Evergreen Trees Drop Leaves Too

IMG_20141004_153228As the deciduous trees that will soon be coloring for autumn defoliate for winter, the evergreen trees will become more prominent. Some evergreen trees will drop some of their foliage along with deciduous trees through autumn and winter. Many drop some of their old foliage as new foliage develops in spring, or later in summer. All are on distinct schedules, but are never completely bare.

That certainly does not mean that evergreen trees are not messy. To the contrary, some happen to be significantly messier than some deciduous trees are. They are only evergreen because they do not drop their old foliage until it is replaced by new foliage. Whether individual leaves last just slightly longer than a single year, or for several years, they eventually shed and fall to the ground.

In fact, evergreen trees may shed small but pestering volumes of foliage for a few months or even constantly throughout the year. Some deciduous trees defoliate so efficiently within a very limited time once the weather gets cool, that all of their fallen leaves will be raked away within only two or three weeks. Of course, some trees, both deciduous and evergreen, drop flowers or fruit or both.

Not only do most evergreen trees shed for a longer time than most deciduous trees do, but most shed foliage that is not so easy to rake away. Cypress shed minute and finely textured leaves that are impossible to rake from lawns, but toxic if they accumulate. Juniper and arborvitae are easier to accommodate only because the trees are smaller. Fir, spruce and cedar have bigger needles.

Broadleaf evergreen trees are very different from coniferous trees. Their leaves are considerably easier to rake. They are generally more substantial than those of deciduous trees though. Some may not decompose so readily in deep groundcover. Southern magnolia leaves are notably slow to compost. Instead of producing cones, some broadleaf trees drop acorns or other messy seed.

Nonetheless, where there are compatible with their landscapes, evergreen trees are as practical as deciduous trees are.

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Leyland Cypress

91113The ‘X’ preceding its Latin name ‘X Cupressocyparis leylanii‘ designates Leyland cypress as a hybrid of two distinct genera, namely Monterey cypress and Nootka cypress. (Those who consider the parents to be two species of the same genus know Leyland cypress as Cupressus X leylandii.) The many cultivars combine desirable qualities of both parents, but also innate weaknesses.

Rows of Leyland cypress grow fast to become densely evergreen windbreaks or informal screens within only a few years. However, they are very susceptible to cypress canker, and are likely to succumb within twenty five years or so. Farther inland, they may not last half as long. That may be quite acceptable for temporary windbreaks in front of slower but more permanent shrubby trees.

Common Leyland cypress develops a distinctly plump but conical form, with slightly grayish foliage. Most other cultivars are more columnar. Foliar color ranges from bluish green to gold. The tiny scale leaves are densely set in flat sprays. Healthy trees can get nearly thirty feet tall in ten years. Most stay lower where exposed. Crowded trees that live long enough exceed a hundred feet tall.

Weeping White Spruce

41029As the colorful deciduous trees go bare, the evergreen trees get more attention. A weeping white spruce, Picea glauca ‘Pendula’, really stands out. It grows slowly to only about fifteen feet tall and maybe five feet wide, so does not need as much space as a typical spruce tree. What makes it so distinctive is the weirdly pendulous stems that hang limply from a strictly vertical trunk. It is hard to believe that it is only a different variety of the same species as the dwarf Alberta spruce, which is very short, dense and symmetrically conical, with stout little stems. The foliage of weeping white spruce is lighter green than that of most other spruces, but is not as blue as that of blue spruce. The short and stiff needles are rather prickly to handle.

The narrow and weirdly sculptural form of the weeping white spruce is no good as a shade tree, but is an excellent trophy tree for a prominent spot. Full sun is best. A bit of shade can cause the main trunk to lean toward sunlight. Young trees should only be staked if they need it, since they can become dependent on stakes. The lowest limbs can be allowed to creep over the ground.

Oriental Spruce

60127If it got as big as it does in the wild, Oriental spruce, Picea orientalis, would not fit into many home gardens. It can get more than a hundred feet tall! Fortunately, it does not often get much more than twenty five feet tall locally. Trees that compete with taller trees in forested landscapes might get to forty feet tall. Their symmetrically conical canopies get about fifteen or twenty feet broad.

The tiny needles of Oriental spruce are less than half an inch long, so are smaller than those of any other spruce. Relative to the finely textured deep green foliage, the densely arranged and neatly angular stems are notably stout. Like other spruces, Oriental spruce is best where it has sufficient space to retain lower stems down to the ground. It can look rather silly with a bare lower trunk.

