visually appealing landscape. Here's what you need to consider when choosing rocks for your garden.

Landscaping fabric close up

Selecting Your Rockery Rocks

A garden rockery blossoms on variety, and each type of rockery stone brings its own unique character to your plan. Slate is a mainstay of rock garden design, with plum slate rockeries world renowned. Granite, known for its stunning character and weather resistance, comes in various colours, such as green, grey, pink, and black. Limestone is lighter in colour and easy to shape. It can contribute to a natural look in the garden. Sandstone also comes in a diversity of colours and textures, ideal for adding visual interest and depth.

Plum slate chippings and green granite gravel

What Rocks are Best for Rockery?

Incorporating rocks of varying sizes and shapes, just as you would when selecting shrubs and trees, is key to creating a dynamic and attractive scene. Large rocks can create focal points, while smaller ones can be placed between them for contrast and the creation of planting pockets. This creates microclimates for different types of plants and insects. Here are some

  1. 1
    Sandstone: Popular for rockeries due to its natural beauty and range of colours, including red, yellow and brown.
  2. 2
    Granite: A strong and sparkly rock that is available in colours from black and grey to green and pink.
  3. 3
    Limestone: Another good rock because it is easy to work and has a light colour that can brighten up a space.
  4. 4
    Slate: Fine-grained rock that is also fish-friendly, making it a practical choice for rockeries with water features.
  5. 5
    Quartzite: A metamorphic rock that comes in various colours and patterns and is highly durable.
  6. 6
    Basalt: Dense, dark rock commonly used in rockeries for its durability and ability to withstand weathering.

The interplay of large and small rocks can be used to complement the diversity of plant life in your garden, providing niches for species to stand out. Imagine, a patch of Lungwort 'Blue Ensign', infusing itself into your backdrop with splashes of green and bursts of purpley-blue, all framed by a well-placed rock arrangement.

Ultimately, the best rocks for rockeries will depend on your garden's specific aesthetic and practical needs. There is also great scope for customisation using the colours of decorative aggregates.

Placing green slate boulders in a garden

The Colours of Gravel

Another option is using decorative aggregates, which can add texture and colour to your rockery. These include gravel, pebbles and cobbles, which come in different sizes and hues to complement your overall design. Now, to the fun part – choosing your gravel! The variety of outdoor aggregates in the UK is extensive, and our site significantly increases the availability of this range to UK homeowners.

The good news is that with our encyclopaedia of decorative aggregates, you can browse through a comprehensive list covering almost every type and size of bark, stone chippings and gravel that can be found in the UK. Each entry provides detailed information in a straightforward and helpful way. If you have spotted the colour picker in the sidebar but haven't clicked on it yet, it's also a simple and effective method to find options based on colour and material. If you haven't tried it yet, feel free to give it a go!

Decorative angel ornament for garden

Aesthetic Additions

A rock garden can be further embellished by adding decorative features like slate water features, stepping stones or sculptures. These additions can add depth and character to the landscape while complementing the natural beauty of the rocks and plants. Stepping stones and coloured, decorative gravel can add striking charm to your garden while guiding visitors on your geological journey.

Decorative angel ornament for garden. Jpg

Assessing Growing Conditions

Before planting anything in your garden, understanding the conditions under which plants will be grown will significantly influence the types that will be optimal for your gravel rockery. The main aspects involve assessing the soil and sunlight in your garden.

Start by measuring the soil pH. Most alpine plants, ideal for rock gardens nestled among boulders and stone walls, thrive in well-draining, slightly acidic soil. The ideal pH range for rocky plants, variations of alpines and sedums is somewhere between 6.0 and 7.0. You can easily obtain a soil testing kit online or from a garden centre.

