Larch

41217Climate is why the European larch, Larix decidua, is so rare here. It prefers cooler weather in both winter and summer, and more humidity. Foliage can roast if too exposed through summer. Small trees that are partly sheltered or partly shaded by larger trees have the best color and foliar density. Larch are innately reliant on somewhat regular watering, so are not drought tolerant. The mildly cool weather of autumn is enough to brown the formerly bluish foliage, which falls shortly afterward.

In the wild, larch trees can get as tall as other big coniferous trees. However, the many different garden varieties stay much smaller. Some are very pendulous. A few have contorted stems. Of the few that can sometimes be seen locally, most are compact dwarfs that grow more like low and dense shrubbery than trees. Some get only two or three feet tall and broad, and grow very slowly. These can stay in containers or planters for many years.

Not All Evergreens Are Conifers

41217thumb‘Conifer’ and ‘evergreen’ are almost synonymous. Of the two, ‘evergreen’ is the more familiar term. Some people do not know what a ‘conifer’ is. Simply speaking, an evergreen is a plant that retains foliage throughout the year, even while deciduous plants defoliate through winter. A conifer is a plant that produces seeds in cones, such as pine cones, although many are not easy to recognize as such. Actually though, not all evergreens are conifers; and not all conifers are evergreens.

Southern magnolia, glossy privet, lily of the Nile, all sorts of eucalyptus and all sorts of palms retain their foliage through winter, but none are conifers. Larch, dawn redwood and bald cypress are conifers, but are also deciduous. This can be quite a surprise for anyone expecting them to be evergreen. The foliage turns brown enough to resemble death before defoliation, although larch can get quite colorful in autumn where winters are cooler.

Now that flowers for cutting are scarce, evergreen foliage is popularly cut and brought into the home instead. Here in California, not many of us have fir or spruce out in the garden. Redwood, pine, cypress and cedar (deodar and Atlas) are more common. Leyland cypress, Western red cedar, incense cedar and the various chamaecyparis are not as common, but are just as effective. Incense cedar as well as some of the junipers (unshorn) are particularly aromatic.

Since the various hollies are uncommon here, Californians prefer other evergreens with berries, such as firethorn (pyracantha), contoneaster and toyon. Incidentally, toyon had been so recognized as a substitute for holly that it had historically been known as California holly, and is the origin of the name of Hollywood. Magnolia grenades (fruiting structures) can function like weird pine cones. Southern magnolia has big and glossy leaves with rusty orange undersides. They can provide bold color and texture, even if they have dried to a rich brown.

There are of course no rules for cut foliage. Anything that is still foliated and appealing in the garden may work nicely in the home. Ferns are an obvious choice, although some drop spores that stain fabric. Various pittosporums, podocarpus, eucalyptus, New Zealand flax and even the leaves of bird of paradise are all worth a try.

Spruced Up

P91214KSpruce happen to very compatible with the landscape style here. They fit in nicely with surrounding redwoods, but are more proportionate to sunny spots of some of the refined landscapes. We intend to add a few into some of the landscapes as they get renovated. They will stay branched to the ground, like big dense shrubbery, with the personality of distinguished forest trees.

Several dwarf Alberta spruce, which is a very compact cultivar of white spruce, have been incorporated into landscapes that were renovated during the past few years. They really are dinky though, and stay smaller than most shrubbery. Some of the very compact cultivars of blue spruce that we would like to add next will eventually get significantly bigger, but do not grow fast.

A few spruce that grow more like tree rather than shrubbery would be really excellent. The taller blue spruce with more open branch structure are no longer available from local nurseries, but could be ordered. I particularly want to try any of the white, black, red, Engelmann or Sitka spruce that are endemic to North America, although I know some might not be happy here.

Sitka spruce just happened to become available. A colleague brought these eight seedlings back from the coast up near the Oregon border, and will probably get a few more. They are prolific there, and get pulled like many other weeds. At the rate they are growing, they could get planted into a landscape even before we get any blue spruce! I am already very pleased with them.

For a while, I grew each of the six North American spruce, but only in cans. Since these Sitka spruce arrived, I have been wanting to get the other five. White spruce is ‘sort of’ here. Blue spruce will arrive soon enough.

Deciduous Evergreens

P91201Well, that is certainly a contradiction of terms. One might say it is an oxymoron. Decades ago, it really was how we classified what we now know more simply as ‘deciduous conifers’. There are not many of them. Ginkgo is a gymnosperm like conifers are, but is not really a conifer. Otherwise, there are only five other types of deciduous conifers, which defoliate through winter.

Laryx is a genus of about a dozen species that are known collectively as larch. Taxodium includes two species known as bald cypress, as well as a third evergreen species. Pseudolaryx amabilis, known as golden larch, Glyptostrobus pensilis, known as Chinese swamp cypress, and Metasequoia glyptostroboides, known as dawn redwood, are all three monospecific genera.

Some species of larch are common within their respective natural ranges. So are the bald cypresses. The others are quite rare. However, dawn redwood became a fad decades ago, so is not so rare in landscape situations. To those of us who expect all conifers to be evergreen, deciduous conifers seem to die suddenly in autumn. To some, it is not exactly a desirable characteristic.

The dawn redwood above lives in our landscapes. The tall evergreen trees behind it are native coastal redwood. Obscured by the yellowing birch to the right, a small giant redwood (another oxymoron) represents the third and only other species of redwood. The fall color of this dawn redwood appeals to some, but to others, it looks like one of the native redwoods abruptly died.

Our bald cypress below does not look so much like a dead redwood. The foliar texture and branch structure are quite distinct. The cinnamon brown fall color is actually rather appealing.

Of course, these pictures are nearly two weeks old. By now, both trees are likely bare because of the rain.P91201+

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.

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.