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.

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.

California Bay

70823Just because California bay, Umbellularia californica, can be used like Grecian or sweet bay for culinary purposes does not necessarily mean that it should be. California bay has a stronger and much more pungent flavor and aroma. Some might suggest substituting less than half California bay for Grecian bay. However, even if the intensity is adjusted accordingly, the flavor might be off.

As the name suggests, California bay is native to California. However, because it is from rainier climates, it prefers a slight bit more water than it would get naturally in the drier parts of the local chaparral climate. It provides nice cooling shade in large landscapes, but is a bit too dark and messy for refined home gardens. The aromatic leaf litter can annoy delicate annuals and seedlings.

Well exposed trees can eventually get more than thirty feet tall and almost as broad. Forest trees that compete with other trees can get a hundred feet tall! Small trees can be shorn as hedges. If not watered too generously, the roots tend to be rather complaisant. However, old trees can eventually develop massively distended burl growths known as lignotubers at the bases of their trunks.

How Shade Is Made

70816thumbMany of our trees live at our homes longer than we do. Some of our trees were there before we got there. Some of the trees we plant will be there for whomever comes along after we are gone. Trees very often evolve into something very different from what they were intended to be. Nonetheless, since they are the most significant features of our gardens, trees must be selected carefully.

The recommendation that shade trees near the home should be deciduous is cliché but accurate. It makes sense that the trees that provide cooling shade in summer will also allow warmth and light through while bare in the winter. Evergreen trees are better for obscuring undesirable views around the perimeter of the garden, where they will not shade the home too much through winter.

The problem is that many modern gardens are too small for such diversity. Modern homes are so close to each other that evergreen trees are more important for obscuring views. Consequently, evergreen trees that provide privacy between homes and gardens might also function as shade trees. Limited space also means that trees affect neighboring homes and gardens significantly.

This is why so many of the small trees (that are known almost disdainfully by some arborists as ‘microtrees’) are so popular. Japanese maple, flowering cherry and smoke tree that were once popular for atriums and small enclosed gardens are now popular shade trees. Realistically though, some modern backyards are not much bigger than what was once considered to be an atrium.

Small evergreen trees or large shrubbery, like Australian willow, mayten, photinia and the larger pittosporums, work nicely by providing both privacy and shade for small areas. Contrary to popular belief though, evergreens are generally messier than deciduous trees. They drop small amounts of foliage throughout the year instead of dropping most or all of their foliage within a limited season. Flowers or fruit add another dimension of mess, even for deciduous trees like crape myrtle, flowering crabapple and saucer magnolia.