1ph testing strips on soil

Soil Analysis

Let's use an analogy to understand this better: Just like each plant has its own nutritional needs, (think of them like the varying health requirements of adults and children), they also have specific preferences when it comes to soil chemistry. It's like identifying a good recipe for each of your plants — some may revel in moisture-rich and slightly alkaline conditions, like the pasque flower, Japanese Pulsatilla Vulgaris, while others, such as Dianthus (Dianthus caryophyllus), can grow in drier, more neutral pH.

Do rockery plants need soil?

Yes, to establish a successful rockery, free-draining soil is necessary. The type of garden designed to showcase small or alpine plants is best with well-drained soil. By incorporating a mixture of grits and larger stones with a selection of suitable rockery plants, you can create a hardy and stunning feature. The key to the health of any rock plant lies in the soil's ability to provide adequate drainage, emulating their ideal environment to grow.

1spring bulb growing up through grey gravel

Sunlight Exposure

Evaluating the sunlight patterns in your garden to determine which areas receive full sun, partial shade, or full shade is the other main issue when selecting the best plants for rockeries. You can often tell by what has previously grown in the spot where you plan to build.

In essence, taking the time to understand these two critical components—soil analysis and sunlight exposure—will lay the foundation for a thriving and visually stunning rock garden. The moisture, light, and soil conditions can dictate whether a Pasque flower or Dianthus best suits a specific area, for example.

The Timing and Arrangement of Plants

During the arrangement phase of establishing a rock garden, some prefer planting a rockery garden at the same time as planting the rocks, inserting them bit-by-bit. At the same time, many choose to add their rockgarden plants just after the construction phase is completed.

In our opinion, the advantages of following a methodical plan and waiting until the construction process is over to sew your garden rockery plants far exceed the alternatives. It allows for an easier time with construction and offers greater flexibility.

For starters, the construction phase can take as little or as long as you want. Therefore, if you want to wrap things up fairly quickly, watering in plants as you go can quickly cause the site to become muddy and harder to work. However, building some flexibility into your plan is also always good.

Once you have reached a certain stage, you may find that you want to put your plants, objects or stones in a different place than you first envisaged. That will result in disturbing the plants during a crucial time, causing them an undesirable amount of stress - and plants aren't cheap these days! There is also the increased chance that plants already set into their new homes could get trampled on during construction.

1blue slate chippings rockery with shrubs

Leisurely Flexibility - The Genius of Play

When the construction is completed first, your inner child can come out and play around with the plants and their positions. This means you can rearrange at leisure, getting a much better overall picture before final planting. At this stage, the plants' preferences for crevices or flat ground, sunny or shady positions and soil requirements should all be kept in mind (refer to the plan you made for the specifics) if you intend to move them too far from the original place.

If you have the time, consider delaying the planting for a couple of weeks, which will give the rocks and soil time to settle. This will allow you to fill any cracks and depressions that naturally appear under rainfall or simulation by the use of a sprinkler for a few hours.

Now that we've covered selecting your garden rocks and the pros and cons of when to incorporate your plants let's move on to the species that harmonise with rockeries in gardens and their arrangement.

1plum slate stacked water feature

Need to work out how much gravel your project needs? Try our free gravel calculator.

Plant Placement in a Rock Garden

The first thing to consider when deciding on plant placement is layering. Just like a rockery that may have the taller Pulsatilla Vulgaris towards the centre and smaller Dianthus towards the borders, this method creates a sense of depth, making your garden feel more alive and vibrant.

Next up, let's think about highlighting focal points. As one example, a snow-in-summer (Cerastium tomentosum) placed near a larger rock within the rockery. This creates a harmonious arrangement that engages visual interest across the garden. Now, let's talk about creating contrast with varying leaf textures, colours, and forms of the Pasque flower and the bellflower (Campanula). This can help to create an area full of life and interest, texture and harmony.

All of your choices need to be taken into consideration before planting anything in your rock garden. When it comes to selecting plants for a rock garden, you want ones that are visually appealing and suited to your garden's specific conditions.