Garden varieties are more common and stay smaller than the straight species. ‘Skylands’ has yellow foliage, although it fades in warm situations. ‘Aurea’ has paler pastel yellow new foliage that matures to green. ‘Gowdy’ has a narrow columnar form, and grows very slowly. ‘Nana’ develops as a plump low mound that stays less than three feet tall. All like to be watered somewhat regularly.

Conifers Have A Woodsy Style

81205Conifers are the most prominent forest trees in North America, but are notably scarce in home gardens. Except for compact varieties of juniper (which were probably too common years ago) and arborvitae, most conifers are trees that get too big for residential gardens, and few adapt to regular pruning that might keep them contained. Almost all are evergreen, so block sunlight in winter.

Gingko (maidenhair tree), bald cypress and dawn redwood happen to be deciduous conifers; but gingko is typically thought of as a ‘broadleaf’ (not coniferous) tree, and bald cypress and dawn redwood are quite rare. The various podocarpuses are useful coniferous trees that happen to be very complaisant to pruning, but like gingko, they are typically thought of as broadleaf trees.

Junipers and arborvitaes are just as practical for home gardens as they ever were, and the many modern varieties that have been introduces over the years are even more interesting than the old classics. Modern arborvitaes are more compact. Modern junipers exhibit more colorful foliage, and more distinctive forms and textures. Foliage can be lemony yellow or blue like a blue spruce.

Simply speaking, conifers are cone bearing plants. They are typically outfitted with needle or scale leaves. Of course, it is not that simple. Juniper seeds are contained in fleshy structures that resemble berries. Gingo and podocarpus seeds actually come with a squishy mess. So, ‘cones’ are not always as easy to recognize as pine cones are. Neither are the wide ‘needles’ of gingko.

Redwoods, pines, cedars, cypresses, Leyland cypresses, spruces and firs are the more familiar of the larger coniferous trees. Bunya bunya, Norfolk Island pine, western red cedar, incense cedar and the various yews and chamaecyparises are somewhat rare. Larch and hemlock are very rare because they do not like the climate here. With few exceptions, these larger conifers have dominant central trunks that can not be pruned down without ruining the structure of the trees as they develop.80516

‘Red Star’ Atlantic Whitecedar

60106Is it red or white? Actually, it is neither. ‘Whitecedar’ is the common name for Chamaecyparis thyoides, which is a formidable coastal conifer from Maine to Mississippi. ‘Red Star’ is a much smaller garden variety. Its finely textured foliage is bluish green when it first emerges in spring, and can turn slightly purplish or bronzed gray if it gets cold enough in winter, but never turns red.

In more humid climates, ‘Red Star’ Atlantic whitecedar can eventually reach second story eaves, and can get half as broad. It rarely gets half as large locally, and can take quite a few years to do so. The slightly aromatic evergreen growth is densely conical, almost like a lumpy dwarf Alberta Spruce with an upwardly rounded underside. It can be a bit more sculptural if partially shaded.

Even without pruning, ‘Red Star’ Atlantic whitecedar is symmetrical enough for formal landscapes. Alternatively, it can add a bit of formality to relaxed landscapes. Although it is slow to provide privacy, it works nicely as an unshorn hedge. If somewhat crowded in a row, it grows taller faster. Shorn hedges lack natural form, but can recover their natural texture between shearing.

Living Christmas Trees Grow Up

81031All around town, there are Italian stone pines, Canary Island pines, Monterey pines and Aleppo pines that are much too big for the home gardens that they live in. Some are too close to pavement or foundations. Others are under utility cables. Many are shading or crowding out other more desirable plants. What most have in common is that they started out as living Christmas trees.

Because they seem to be so cute and innocent when they are decorated in a small pot, living Christmas trees very often get planted where they really do not belong. Not much consideration is given to their true potential. Pines are innately difficult to contain, and can not easily be pruned back for confinement once they get growing in a space that is not spacious enough for them.

Living Christmas trees simply are not often the horticulturally responsible option for Christmas trees that we would like to believe that they are. Very few end up in good situations where they have room to grow. Planting them in the wild is not practical, since their roots are too confined to survive without watering. Because they are not native, they should not be planted in the wild anyway.

