Rock Garden Plants For Low Maintenance

Last Updated on May 7, 2021 by Grow with Bovees

When building your rock garden, you should consider what types of plants you will be planting in it. We have some tips for plants that are easy to look after.

As with any kind of gardening, your choice of plants will depend on the local climate as well as on the size and position of your rockery.

Some of the easiest plants to grow are the various kinds of succulents, which need very little care.

Cacti also make decorative and easy-to-grow drought tolerant plants for a low-maintenance rockery.

Succulents are ideal plants for the rockery, for they thrive in conditions where drainage is good and usually grow in full sun amongst stones in nature.

Crassulas are particularly attractive as they generally have showy flowers.

Here again, the rampant growers like C. multicava, which spread so easily in the shade, must be weeded out periodically, but it can be controlled easily.

Beautiful species like C. falcata and C. portulacea, however, do not spread very much and are ideal where conditions are suitable.

The American Sedums (Stonecrops) are ideal for planting amongst rocks and the dwarf species will grow in poor soil, but must be kept in check constantly.

Aloes are perfect succulents for the rockery, for they grow amongst rocks in nature and there are scores from which to make a choice.

Cacti make striking plants in a rock garden, but do not blend well with ordinary garden flowers and should be planted almost as an architectural feature to complement the house.

They are mainly of interest for their grotesque forms, not for their flowering habits, and are of special interest to collectors.

Succulents and Cacti For Rock Gardens

NameHeightColor

Aeonium arboreum
1m – 39″Yellow
Aloe sp.10cm to 2m – 4″ to 6ftRed, orange, yellow
Bulbine sp.25cm – 10″Yellow
Cotyledon sp.20cm to 2m – 8″ to 6ftVarious
Crassula sp.30cm to 1m – 12″ to 3ftPink, red
Drosanthemum sp.10cm to 60cm – 4″ to 24″Pink, purple, red
Echeveria sp.15cm to 30cm – 6″ to 12″Red, yellow, orange
Euphorbia sp.5cm to 2m – 2″ to 6ftVarious
Kalanchoe sp.30cm to 1m – 12″ to 3ftVarious
Lampranthus sp.15cm to 30cm – 6″ to 18″Various
Mesembryanthemum crystallinum8cm – 3″White
Rochea coccinea (red crassula)60cm – 24″Red
Sedum sp. (stone crop)15cm to 40cm – 6″ to 16″Yellow, white
Sempervivum sp.15cm to 30cm – 6″ to 12″Purple, carmine, yellow

If you live in an area which has heavy rain and is not so suited to the growing of cacti and succulents, you could make a conifer rock garden. There is a wide range of small conifers in very attractive shapes and colors to choose from and, once established, they need very little care.

Small shrubs are also a good choice -there are many varieties of old favorites that are compact-growing and these are ideal for a rockery.

Compact bedding plants, such as dwarf marigolds and dwarf ageratum, will add color to your rock garden.

Small Shrubs For The Rockery

Shrubs are very suitable and it is amazing how many small shrubs can be found to dress the rock garden.

Use as many evergreens as possible, for they prevent a bare look in winter.

Plants like Heath and Strelitzia are extremely successful. Shrubs which drape themselves over rocks, like Purple Lantana or Flame Pea (Chorizema) are delightful.

It is advisable to plant several tall shrubs or small trees in the larger rockery in order to give it an interesting form.

Choose trees that do not spread too much and cover the rocks unless you have an extremely large rockery.

Small trees with slim trunks and a fairly narrow habit, such as Dais cotinifolia, Weeping Bottlebrush, Cussonia paniculata (Cabbage Tree) and Tamarisk are best.

Shrubs with a suckering habit like Kerria japonica (Globe Flower) and Rhus lyphina should not be planted, for they behave like rampant perennials.

NameHeightColor
Barleria reptans60cm – 24″Red
Cotoneaster dammeri ‘Lowfast’30cm – 12″White, red berries
Cuphea hyssopifolia30cm – 12″Purple, white
Erica sp.30cm to 2m – 12″ to 6ftVarious
Hebe sp. (veronica)45cm to 1.25m – 18″ to 4ftVarious
Juniperus horizontalis ‘Wiltonii’30cm – 12″Blue-gray foliage
Lantana montevidensis60cm – 24″Mauve
Leucospermum sp.’ (pincushion)75cm to 2m – 30″ to 6ftRed, yellow, orange
Protea sp.1m to 5m – 3ft to 16ftVarious
Reinwardtia indica (yellow flax)1m – 3ftYellow
Thuja occidentalis ‘Rheingold’60cm – 24″Orange foliage

Suitable For A Well Drained Rockery

Other popular plants for a rockery are the many different kinds of ericas, which also need well-drained, slightly acid soil. For growing most other plants, the soil should be a mixture of garden loam and compost, much the same as the soil you would use when growing these plants in your garden beds.