1succelents and palms in a slate and gravel rock garden

Recommended Plants for Rockery Gardens

Low-growing perennials, alpine plants, dwarf shrubs and ornamental grasses are some of the best choices due to their adaptability and visual appeal. When thinking of rock garden ideas, fragrant lavender, feathery yarrow, and tufted grass species are fantastic choices. Bulbs offer seasonal beauty and fragrance, while groundcovers fill voids beautifully.

Native Plants

It's also beneficial to consider whether your selected plants are native species. Native plants are well-suited for the local climate and soil, requiring less maintenance because they have adapted over time and are generally more resistant to local pests and diseases. Choosing native also aligns with sustainable rock garden ideas by reducing water consumption and minimising the need for fertilisers and pesticides. They promote biodiversity by providing habitat and food sources for indigenous wildlife such as birds and pollinators like bees and butterflies.

1pink and yellow garden flowers

Alpine plants

Alpine plants are a great choice for rockeries due to their adaptability to rocky and mountainous environments. These plants are often low-growing, hardy, and able to withstand harsh conditions such as high altitudes, strong winds and poor soil quality. Some popular alpine plants suitable for rockeries include saxifrages, sedums, creeping thyme, and mossy saxifrages. Other options include dwarf conifers, such as junipers and spruces, which add structure and texture to the rockery. These plants offer a range of colours, textures and foliage types, adding diversity to the rockery garden.

1perennials and grasses in a gravel garden

The Best Compost Mix for Alpines

When it comes to choosing the best compost mix for alpines in your rockery garden, it's important to consider their natural habitat. Alpines grow in well-draining soil conditions, so a mixture that provides excellent drainage is essential. A suitable compost mix for alpines can consist of equal parts of garden soil and coarse sand, grit or perlite to improve drainage. This allows excess water to quickly drain away, preventing root rot and promoting healthy growth.

Adding a small amount of organic matter, such as leaf mold or composted pine needles, can provide essential nutrients to your alpine plants. Avoid using heavy or clay-heavy soils, as they can retain too much moisture and harm alpines.

In the next section, we will cover some great plants for rockery gardens and follow it up with recommendations of some ornamental grasses and rock garden plants for shade positions.

1natural leaf mold breaking down

Plants for a Rockery With Full Sun

Sedum, with its low-growing nature, drought tolerance, ease of spreading, and even the grass-like structure of some varieties, is an excellent option for a rock garden. It requires minimal watering and occasional pruning, making it a low-maintenance choice. Its small star-shaped flowers in various colours add visual appeal to the garden.

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    'Icicles' (Helichrysum)
  2. 2
    'Greenfingers' (Choisya)
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    'Purrsian blue' - catmint (nepeta faassenii)
  4. 4
    'Jenny's stonecrop' (Sedum reflexum)
  5. 5
    'Nanum' (Pittosporum tobira)

Additionally, Penstemon, bulbs and 'Wild Thyme' (Thymus polytrichus) are great options due to their hardiness and vibrant blooms.

2snowdrops growing around granite boulders
2young plant purrsian blue nepeta
2fresh thyme

Plants for a Shady Rock Garden

When we talk about the types of plants for shady rock gardens, it is implied that we mean partial sun. If you have an area that receives little to no sun, the choice of plants becomes far more limited. One example is 'Moss Phlox' (phlox subulata) is a groundcover renowned for its carpeting ability and resistance under dry conditions. Once established, it requires minimal watering while adding vibrant colour to your rock garden with its pink or white flowers. Here are some other great options:

  1. 1
    'Italian bugloss' (Anchusa azurea)
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    'Royal purple' (LIRIOPE MUSCARI)
  3. 3
    'Fountain bamboo' (Sinarundinaria nitida)
  4. 4
    'Aubrieta false rock cress' (Aubrieta deltoidea)
  5. 5
    'False lupin' (Thermopsis montana)
2bamboo growing in a garden

Rockery Grasses

Rockery grasses offer resilience, texture, and colour, making them ideal for rockery landscaping. These hardy plants thrive in stony terrain and introduce a serene elegance and texture to garden spaces. From blue fescue to bearskin fescue, they enhance biodiversity and add architectural grace to your rockery.