Contrary to popular belief, the most popular of the living Christmas trees do not do well in containers long enough to function as Christmas trees for more than just a few years. Some spruces and small pines can be happy in containers for many years, but can be demanding. If their roots get too disfigured, they are less likely to adapt to the landscape when they outgrow containment.

Ironically, cut Christmas trees are usually more practical than living Christmas trees. They may seem to be expensive, but they are less expensive than living Christmas trees of good quality (unless a living Christmas tree functions for a few years.) Even though they are bigger, cut Christmas trees are not as heavy and unwieldy as the big tubs of soil needed to sustain living trees.

Cut Christmas trees are not harvested from forests, but are grown on farms like any other horticultural commodity. There should be no guilt associated with bringing one into the home. In the end, they can be composted or otherwise recycled like green-waste. There is no long term commitment, and no need to provide accommodations for an eventually humongous tree in the garden.

Those who insist on procuring a living Christmas tree should choose responsibly, and be ready to accommodate a growing young tree. Although not big enough to be real Christmas trees, dwarf Alberta spruce like those in the picture above are sometimes decorated as a small live Christmas tree. They happen to be conducive to confinement in proportionate pots. One in the ground, they grow like strictly conical shrubs that do not get big enough to cause problems.

Deodar Cedar

81205Some of us may remember deodar cedar, Cedrus deodara, from the opening scene of the Andy Griffith Show. They were in the background as Andy Taylor and his son Opie skipped stones on Myers Lake near Mayberry in North Carolina. Those well established and naturalized trees and the pond are actually in Franklin Canyon Park in the Santa Monica Mountains above Beverly Hills.

If only it did not get big enough to shade most of a compact home garden, deodar cedar would be better than most other evergreen coniferous trees used in California landscapes. It enjoys the warmth and sunshine here, and does not require any more water than what most regions that are not desert get from rain. It eventually gets fifty feet tall and thirty feet wide, and might get bigger.

The glaucous grayish needle leaves are about an inch or two long, and are arranged either in tight terminal clusters on the tips of short and stout stems, or singly on longer and pendulous shoots. Ideally, trees develop conical canopies with horizontal limbs that droop at the tips. Some trees develop a few main trunks down low, or big structurally deficient limbs that curve irregularly upward.

Dwarf Alberta Spruce

81031It is so tempting to dress up a densely conical dwarf Alberta spruce, Picea glauca ‘Conica’, as a garden gnome for Halloween. They are so symmetrical that they seem to have been shorn that way. They are too small to be classified as trees, but are not as shrubby as most shrubbery either. Their practicality is rather limited to formal situations where their strict symmetry is desirable.

Dwarf Alberta spruce is very different from the straight (not dwarf) species that can get to almost fifty feet tall. It instead grows very slowly, and stays quite small, although it can eventually reach downstairs eaves. The finely textured evergreen foliage is soft but slightly bristly. The tiny individual needles are only about half an inch long. The aroma of crushed foliage might be objectionable.

Dwarf Alberta spruce is popularly grown as a potted Christmas tree, and happens to be one of the few coniferous plants that can stay potted long enough to functions as such for a few years. In the ground, it wants rich but well drained soil. It can rot if the soil stays too damp. Red spider mite can be a potential problem. Although it likes full sun exposure, it can get roasted in hot situations.

Dawn Redwood

70816If it has bark like a coastal redwood, and foliage like a coastal redwood, and a slender conical structure like a coastal redwood, it is most likely a coastal redwood. If it turns orangish brown in autumn and defoliates through winter, it is the much less common dawn redwood, Metasequoia glyptostroboides. It is one of only a few distinctive genera of coniferous trees that are deciduous.

Upon closer inspection, it is not as similar to coastal redwood as it initially appears. Besides being deciduous, the foliage of dawn redwood is softer and lighter grassy green. Individual leaves are more perpendicular to the stems. Trunks are more tapered, so that they are quite lean up high, and quite plump down low. Old trees can form buttressed trunks. Strips of bark might exfoliate.

Dawn redwood is by no means a deciduous alternative to the evergreen coastal redwood. Although it grows about as fast while young, it slows with maturity. Crowded trees get taller but lanky. Exposed trees stay shorter and broader, but because they are still relatively narrowly conical, they do not make much shade at first. Old trees are more than a hundred feet tall, but could get taller.