When the sun is hot and there’s little time for watering, it’s a big time-saver to have drought-resistant plants in the garden – and if you know what to look for, the plants themselves will tell you how they conserve water.
Some plants, like cosmos, resist drought because their leaves are very finely-cut threads which give virtually no moisture back into the atmosphere.
The annual cosmos – some grow to two metres (six feet) tall, and others to just 20 centimetres (eight inches) – make a delicate cloud of green studded with large, usually pink or white flowers.
Another annual with filigree leaves is the blue, white, or pink-flowered nigella (Love in a Mist).
Then there’s the perennial Coreopsis verticillata which makes a fluffy-looking leafy mat of yellow daisies that slowly expands over the years.
At the other extreme are plants that store water in their leaves. Cactus can store large amounts, but in our south-west B.C. climate, you’re far more likely to run across sempervivums (Hen and Chickens). They grow in thick rosettes that shoulder out weeds. Colours vary from red to green, or combinations. Sempervivum archnoidium is covered with white cobweb-like threads. All are very hardy, perennial, and drought-resistant. An older rosette may throw up a scaly stemmed, small but exotic-looking flower cluster. The rosette then dies, but younger rosettes soon fill the gap.
The annual portulaca also stores water in succulent leaves, which are said to be edible (like the vegetable purslane). Portulaca loves poor, dry soil. Baby portulacas need water, but they soon grow out of it, and go on to produce bright, little rose-like flowers despite our long summer droughts.
Needle-like leaves, like those of rosemary and pine, are another sign of drought-resistance.
Other plants have lacy leaves, like yarrow, or narrow leaves, like ornamental grasses and the perennial Armeria (Thrift).
Stachys lanata (Lambs Ears) has wooly grey leaves. The greyness reflects light and the fine hairs trap moisture.
Other plants’ waxy surfaces reduce water loss. Acanthus has a thick surface skin; others, like carnations and pinks, have thinner skin, but still effective.
Some plants resist drought thanks to long, thick taproots. Oriental poppies fall into this group. Another group has fat tubers that store enough nutriments to give them a second start after hard times – bearded irises are among them.
Bulbs usually need water during their growing season, but later, many go dormant, a habit developed to escape long, dry summers in their native homes.
Tulips, for instance, need a dry dormancy to keep them healthy. Hardy cyclamen corms and allium bulbs prefer dry summers, too.
Virtually all drought-resistant plants are sun-lovers. That’s why water-saving is so large on their agenda.
News flash: There will be a self-guided garden tour of eight Maple Ridge gardens, 9 a.m. – 4 p.m. Sunday, June 22. Brochures are $20 on sale at three nurseries: Triple Tree, Amsterdam, and Grow and Gather. The tour ranges from a small urban garden to a rhododendron paradise.