The most important thing to remember when choosing plants for a rock garden is to get plants that all need the same growing conditions, as this will make caring for them so much easier. The depth of soil in most rockeries is fairly limited, so it is best to choose plants with shallow root systems.

Avoid plants that grow very vigorously — these usually have large, invasive root systems and will quickly overgrow the rockery and choke out smaller plants.

Rock Garden Plants For Shade

If your rock garden is in a shady area of your yard, you can still plant it with many plants suited to shade.

While the majority of the more popular rockery plants (such as ericas and succulents) need a sunny position, there are many other shade-loving plants that can easily be grown in a rock garden.

The varieties you choose will depend on local conditions, the size of your rockery, and the depth of the planting pockets.
If yours is a sizable rockery, you could grow large ferns such as;

  • Blechnum sp.
  • Tree ferns
  • Elephants ear
  • Shade loving species of Cycads
  • Plectranthus
  • Philodendron sp.
  • Acanthus mollis.

Rock Garden Plants For Deep Soil Pockets

Plants For A Small Rockery

  • Various Ferns
  • Hens and chicks (Chlorophytum comosum)
  • Small-growing fuchsias
  • Dwarf azaleas
  • Hellebores
  • Shade loving groundcovers

Suited To Full Sun

Geraniums are a good choice for a rockery situated in full sun.

Perennial Plants For The Rock Garden

Perennials such as Barberton daisies, Agapanthus and Red Hot Pokers are very suitable for rock gardens, not only because their spread can be checked, but because their appearance suits the rocky setting.

Creeping perennials like Wild Strawberry (Duchesnea), Cerastium (Snow-in-Summer), Santa Barbara Daisy (Erigeron karvinskianus), Pelargoniums and Mesembryanthemum are also suitable, but must be kept in check carefully.

Try to confine each of them to one spot and do not allow them to spread beyond their allotted area. Weed them out ruthlessly if they begin to smother nearby plants.

NameSizeColor
Arctotis sp.25cm to 35cm – 10″ to 14″Orange, yellow
Convolvulus mauritanicus (ground morning glory)20cm – 8″Violet
Diascia integerrima (twin spur)30cm – 12″Red-pink
Erigeron macranthus25cm – 10″White
Felicia amelloides (blue daisy)45cm – 18″Blue
Gazania sp.10cm to 15cm – 4″ to 6″Various
Geranium incanum (carpet geranium)15cm – 6″Mauve
Gerbera jamesonii (Barberton daisy)60cm – 24″Various
Limonium sp. (statice)60cm – 24″Lavender, white
Nepeta mussinii (catmint)20cm – 8″Lavender
Osteospermum sp. (trailing daisy)20cm to 50cm – 8″ to 18″White, blue
Pelargonium sp. (geranium)15cm to 70cm – 6″ to 28″Various
Scabiosa caucasica (scabious)75cm – 30″Mauve

Bulbs For The Rock Garden

Bulbs such as Yellow Arums, Pineapple Flowers (Eucomis), Tulbaghia fragrans, Daffodils, Ranunculus, Anemones and many others are suitable as they do not spread too freely and can be lifted easily when dormant.

NameHeightColor
Anemone coronaria30cm – 12″Various
Babiana stricta (wine cup)20cm – 8″Purple
Clivia miniata45cm to 75cm – 18″ to 30″Orange
Freesia hybrids40 cm – 16″Various
Nerine sp.45cm – 18″Pink, red
Ranunculus asiaticus30cm – 12″Various
Tritonia crocata45cm – 18″Orange

Annual Plants For The Rockery

Almost any annual can be planted in the rockery, but the best ones are of the type that create a massed display of color, like Namaqualand daisies, rather than the type that sends up a slender stem, even though the flower itself is beautiful, like Clarkia or Godetia.

The massed bushy flowers fill the rock pockets gracefully and overflow the edges of the rocks in a natural manner.

Stiff, spiky annuals may look rather prim and out of place. On the other hand, some common annuals like the taller Petunias are too spreading in growth and should be avoided, particularly in a small rockery.

The ideal annual for the rockery should be fairly compact and not sprawl untidily like Echium Blue Bedder.

Low-growing annuals, like Ageralum and Dorotkeanthus, are particularly valuable for the front of the rockery.

Be careful of annuals like Marigolds that seed themselves so freely that they overrun everything. They must be scrupulously weeded out in the following season.

One should plant the type of annual which is used more for display than as a cut flower, so that one is not tempted to cut the blooms for the vase.

Members of the daisy family are particularly suitable.

