In my May column, I discussed using a combination of drought-tolerant plants that would provide a sequence of colorful flowers in all seasons. Although there are drought-tolerant species which bloom every month of the year, a quick glance at the list of plants shows that there are many more Spring-blooming plants than plants that bloom during the other seasons. This phenomenon occurs because the natural habit of a drought-tolerant plant is to grow and bloom quickly after the winter rains. The blooms allow pollination to occur and the plants then set seed in order to assure their survival through the long dry season. Seeds are nature’s guarantee of continuation of the species and may lie dormant for many months or even years until enough rain falls to begin the cycle again.
But summer, fall and winter do not have to be drab months in the garden just because there are fewer flowers. On can design a beautiful and interesting garden just be using the many shades of green in juxtaposition to each other.
For many of us, grey foliage has a strong association with sunny climates. You have probably noticed by now that the foliage of drought-tolerant plants frequently has a grey cast. This can be due to either tiny hairs or a waxy white film on the leaf surfaces. The hairs allow the plant to capture moisture from the air while the waxy coating helps to prevent loss of moisture from the plant--both adaptions to drought. The resultant grey foliage further protects the plant by reflecting sunlight and heat away from the plant. Not surprisely, very few grey plants thrive in the shade.
All grey foliage helps to soften a landscape by acting as a buffer between harsher colors. It gives a restful quality to a garden and tends to make it seem lighter and airier. Since light colors appear to recede, grey also makes a garden seem larger, especially when it is used behind darker plantings. Greys are luminescent at night and ,when the moon is bright, allow you to see details of foliage that otherwise couldn’t be seen at night. Finally, grey foliage is a natural choice for integrating boulders, gravel and concrete into our gardens.
Among greys, there are at least three distinct hues:
Silver, or pure grey, stands out in the garden and can be used as an accent. The Artemesias, Senecios, Achillea “Moonshine”, Santolina, Convovulus cneorum and Cerastium tomentosum are familiar examples. All of these plants have very velvety leaf surfaces and most have white or pale yellow flowers. This coloration allows them to be pollinated by night-flying insects since they can be seen so easily!
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| Blue-grey foliage provides a very cool look, often welcome in full hot sun. The leaves look gorgeous when combined with blue and purple flowers. Acacia baileyana, Agave americana, and Festuca ovina ‘glauca’ ( glauca means blue in Latin nomenclature) all have very blue foliage.
Grey-green is probably the most common of the grey hues. Because so much of our native vegetation has this color foliage, this hue, used around the outside edges of the garden, is a blender and allows us to ‘borrow’ from the distant scenery. Grey-green is especially complemented by pink flowers. Examples are Stachys lanata (Lamb’s Ears), Lychnis, Pittosporum crassifolium ‘Nana’, Meterosideros excelsa (New Zealand Christmas Tree) and Echiu fastuosum (Pride of Madeira).
Rust or red foliage is less common among drought-tolerant plants, but the few representatives in this group make striking accents in the garden. Cordyline australis ‘atropurpurea’(Latin for dark red) is especially beautiful when combined with yellow-green foliage. Phormium tenax (New Zealand Flax) comes in many red and bronze varieties--’Atropurpureum’, ‘Bronze’ and ‘Rubrum’, for example. All are gorgeous in combination with Arizona flagstone, Saltillo tiles and even bricks. Photinia serrulata and Nandina domestica (Heavenly Bamboo) are both shrubs with reddish foliage which are quite drought-tolerant when established and will tolerate some shade.
Yellow-green or gold foliage is best used to light up dark areas but color conflicts with nearby flowers should be avoided. Use them as screens behind dark green foliage. Juniperus chinensis’Pfitzerana Aurea’ (gold in Latin, Coprosma repens “Variegata’, and Aucuba japonica ‘Variegata’(Gold Dust Plant) are all drought-tolerant plants with clear yellow markings.
Although many deep green plants are tropical and water-loving, there are some worth mentioining because of their drought-tolerance. This group of plants lends a shady glade-like quality to the garden. In fact, many of these plants are completely at home in the shade since, in their native habitats, they grow up under a dense foliage canopy. Pittosporun tobira and undulatun, Laurus nobilis(Bay Laurel), Myrtus communis, Acanthus molle and some of our own California natives such as Heteromoeles arbutifolia, Rhus integrifolia and Black Sage are examples.
By using a combination of all of these foliage colors, your garden can be filled with interesting and beautiful details even when it is not in bloom.