  1. 1
    'Golden oat grass' (Stipa gigantea)
  2. 2
    'White sands' (Lomandra)
  3. 3
    'Intense blue' (Festuca glauca)
  4. 4
    'Ponytails' or 'Mexican feathergrass' (Stipa tenuissima)

As you immerse yourself in selecting the perfect plants for your rock garden, considering both aesthetic appeal and practical benefits is essential. A well-chosen combination of low-growing perennials and native species contributes to the beauty of your rock garden while providing long-term sustainability and support to the local biodiversity.

With a strong foundation laid on selecting the right plants for your rock garden, from bright bulbs to lush grasses, now let's turn our focus to the way to plant your rock garden vegetation.

2 white sands lomandra decorative grass
2ponytails stipa tenuifolia decorative grass

How do you plant rock garden plants?

To plant your rock garden plans simply and effectively:

  1. 1
    Begin by thoroughly watering your plants while they're still in their pots.
  2. 2
    Position them within the garden according to your plan, considering their ultimate height and spread to make sure that they have ample space to mature.
  3. 3
    Dig a hole that is slightly larger than the volume of the pot. Add some compost at the base.
  4. 4
    Gently remove the plant from its pot, carefully loosen the roots to encourage growth, and clear away any weeds on the compost's surface.
  5. 5
    Water them in well.

Repeat this process until you have transplanted all of the plants so they are ready to thrive in their new environment, your new, vibrant rock garden. Congratulations, you have built your amazing rockery garden!

2shade loving plants

Expert Tips for Creating a Rockery

We can start with the placement of rocks. Keep rocks at an angle, as it's better for drainage and stability. It also creates a more natural look. We also have some tips on testing the soil pH, crevice planting, and a couple more.

Test Soil pH

To determine the acidity of soil, it is recommended to conduct a pH test using a soil testing kit. The pH scale ranges from 1 to 14, with neutral being at 7. Most garden soils have a pH between 5 and 8, and readings between 4.5 and 6.5 indicate acidic soil, while readings above 7 are alkaline. Soil testing kits are widely available and inexpensive. The pH is determined by comparing the colour to a chart: bright green for neutral, yellow or orange for acidic and dark green to blue for alkaline. To get an accurate reading, multiple samples should be taken from different areas.

Crevice Planting

Vertical gaps between rocks can be used to grow different types of crevice-dwelling plants. It is best to select young and small plants that can be easily planted. Planting in crevices involves placing plants in small gaps or cracks in walls, rocks, or other surfaces. This technique is used to create a natural and organic look.

2spring daffodils growing between granite boulders

Choosing the Best Place

It is worth steering clear of putting a rough and natural rock garden formation too close to more formal parts of your garden, such as flower beds, green borders and rose gardens. Suppose your rockery is to be bordered by turf. In that case, it is also more visually pleasing to create an intermediate zone using small stones and grasses instead of having the rocky outcrop abruptly rising up right next to the neatly trimmed edge of your lawn.

Wait for the Dust to Settle

Patience and timing are key when it comes to creating a successful rockery garden. It is advisable to wait a few weeks after building before planting to allow your stones and soil to settle. This will aid in filling any crevices or hollows with additional soil. If there is no rainfall, using a sprinkler for a few hours to simulate rain can hasten the settling process.

2large cacti with black basalt chippings and rocks

Summary

In conclusion, this step-by-step guide has provided you with a comprehensive understanding of the process, from the initial planning stages to the final touches. We've explored the importance of selecting the right location for your rockery, considering factors such as sunlight exposure and drainage. We've also delved into the process of choosing rocks that not only complement your garden's overall design but are also suitable for your region's climate conditions.

