The Rock Garden, Part 3: Creative Ways to Use Texture

In this, the final post on the Rock Garden in Truro Nova Scotia, I want to look at one of the design features that make this type of garden so appealing: texture.

Generally, we turn to foliage, bark and other hard surfaces to add a textural element to a garden's design. In a rock garden, however, a low dense blanket of blooms can be used to create an exquisitely textured surface.

White Creeping Thyme, Thymus praecox 'Albiflorus'

Saxifraga paniculata 'Brevifolia'

Texture can be defined as the tactile quality of a surface. In contrast with the rugged, weather-beaten granite, there something jewel-like about the tiny green rosettes of this Saxifraga paniculata 'Brevifolia'.

Texture has a marvellous tactile quality. It is hard to resist touching soft, fuzzy foliage like this Pussy Toes, Antennaria dioica 'Rubra' (seen below).

Pink Pussy Toes, Antennaria dioica 'Rubra': is a native wildflower that has grey-green leaves and pink flowers in early summer. Pussy Toes are well suited to hot, sunny spots and poor, dry soil. Height: 10-12 cm (4-5 inches), Spread: 30-45 cm (12-18 inches) USDA Zones 3-9. 

So far most of my planting notes have featured alpines and perennials. In this post, I'd like to shift the focus briefly onto another key rock garden component: the conifers.

Darwin Carr, Operational Manager for the grounds at the Agricultural Campus of Dalhousie University notes:

"Dwarf conifers always look great when paired with alpines and rocks. They give the garden the look of high alpine terrain."

"Wind, ice and snow sculpt the native evergreen forest near the snow line of mountain tops into Krummholz, which is a German word meaning "crooked wood". Krummholz trees are usually short, attaining no more than six feet in height. These stunted, twisted trees are some of the inspiration for landscaping with dwarf conifers."

           

Picea abies 'Little Gem': is a Norway spruce cultivar that has a cushion-like habit.  This conifer is a slow grower (about 3" per year).  Full sun to light shade. Deer resistant. Needs regular watering especially during periods of summer heat. Height: 20-30 cm, Spread: 20-25 cm. USDA Zones 3-7.

Darwin Carr notes,"This is one of my favourite dwarf conifers. I have a nice one in a concrete trough at home that's been there for about 10 years. In that time, it has reached about the size of a dinner plate."

Carpeting the ground is Wooly thyme, Thymus pseudolanuginosus, in the left foreground is Cotoneaster adpressus 'Little Gem', directly behind the Cotoneaster is a Bristlecone Pine, Pinus artistata.

Too often people think a great garden is one that is filled with flowers but just look above to see how wonderful a scene that is primarily green can be. Contrast and texture make "green" interesting. The grey-green carpet of thyme is like soft velvet, whereas the Cotoneaster and Bristlecone Pine, by contrast, are stiff and spiky. 

Without the high drama of flowers, nothing demands your attention. There is a subtly at work here. I think that is why green feels so restful. It is like soft music.

The golden colored groundcover is Juniperus horizontalis. The weeping evergreen is Thuja canadensis 'Pendula'. The upright conifer is Juniperus chinensis 'Iowa'. 

When mixing together a scene that is generally green, you can add an extra level of sophistication by considering the directional flow of your foliage. 

In front of a group of upright conifers, this weeping evergreen Thuga canadensis 'Pendula' cascades in an incredible waterfall effect.

The plant with the silver foliage is Salix helvetica, the upright chartreuse shrub on the left is a dwarf Alberta spruce,  Picea glauca 'Rainbow's end' and the evergreen on the right is Picea abies 'Gregoryana Parsonii'.

Texture does not work its magic in isolation. Shape and color have a role to play in accentuating different textural surfaces.

This mix of plants includes is Phlox borealis ( magenta-mauve in color) and white Arabis x sturii and some small patches of white Candytuft, Iberis saxatilis.

And of course, in any rock garden, there is the stone. It is amazing to think that plants manage to grow in this spare, rocky landscape.

Spurless Columbine, Semiaquilegia 'Sugar Plum Fairy'

And yet they flourish and often in the most delicate way.

A cascading white Candytuft, Iberis saxatilis

Pinks, Dianthus 'La bourboule'

Sheriff's Rock Jasmine, Androsace sarmentosa 'Sherriffii': has mauve flowers and evergreen rosettes that form a trailing carpet. Excellent drainage is key to having success with this plant. Full sun or light shade (they may need a little afternoon shade in warm regions). Height: 10-12 cm (4-5 inches), Spread: 30-45 cm (12-18 inches) USDA Zones 3-9. 

Saxifraga paniculata 'Brevifolia'

Saxifraga paniculata: has rosettes of evergreen leaves and sprays of white flowers carried on maroon stems. This plant likes light shade and somewhat moist soil with good drainage. Height: 15-25 cm (6-10 inches), Spread: 25-30 cm (10-12 inches) USDA Zones 3-9. 

Red Lady's Fingers or Red Kidney Vetch, Anthyllis vulneraria var. 'Coccinea': has a low mound of silvery-green leaves and orange-red flowers in late spring. This plant tolerates poor soil and dry conditions once established. Full sun. Height: 15-20 cm (6-8 inches), Spread: 30-45 cm (12-18 inches) USDA Zones 4-9. 

Pasque flowers, Pulsatilla are unique in the many ways they manage to add texture. Not only are the grey-green leaves and bell-shaped flowers are soft and downy, but the seed heads are also as fine as baby's hair. The flowers bloom before the foliage emerges each spring and open in the morning sunshine and close each evening.

Darwin Carr tells me:

"We have an enormous number of Pulsatilla in the garden... We started with two species, and they really like growing conditions here, so if we don't deadhead them after flowering, we will have literally thousands of seedlings the next spring."

In the foreground is Japanese Burnet, Sanguisorba obtusa. In the middle ground are Pasque Flowers, that have gone to seed and in the upper left is Kashmir Mountain Ash, Sorbus cashmiriana which has white fruit.

I want to close this series by recommending that, if you ever are lucky enough to tour Nova Scotia, a visit to the Rock Garden on the Agricultural Campus of Dalhousie University is well worth your while. Already I am looking for any excuse to go back and see the other campus gardens that I missed the last time around: the Butterfly Garden, the Chef's Garden, the Alumni Garden and the Herb Garden.

But then, it doesn't take much of an excuse for me to want to visit my old home province of Nova Scotia. ( Missed the two earlier posts? Here's a link to Part 1 and Part 2.)