PERENNIAL FAVOURITES
Some work better here than others
Now that the long-awaited halcyon days of summer are upon us, it’s time to sit back, put your feet up and ease into relax mode in the garden, right? To a degree, yes. But now is the perfect time to review what has worked, what has not and why? The plant material that has disappointed should probably be removed and replaced with an alternate.
Perennials, the backbone of most gardens, will be either thriving now or performing rather poorly. If the latter is the case, determine the cause. Is the perennial in the right location — meaning is it in full shade when it should be in full sun and vice versa? Have the watering requirements been met? Leaves will turn pale and take on a yellow hue if the plant has been overwatered.
If it’s a flowering perennial, are the flowers robust and numerous or sickly and sparse? If it’s the latter, the plant is not receiving enough nutrients. Applications of Rage Plus should fix this problem.
Many perennials are on sale at garden centres and big box stores, so consider removing the poor performing perennials and replace them with something else. This short list of perennials work well in our Zone 4a (we have gone up a notch from Zone 3):
Anemone or windflower. This spring-flowering perennial prefers a slightly shaded spot and does best in woodland and rock gardens.
■ Artemisia or silvermound. Inconspicuous flowers on silver foliage. Thrives in full sun with little attention. Does not like wet soil. Can become invasive if not kept in check.
■ Bee Balm. As the name implies, it is a magnet for bees and hummingbirds. Adaptable from full sun to full shade, although the latter increases the likelihood of powdery mildew. Its lemonscented leaves can be used to brew tea.
■ Campanula or bellflower. A workhorse and must-have perennial as it is a prolific bloomer thriving in full sun, partial shade or light shade. If you cut the bellflower back by one-third after it has flowered, with luck, you will enjoy a second late-season flush. Not to be confused with Creeping Campanula — the tall, spike-like weed with purple/ blue flowers. The bane of many a gardener, Creeping bellflower produces up to 15,000 seeds per plant.
■ Blazing Star or Gayfeather. Tall, spiky, fuzzy flowers that will bloom until fall. Makes an ideal cut flower and prefers full sun. Does well in planters and is deer resistant. It is the safe replacement for the banned purple loosestrife — sometimes referred to as the beautiful killer.
■ Columbine. This old-fashioned perennial will self-seed, but is not considered invasive. It resents having its roots disturbed. Its “babies” rarely resemble the parent plant as it cross-breeds easily.
■ Cranesbill or Hardy Geranium. Another workhorse that should be a staple in the border. A prolific grower and bloomer with few pests or diseases to worry about. Partial to light shade is ideal.
■ Delphinium. One of my personal favourites, this English garden-inspired beauty does well in full sun protected from strong winds as the stalk is actually hollow and snaps easily. Susceptible, however, to the delphinium moth caterpillar — a nasty “worm” that will cause leaf deformities and small flowers. Eradicate this pest as soon as it becomes evident by either cutting the plant to its base (in the fall), applying a biological insecticide or pick off the caterpillars. The plant, as is the case with Monkshood and other members of the larkspur family, is toxic if ingested.
■ Foxglove or Digitalis. Another English-garden favourite, this perennial will happily re-seed if planted in the right soil and location. Ideal conditions are partial to light shade in an acidic, moist, fertile soil. Deadheading will produce a second flush. Oddly enough, even though the plant is poisonous, the heart medication digitalis is made from the plant’s extracts.
■ Peony. I’ve saved the best for last. There can be nothing more heavenly than a peony in full bloom. It prefers full sun but will tolerate partial shade. Planting depth is key, however, as peonies will not bloom if planted too deep nor too shallow. The buds — or eyes on the tuber — should be 2.5 to 5 centimetres below the soil surface. It resents being moved and may sulk for years. It does not like composted manure. Makes an ideal cut flower and is beautifully scented. Ants — always prevalent on peonies it seems — can be washed off after cutting.
The above represents but a smattering of perennials that grow well in Calgary gardens. For a more diverse list, pick up the book Perennials for Alberta by Donna Dawson and Laura Peters (Lone Pine).