NameHeightColor
Ageratum houstonianum hybrids (floss flower)20cm – 8″Blue, pink, white
Arctotis hybrids30cm – 12″Red, orange, yellow
Dimorphotheca sinuata (Namaqualand daisy)30cm – 12″Various
Dorotheanthus bellidiformis10cm – 4″Various
Eschscholzia California (Californian poppy)45cm – 18″Various
Felicia bergerana (kingfisher daisy)15cm – 6″Blue
Linaria maroccana45cm – 18″Various
Lobelia erinus15cm – 6″Blue, pink, white
Lobularia maritima (alyssum)15cm – 6″”White, mauve, pink
Nemesia strumosa hybrids30cm – 12″Rose pink
Petunia hybrids30cm – 12″Various
Tagetes patula hybrids (dwarf marigold)15cm to 25cm – 6″ to 10″Yellow, orange, brown
Tropaeolum majus (nasturtium)30cm – 12″Various
Ursinia sp.30cm – 12″Yellow, orange
Verbena hybrids20cm – 8″Various

Climbers

Climbers are valuable in a large rockery.

Bougainvillea or Canary Creeper (Senecio tamoides) can be very attractive spreading over stones and slopes.

How To Plant The Rock Garden

Having decided on the plants to use, one must try to avoid a spotty effect by planting one of everything irrespective of its size.

Group several plants of one kind in each pocket as a start.

One pocket can be filled with dozens of one type of annual such as Nemesia, and another filled with two or three small shrubs of a kind, like Strelitzia or Cape Heath.

Larger plants like Pride-of-Madeira (Echium fastuosum) can be represented by single specimens.

Even though the pocket is filled mainly with one type of plant, other plants can be placed at the corners of the pockets to avoid a too formal look and appear as if they overflow from one bed to the next.

Barberton daisies (Gerbera) or Bergenia are particularly suitable as they love the cool root run under the rocks, while their pretty foliage softens the stone without hiding it completely.

Most of the decorative rock surfaces should continue to show when the plants are fully grown, for if they are completely overgrown, the character of the rock garden will be lost.

You should put in as many permanent plants as possible and arrange a few beds of annuals here and there for a brilliant show.

Quick-growing annuals, like Phlox, can also be used to dress the rockery until the slower, more permanent shrubs have grown.

It is better to rely on the display of annuals at first than to over plant with specimens of a permanent character.

In general, the larger plants should be planted at the back of the rockery, that is, in the top pockets, while dwarf plants should be planted in the lower pockets, so that they can be seen easily.

In some portions, however, bring taller plants to the fore or the planting will become monotonous.

Maintenance of the Rockery

The well-built rockery requires very little maintenance, but weeds and grass should not be allowed to gain a foothold in the rocks.

Do not allow the lawn to grow right up to the rocks in the front as it will be very difficult to mow and require a great deal of hand labor to keep it from growing up into the crevices of the rocks.

The lawn should be trimmed with an edging tool to make a neat edge following the curve of the rockery at least one foot away from the rocks.

This narrow bed can be filled with many small plants which look good against the rocks and help to link the rockery to the rest of the garden.

Water the rock garden regularly and allow the spray to soak well down into the soil. You may find it necessary to water the rockery only about twice a week if this is done thoroughly.

Rock gardens devoted to succulents need be watered less frequently, particularly when they are accustomed to having a dry period in nature. This will depend on whether they come from a summer or winter-rainfall area.

Snails are fond of making their home in the damp areas under the rocks and must be kept in check before they can damage small plants. Use snail bait early in spring to prevent these pests from multiplying.

Do not allow trailing shrubs like Lantana montevidensis or shrubby perennials like certain Bush Salvias to become straggly.

They may be cut back after flowering or during winter and will make neat growth in the spring.

In all cases keep the rockery neat and check the spread of the same type of plant everywhere.

A small pocket of wild strawberry is delightful, but it soon becomes a pest if it is allowed to creep into every part of the rockery.

FAQ

Non-flowering Geraniums

Q. The geraniums in our rockery are all making a great deal of leaf growth but hardly any flowers. What could be the reason?

A. Geraniums and pelargoniums usually grow extremely well in a rockery, but they can fail to flower for a number of reasons. To bloom successfully, they must be in full sun, and they do best in light, fertile, free draining soil.

If the soil in your rockery is very rich – perhaps with too much compost in it – the plants will make lush leaf growth at the expense of flowers.

Over-watering geraniums, especially if the soil is poorly drained, can encourage the production of too many leaves. Over-feeding the plants with a high-nitrogen fertilizer could also result in too much leaf growth.

On the other hand, if the geraniums make flower buds that fail to open, they may have been stung by a type of fly whose developing maggots destroy the buds. If this is the case, spray the plants with carbaryl as soon as the buds appear.

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