Plants Suitable for a Rock/Crevice Garden

Achillea oxyloba 

A type of a rock garden plant that has a carpet-growing/creeping habit. Grows best in humus-rich soil but will tolerate poor, gravely soil. Best grown under bright-filtered light/semi-shade conditions. Can be propagated by dividing the offsets.

photos courtesy of kadel.cz

Anemone x lesseri Wehrh.

Tuft-like in growth habit, the plant thrives in full sun, slightly rich, well-drained soil. It seeds in  winter and  grows  after 3 to 6 months.

Antirrhinum sempervirens

Known widely by the common name of 'snapdragons,' this decumbent-growing shrub is popular in crevice and rock gardens. Grown in full sun or light shade, it will grow best in well-drained soil but will adapt to poor soil. There are various species of the shrubs with different colored-blooms (pink, white, fuchsia).

Arnica cordifolia

The plant follows a tuft-like growing habit where it grows from a single base. The plant likes to grow in shady spots in the garden.  It thrives best in moist, humus-rich soil.

Aster souliei

A flowering, tuft plant, asters are very common in rock and crevice gardens. They grow abundantly in the alps, mostly in slightly humus-rich ground. Grown best in full sun. Flowers in the early summer to early fall.

Campanula bellidifolia

The plant thrives in the higher altitudes in the mountains in temperate zones. It blooms in late spring till summer.  Grows in dry, rocky terrain in full sun.

Coreopsis lanceolata

Grows in sunlit areas in very well-drained soil. Shows off golden-yellow blooms in  summertime. Leaves resemble spears (that explains the Latin suffix 'lanceolata').

Cistanthe tweedyi

This gorgeous plant grows from a rosette base (resembling a rose petal).  Flowers are pink and yellow observed at springtime. Thrives in sunny areas on crevices and rock gardens.

Dianthus haematocalyx

With purple-red flowers observed during summer, this cushion plant is excellent for covering up bare spaces in the garden but becomes a highlight in rock gardens. Propagated by seeds or through stem cuttings.

Alyssum daghestanicum

Alyssum is one of the favorites when it comes to the rock garden landscape. It is a very hardy plant and survives when grown in poor, rocky conditions just like its natural habitat up in the alpine mountains. It pops out from dry cracks in the rocks and blooms in spring. Stem cuttings are used to propagate this plant.

These are just a few of my favorites when it comes to rock garden plant ideas. Check with your local garden shops on what suitable plants to use in your particular hardiness zone.

Part 2: How to Create a Crevice Garden

Creating a crevice garden is not just throwing any kinds of rocks, pebbles, or gravel on where you want to establish your crevice garden--it is the art of setting up stones and filling in plants in a manner that it will resemble as if Mother Nature molded it herself. In the mountains of California and on peaks of the Canadian Rockies, one will notice plants growing from fissures in rocks from rocky terrains which are produced because of natural erosion.

You will need:

• rocks of various forms (flatter, round, rough, smooth, etc.) around 8 to 10cm thick and approximately 500 to 1000kg.
• gravel or pebbles (you can opt to choose one color throughout or spice it up with a different color tone) weighing 50kilos.
• rock garden/alpine plants
• a mound of soil or sand

NOTE: You can increase the number of rocks and soil if you want a bigger crevice garden.

Steps:

• Before doing anything, it is important to plan the outline of your future crevice garden. Pay attention to the location of the garden (sunny or shady), and have a rough idea of what plants you want to include and the overall look of the area.

Photo from WildGingerFarm

Photo from E. Drcar

• Cultivate the soil (and add in some sand if you want to pull off a desert look with cacti and succulents). A 3m by 3m measured crevice garden is ideal for someone who is just starting to master his skills in creating this kind of garden theme, or if he does not have enough space to make this garden. (For inspiration, you can get crevice gardening ideas by checking crevice garden images online).

• Layout the bigger rocks on the ground first. Do it in such a method that it looks like a gently sloping hill. Position it at least twenty degrees to assist with drainage of water from the top to bottom. The other side must be a lot steeper. Start placing the rocks and work your way from the top going down. Position the rocks at least 5cm apart. Border the bottom stones against the top rocks to reinforce the foundation (rearrange the rocks until it looks natural and you are contented with its appearance).

• On the more steep side, bury the rocks in the mound as if you are forming a ledge. Tilt it inwards while following the same angle (20 degrees) as on the other side. Dig about 2/3 deep when burying the rocks.
• Add soil to fill in the cracks or crevices. Start planting with your chosen plants. Cover it with mulch (fine gravel or tulfa depending on your preference) to put everything together.

Part 1:What is Crevice Gardening?

Phlox subulata 'Creeping Phlox'

Nobody would want to be stuck between a 'rock and a hard place.' But the opposite happens when it comes to nature. I am amazed at how certain plants adapt to such harsh growing conditions (rocky, sandy soil, drought) and still flourish.

Crevice gardens are naturally formed on the alpine regions where there is little or sans fertile soil available; drier surroundings, and lesser oxygen supply...plants survive adversity, grow up to be healthy and give off a glorious display of foliage and blooms. It's as if these plants just popped up from the cracks or crevices created by a pile of rocks! Many mountain trekkers who have seen the savage yet alluring contrast between stones and flowers, have decided to create a garden of their own resembling that of the natural display of plants growing in a 'sea of rocks.'

The stark contrast between delicate, pretty blooms and the rugged, rough gravel and rocks make crevice garden a masterpiece of its own (I guess those nooks and crannies in the garden are useful after all).

Calluna vulgaris 'Heather' growing between rocks.

These photos were taken when I was walking along the neighborhood in Fairfield, Victoria. The flowers are so beautiful to ignore that I had to stop and greet them with my camera. I happened to come across a house with a crevice garden so I took a picture of it. The garden was just occupying a small area on the front yard.