I was wandering around my local garden centre the other day and saw the most amazing display of that exquisite American shrub, Kalmia latifolia, with a wide range of varieties on display in full flower. This is one of those shrubs that has never attained the degree of popularity it deserves, and if you are looking for a small to medium sized evergreen shrub which flowers in early summer you could not do better than this wonderful species.
Commonly called Mountain Laurel in its native country, it is a member of the vast Ericaceous tribe. It is found from Maine down to northern Florida and extends westwards as far as Indiana and Louisiana.
Unsurprisingly for a member of the same family as heaths and rhododendrons, it is usually found on soils with a very low pH – about 4.5 to 5.5. is the norm – and like rhododendrons, is toxic to most stock. Some related species are known as “sheep kill” so it gives you a good idea of the danger of planting this beauty along a fence line on a farm! You might also want to avoid major plantings if you are a hay fever sufferer, as the pollen is said to be a bad irritant, although it flowers as the same time as so many grasses that I do not think you would notice it unless you popped your nose into the flowers.
In the wild Kalmias have rounded clusters of beautiful light pink to white flowers, each dotted with a little “stitch” where the stamen have been pushing against the inside of the petals – it is sometimes called the Calico Bush. Even the buds are very attractive, crimped and pointed like little buttons of icing on top of a sweet cake.
To be grown very well the Kalmia needs to be placed in well-drained but moisture retentive soil, preferably with low pH. It can cope with light shade but it is equally happy at home in full sun. As it flowers late in the season the flowers are not usually prone to frost damage and it can be relied on for a glorious flowering season.
About ten years ago I was determined to grow one here although our soil conditions are not really ideal. I found a fairly sheltered spot and dug bag after bag of compost into the soil before purchasing a well-grown specimen from a Rotorua nursery. It has flourished and each year at this time I marvel at how well it has done, and how much it flourishes.
But when I see the great range of colours available now, I feel cheated, and I have to say I am scanning around the garden to see where I could make some room for a new shrub or two of these beauties.
Among the varieties that took my eye the other day, ‘Carousel’ was probably the pick. This is an American bred cultivar, from the extensive planned crosses by the doyen of Kalmia breeders Richard Jaynes. It has light pink buds, and flowers that are light pink but dominated by the bands of cinnamon red. The effect is off a brightly banded bouquet of flowers. It is relatively slow growing and should not be more than 1.5 metres high and across by the end of ten years.
I was also taken with the brightly flowered ‘Minuet’, a smaller growing variety with large flowers. The light pink buds open to dark pink flowers with a light pink centre and bands of bright cinnamon red. This variety, which is smaller growing as the name indicates, also bears unique, dark green narrow leaves. This is another of Richard Jaynes’ varieties.
‘Yankee Doddle’ is another stunning type. The buds of this cultivar are bright red-pink and they open to show a pink corolla with a narrow maroon band, giving the effect of a strawberry parfait. Despite its very American sounding name, this cultivar was actually bred in Germany, where Kalmias are very popular garden plants.