Besides the rains finally subsiding (almost), there are some sure signs that summer has finally arrived: a sudden run on Corona beer and limes; the smell of barbeques permeating the early evening air; and the re-emergence of kayaks and canoes on the roof racks of weekend warriors.
Another, more subtle sign of the warmer weather is the arrival of summer heathers at your local garden centre.
There are three species of summer heather that I would like to touch on, with two of them being widely available and the third worth looking for.
The first of these, Erica cinerea, is a native of Europe, Zone 6 hardy and much resembles the winter-flowering species (Erica carnea or x darleyensis) with its fine needled foliage.
It also features a broad colour range from white (‘Alba’), to shell pink (‘Pink Ice’), right up to an eye-catching magenta (‘Atrosanguinea’).
Erica cinerea forms a typical rounded or mounding shrub and is well-suited to mass planting, where individual plants can grow together as a tall groundcover and provide a much greater visual impact when in bloom.
There are several gold-leaved cultivars available, including ‘Golden Sport’, with its amber foliage and rose-pink flowers, as well as ‘Celebration’, which features unnatural-looking, but attractive electric yellow needles contrasted by pure white blooms.
Two other good varieties to keep an eye out for include ‘P.S. Patrick’ (purple) and ‘C.D. Eason’ (magenta-pink).
Erica cinerea has a blooming period that ranges from late June to September, depending on the variety.
Calluna vulgaris, or Scotch heather, is another worthy shrub that often gets overlooked because of its upright, almost spiky growth. This unfortunate ‘snub at first glance’ robs many of us of one of the more hardy heathers (Zone 5) that also provides long seasons of both foliar and flower colour.
Although summer blooming, their appeal begins in early spring when the new growth of many cultivars such as ‘Red Fred’, ‘Spring Torch’, ‘Leslie Slinger’, ‘Moon Glow’ and ‘Flamingo’ show their cream, yellow, pink or red tips – making for a display that rivals its blooming season.
When in flower, the abundant double white flowers of ‘Kinlochruel’ make it one of the better choices for an Alba garden, while the intensely metallic foliage of
‘Silver Knight’ is a year-round focal point.
This species also includes the ‘bud bloomers’, or varieties whose flowers do not open and, because of this, retain their colour for months on end, often lasting through to January.
Finally, as the regular flowering season fades and frosts make an appearance, many of the gold-leaved cultivars (such as ‘Firefly’ and ‘Hoyerhagen’) shift to a dramatic reddish-orange for the balance of winter.
As mentioned earlier, the upright habit and coarse scale-like needles of Calluna vulgaris make it an excellent foil for the predominantly green mounds (when not in bloom) of Erica.
My last summer heather prospect is Irish heath, or Daboecia cantabrica – which can be a bit hard to find. It features dark green foliage composed of tiny leaves with an erect growth habit, often reaching heights of 45 centimetres.
The bell-shaped flowers are fewer in number, but about three times larger than most heather, and they sit well above the foliage on airy spikes.
The real clincher here is the long blooming season, as many varieties of Irish heath steadily flower from July to October.
‘Rainbow’ is a variegated form with irregular streaks of gold in the foliage and contrasting purple blooms.
Some other locally available cultivars include ‘Alba’ (white), ‘Arielle’ (magenta), ‘Vanessa’ (purple) and ‘Waley’s Red.’
In general, summer heathers are best used in foreground groupings of three to five plants, although larger mass displays can be appropriate, depending on the scale of the garden.
They also combine well with small conifers such as Thuja ‘Rheingold’, dwarf balsam fir (Abies balsamea ‘Nana’), ‘Blue Star’ juniper and Chamaecyparis ‘Heatherbun’.
Perennials are another good companion plant, although you will have to be careful not to crowd the heather, as they brown out rather easily when covered by neighbouring foliage.
A long season of bloom is preferred here, so a few good choices would be Leucanthemum ‘Broadway Lights’, Coreopsis ‘Zagreb’, Hemerocallis ‘Stella D’Oro’, Phygelius ‘Purple Prince’ or Rudbeckia ‘Goldsturm’.
As far as growing conditions are concerned – all summer heathers prefer part (at least five hours) to full sun, acidic soil and good drainage – as Phytophthora or root rot can be a problem in wet areas.
Mike Lascelle is a local nursery manager and gardening author. Email him at firstname.lastname@example.org. Visit his blog at www.soulofagardener.wordpress.com to read two new stories: The Two-Headed Plant Freak and Blogging … The New Petroglyphs.