Ottawa Horticultural Society

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A Lot Going For Them (Shrubs)

Shrubs are not new to our concept of landscaping, but what a long way we have come since the only shrub gracing many farm homes was the syringa vulgaris or common lilac, still a feature of many areas where rural homes once accented the environment! Or spirea Van Houttei which long characterized the country school or church yard! But advances in hybridization, modern transportation and countless nursery catalogues have combined to present a grave selection of problems for the inexperienced homemaker. Often nurseries stock items not suited to local conditions, and though many catalogues provide hardiness data for trees and shrubs, customers still tempt fate by disregarding advice, ordering exotic plants suited to southern Ontario or the Pacific coast. They end up discouraged at loss of time and money.

There is no firm list of five, ten or any number of "best" shrubs, since conditions and requirements vary widely. The first questions a customer should address to himself are "What need do I wish to fill? Do I want a large, small or medium plant? Shall I emphasize bloom, coloured foliage, fruit for birds? Am I prepared to prune regularly and carefully, or must my shrub fend for itself" What I hope to do is to establish, by process of elimination, a list of 5 shrubs, each combining as many features as possible, with little attention required but high hopes for a measure of success.

To accomplish this, I must omit many excellent varieties. Few may agree with my views, but I offer my choice for those who wonder how to start selecting. If you choose for bloom alone, you may covet prunus glandulosa (flowering almond) or Weigela Bristol Ruby, but bear in mind many of the showiest varieties have a brief bloom span-sometimes 3 or 4 days. Others such as magnolia, althea (rose of Sharon), kerria and buddleia are just not reliably hardy in our area. Still others like kolkwitzia (beauty bush), weigela and chaenomeles (quince) will not winter kill but will lose much top growth to the winter elements, requiring heavy pruning each spring, often resulting in scant bloom production. Most forsythia and rose tree of China (prunus multiplex) seem winter hardy, but bloom production may be irregular, often scarce or confined to branches protected by deep snow.

If you live in an area where field mice or rabbits are a menace, their hors d' oeuvres are euonymus alata and members of the prunus, malus, chaenomeles and cotoneaster families, as well as some dwarf juniper. Plastic collars protect young single-trunk trees but I have had to cut a 6-Ioot euonymus alata down to 4 inches after mice had whetted their winter appetites on bark and sap. Snowball (viburnum opulus sterile) misses my preferred list purely because of susceptibility to aphid attacks, though these are easily controlled with any good systematic spray.

A few, notably symphoricarpos (snowberry) and spirea billardi do not make my honour roll because of a tendency to spread from suckers or underground stolons. However, if you wish colour when bleak fall arrives and most deciduous foliage has dropped, snowberry may be your answer.

1978 was the greatest snowberry crop ever! If it's late bloom you want, try hamamelis virginiana (common witch hazel) whose yellow blooms are to October or early November what the forsythia is to early May. If you would beat the bunch to the punch with early spring colour, choose salix caprea (French pussy willow) or daphne mezereum, covered in lavender in April, before the foliage. If your fancy turns to foliage colours other than green, try maroon prunus cistena (purple-leaved sandcherry). In gold, a "biggie" is the sambucus aureus (golden elder) but 4 feet gives you philadelphus coronarius aureus (golden mock orange). If your choice is variegated, one of the best is dogwood, cornus alba sibirica elegantissima in green and white. Euonymus alata or dwarfer alata compacta shows gorgeous fall colour. Winter contrast is provided with red or yellow-barked dogwood against a snow background, or add a dwarf Koster blue spruce or golden cyparis. Honeysuckle (Ionicera) yields a tremendous harvest of bird food in July, branches dropping to the ground with its crop of red berries. Various virburnums show clusters of fruit in all stages of ripening from

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white and light green, through red to blue black, while cotoneaster acutifolia has good-sized tart black fruit. The pink seed pods of some euonymus split to reveal bright red pips kite-flying on pink wings. To say nothing of rose hips and a multitude of flowering crabapple varieties. If you are an arranger needing shrub branches with a natural trend to decorative use, try fantail or corkscrew willow or the twisted twigs of corylus avellana contorta (corkscrew hazel or lauder's walking stick).

What criteria must my top notchers fit? I must have both large and small to fit whatever situation arises. I need reliable hardiness to avoid periodic replacement. I want an enduring show of bloom or recurrent bloom over a long period, preferably providing colour in mid-summer when spring perennials have passed but annuals have not yet come into production. They must be relatively free of disease and reasonably immune to insect and rodent depredation.

As large shrubs, I nominate syringa (lilac) and philadelphus (mock orange). Both grow 8 to 12 feet, though there are dwarfer ones. Both are clean and healthy, requiring only selective pruning. Their perfume makes your garden an Eden. Every garden of any size should have a lilac. For gorgeous bloom I prefer the French hybrids but for healthier, neater plants, with a heavier bloom crop, try the Prestoniae hybrids originated by the late Isabella Preston of the Central Experimental Farm. James McFarlane, a good pink, Nocturne in blue, purple Royalty and wine-red Redwine add colour variety in June well after the French hybrids. My favourite mock orange is philadelphus virginale, thanks to the purity of its semi-double white blooms emitting heavenly fragrance, late June to early July.

Lower-growing, fitting into almost any niche, I choose potentilla as my favourite small shrub. Dainty lacy foliage on gracefully arching branches, blooming from late June right into fall, it always shows colour and seldom becomes shabby. I prefer Goldfinger's larger blooms and richer colour, but I grow several other yellows, also white Abbotswood and the so-called orange Tangerine (orange only under ideal conditions, otherwise yellow). I have not tried newer Red Ace or peach-pink Daydawn, but regardless of colour, potentillas have a lot going for them. They may be attacked by mice if the winter population is high and other delicacies are not available.

There are scads of spirea varieties, from early white garland strains, through Van Houttei white cluster types, to the summer-flowering rose-red heads such as old Anthony Waterer. These latter are pruned in spring, small weak stems removed to the ground, stronger one cut back ½ to 2/3 their length, to improve bloom size and produce compact, strong growth. Of these, spirea arguta Goldflame gets my nod as No. 2 best Iow-growing shrub. It emerges in beautiful golden new growth, greening as summer advances and producing an abundance of rose-red blooms. If these are removed and cut back when dead, another crop will follow. The foliage becomes a beautiful crimson in fall, in prime condition on the plant till November freeze-up. Like the hydrangea, no real harm is done if mice prune a little early, since spring pruning improves growth and flower production, unlike spring bloomers which fail to flower if the old wood is cut back before bloom time.

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