The guide has highlighted the significance of preparing the ground adequately to ensure a stable foundation for your rockery. We've discussed how to arrange rocks in a natural-looking manner, creating an appealing balance between size and shape. Furthermore, we've examined how to select plants that will thrive in a rockery environment, adding colour, texture and life to your garden.

Building a rockery garden may seem like a daunting task at first glance. However, with careful planning, patience and creativity, it is entirely achievable even for beginner-level gardeners. Remember that it's not about creating a perfect rockery overnight but enjoying the journey of transforming your garden into a unique landscape over time.

We hope this guide has inspired you to embark on this exciting gardening project. With its blend of rugged beauty and low-maintenance appeal, a rockery garden can be an excellent addition to any home. So why not roll up your sleeves this weekend and start building your very own rockery? Happy gardening!

2sandstone garden rockery with grasses and shrubs

FAQs

How do I make a rock garden?

To create a rock garden, first find a suitable location and plan the design, choosing a colour scheme that works with your house's exterior. Next, consider the size and use native rocks where desired. Measure the area to calculate the materials you will require. Once you have everything you need, clear the site, adding your rocks and spreading your weed membrane and soil over the surface. Lastly, position your plants and add any decorative touches.

What is a rock garden called?

A rock garden, traditionally referred to as a rockery or rockwork, is a distinctive garden-style characterised by the purposeful arrangement of plants among rocks, stones and gravel. This setup is designed to accommodate and frame plants well-suited to rocky environments, often including small alpine species that require minimal soil and water. The rock garden's structure provides a visually appealing feature while creating a specialised habitat for these unique plant varieties.

What is the difference between a rock garden and an alpine garden?

The difference between a rock garden and an alpine garden is determined by the specific plants that each garden type employs. While an alpine garden is a type of rock garden focused on plants native to high mountain environments, a rock garden can include a broader range of plants suited to native or rocky landscapes. Alpine gardens aim to emulate the conditions of mountainous regions, showing plants adapted to high altitudes.

When should I plant rockery plants?

The best time to plant rockery plants is during spring. Spring planting affords plants the best opportunity to establish their root systems and acclimate to their new environment throughout the growing season. This also ensures that they are best prepared for the colder and wetter conditions of winter. Although the construction of the rockery itself can be undertaken at any time of the year, spring planting is ideal timing for the long-term success of your rock garden.

What is the best ground cover for a rock garden?

Gravel emerges as the superior ground cover choice for rock gardens due to its ability to complement the natural aesthetics of the setting. This environment typically favours smaller, more robust plants, including succulents and species adapted to thrive in nutrient-poor soils with minimal water. Gravel not only adds to the visual appeal of a rock garden but also facilitates drainage and minimises maintenance by suppressing weed growth, especially when used in conjunction with a landscape fabric. This makes it an ideal ground cover for creating a low-maintenance and beautiful surface layer.

What sand is best for rock garden?

For rock gardens, coarse builder's sand is the most practical choice, as it provides the optimal texture and drainage conditions for rock garden plants. The coarseness of the sand facilitates air and water movement, which is vital for the health of plants adapted to rocky environments. Conversely, fine-textured masonry sand compacts and retains moisture, which can hinder plant growth.

We have every type of gravel available to choose from in the UK. Check them out!

About the author 

Ben Parrot is a landscape gardener and amateur geologist. He is the founder of Outdoor Aggregates, with the mission to create the first encyclopaedia for decorative aggregates. From natural stone through to decorative bark, these aggregates are critical to garden and landscape design, universally.

The problem: There isn't any place where all the different types of decorative landscaping materials and construction aggregates can be found, nor are the specifications of each type readily available. So, enriched by his extensive experience, and inspired by the timeless elegance and raw beauty of stone and rock, etched by nature's artistry over millennia, Outdoor Aggregates was born.