Gardening : New Zealand Shrub Feels at Home
Arriving at nurseries right about now are the many varieties of one of Southern California’s best shrubs, the leptospermums, also known as New Zealand tea trees, because the leaves were apparently used to prevent scurvy on sailing ships a long way from home.
Though they grow almost like native plants here, they originally came from those islands, where they are known as manukas. They are fast-growing, drought resistant, pest-free and flower in winter and early spring.
Though some never seem to stop flowering (but this has to do with pruning), they generally begin in the late fall and peak now. March is their month, when they finally come into full, fat flower, which is why nurseries stock up on leptospermums at this time of the year.
This is definitely the only way to buy them--in full flower--because the names are much confused and the colors distinct enough to require seeing in person before any decision is made. In flower you can see that those called “pink” are quite rosy, and usually not a clear pink, and that the reds are ruby-like or burgundy and nothing like a fire engine.
Like most plants from the Southern Hemisphere, their colors are a bit different than those of us on this half of the globe are accustomed to, and they don’t always blend harmoniously without a little effort on the planter’s part.
The double-white varieties are certainly safe in any color scheme, and are probably the prettiest of all since they look remarkably like fruit tree blossoms. The best known of the hybrid leptospermums is the one named ‘Ruby Glow,’ which has deep ruby-red or oxblood blossoms that are also double. They look all the more handsome because the slender, sliver-like leaves are also tinged with red. This was one of the first to be introduced by pioneer plant breeder Walter E. Lammerts, who hybridized a number of leptospermums while at UCLA in the 1940s.
(A remarkable man, he also hybridized eastern lilacs (‘Lavender lady’) for Descanso Gardens; California lilacs, or ceanothus (‘Sierra Blue’); peach trees (the ‘Daily News’ series), plus a number of roses and camellias.)
In New Zealand and Australia there are many kinds of leptospermums and quite a few have found their way to our shores, but the best known, including ‘Ruby Glow,’ are hybrids of Leptospermum scoparium . These are the ones with the prettiest flowers, and they fall into roughly two groups.
There are those with reddish foliage and dark-red flowers. ‘Ruby Glow’ is one of these. Others include ‘Red Damask,’ ‘Winter Cheer’ and ‘Crimson Glory,’ which along with ‘Ruby Queen’ grow to about 10 feet, though they can be kept around 6 feet with pruning. Two other red-flowered, red-foliaged cultivars get a few feet taller--’Burgundy Queen’ and ‘Atlantis,’ which has perhaps the reddest foliage.
The other group grows taller, to 12 feet given the opportunity. These have green foliage and include ‘Blossom’ with blush-pink double flowers; ‘Pink Pearl,’ with its pink buds and white double flowers; ‘Martinii’ with single white and rose flowers; ‘Helene Strybing’ with single, deep-pink flowers, and ‘Sunyasia’ a rose pink with large flowers.
‘Fascination,’ a double pink, is the shortest of this lot, growing to only 8 or 10 feet, though there is one named ‘Nanum Tui’ that supposedly grows to only 3 feet, though New Zealand books put it at closer to 6.
The shortest is probably ‘Pink Cascade,’ a low, spreading variant that would make a fine bank cover, growing about 2 feet tall by 10 feet wide, but most of the common leptospermums are big shrubs. Even with regular pruning it is difficult to keep them under a window at 6 feet tall, and it is not too hard to spot examples of leptospermums that their owners are having a hard time keeping in bounds.
Because they flower profusely when only a foot tall, and because their branches and leaves are so light and airy, many gardeners must assume that what they’ve bought is going to be a small shrub. But, figure 10 feet tall, and as big around, for most. A few will even assume small tree proportions in time.
This is no reason not to plant them, just give them room to grow. They are particularly attractive against the walls of a house, which shows off their delicate structure, but don’t put them in front of windows or too close to doors.
They are also handsome in front of taller, dark-green shrubs with larger leaves, and in front of dark fences. They are not much of a screen since they are not dense.
In most gardens, they should be pruned every year after flowering. Pruning helps slow them down and it encourages a second round of flowers (which is why some appear to bloom all year).
The flowers come on new growth, so if you cut them back, they immediately make new growth and then flower a few months later.
Don’t prune with a hedge shear, however. Prune by taking out entire branches back to a secondary branch, thereby removing enough growth to make the plant smaller without destroying its natural grace.
As an example, find one branch, follow it down past two or three side branches and then make your cut just above another side branch that faces up or out from the plant. Do this to each branch until the desired effect is achieved.
The flowering branches, incidentally, are excellent cut, lasting several days in a vase.
Other than pruning, there is little to do. Leptospermums can take being watered along with everything else, or they can be left to fend for themselves, with only an occasional irrigation inland where the summers get really hot.
The best time to plant is in the fall, or right away, so the plants are established by summer. Even then, they will need frequent watering the first summer since they do not have their roots deep in the soil yet.
They do like a location with full sun. They are not fussy about soil, and require no special soil preparation, and no fertilizer in most situations.
They just grow happily (and rapidly) and flower. And, in the middle of winter and in early spring, those flowers are a delight.
