Evergreens Make A Mess Too

Big evergreen trees make big messes.

Nature is messy. It is that simple. Leaves, flowers, fruits and stems regularly fall from vegetation onto the ground. Animals contribute their mess too. Insects and microorganisms seem to eliminate most of the mess. In reality, they merely accelerate the process of recycling the mess back into more mess. Decomposing organic matter sustains viable vegetation as it perpetuates the process.

Natural mess serves many other purposes as well. It really is an important component of ecology. It retains moisture and insulates the soil. Many plants drop foliage that inhibits the germination of competing plants. Many merely smother competing plants with their mess. Several, particularly locally, produce combustible debris to incinerate their competition in the next convenient forest fire!

Obviously, the sort of mess that is so beneficial in nature is not so desirable in home gardens. Even if weed suppression and moisture retention are appealing, combustibility is not! Neither is any mess that vegetation deposits onto hardscapes, roofs or lawns. Such mess becomes more apparent as deciduous trees defoliate this time of year. Most produced no other mess since last year.

As messy as deciduous trees are, they are generally no messier than evergreen trees. They just happen to defoliate within a very limited season, rather than throughout the year. Some evergreen trees shed more in a particular season, typically as new foliage replaces the old. Otherwise, they shed slowly and persistently throughout the year. The mess seems like less, but is just prolonged.

Both evergreen and deciduous trees serve their respective purposes. Evergreen trees obscure unwanted scenery all year. Deciduous trees provide cooling shade for summer, and allow warming sunlight through for winter. The misconception that deciduous trees are necessarily messier should not exclude them from home gardens. Deciduous trees are often the most appropriate options.

Every species and cultivar of tree is unique. Many deciduous trees actually are messier than some evergreen trees. However, most are not.

Dormancy And Defoliation Are Advantageous

Kahili ginger is finished blooming, and should get cut back once the foliage succumbs to frost.

Many plants are deciduous in autumn and winter, which means that they defoliate or die back, and then refoliate or regenerate in spring. Many others are evergreen, which simply means that they are always foliated through all seasons. What many people do not realize is that evergreen plants replace their foliage just like deciduous plants do. They just do not do it in such distinct phases of defoliation, dormancy and refoliation.

Tropical plants like cannas and some of the various begonias really have no need for formal defoliation, since they are from climates that lack winter. In the wild, they continually and systematically shed old stems as they produce new stems. Locally, they tend to shed more than they grow during late autumn and winter. The large types of begonias tend to keep their canes for so many years that it is not so obvious. Where winters are colder, cannas freeze to the ground, only to regenerate from their thick rhizomes as winter ends.

Zonal geraniums may seem rather tired this time of year for the opposite reason. They expect late autumn weather to include frost that would kill them back to the ground where they would stay relatively dormant until warmer weather after winter. Just because their foliage is instead evergreen through winter does not mean that it should be. It lingers and often becomes infested with mildew and rust (fungal diseases) that proliferate in humid autumn weather.

However, zonal geraniums need not be pruned back just yet. Even if they eventually get damaged by frost, pruning should be delayed so that the already damaged older foliage and stems can shelter the even more sensitive new growth as it emerges below. They can get cut back after frost would be likely.

Evergreen pear can get very spotty once the warm weather runs out because the same damp and cool weather that inhibits its growth also promotes proliferation of the blight that damages and discolors the foliage. The damaged foliage eventually gets replaced as new foliage emerges in spring, but will remain spotty and discolored until then. Photinia does not get as spotty, but holds blighted foliage longer into the following summer. Ivy can be temporarily damaged by a visually similar blight.

Dividing Perennials Equates To Multiplying

Yuccas can get divided after bloom.

This seems like bad algebra. Horticulturally, dividing and multiplying really are the same. Division is the separation of crowded perennials into smaller but more numerous portions. It multiplies the number of individual plants. The smaller portions perform better than they did while crowded. Division is both a method of vegetative (clonal) propagation, and a form of healthy social distancing.

Many perennials are ready for dividing about now. They finished blooming through spring or summer, and are going dormant for winter. Some defoliate. Division is not so disruptive to them while they rest. Cool and damp weather keeps them hydrated. They can disperse roots and resume growth as winter ends, as if nothing ever happened. They should bloom right on schedule next year.

The most popular perennials grow for many years before getting overgrown enough to benefit from division. Some may technically never need dividing. They manage to perform adequately even as dense thicket growth. For some, division is primarily for propagation. Only a few perennials appreciate annual division. Perennials that bloom in autumn or winter prefer division in early spring.

Pigsqueak will bloom later in winter. Dividing it now with other perennials would inhibit and retard the blooming process. It will be ready for dividing before winter ends, so can settle in with the last winter and spring rain. The same applies to Japanese anemone, which might still be blooming now. Dividing these two perennials is typically for propagation or containment, rather than crowding.

Lily of the Nile and African iris do not need dividing often, but when they do, it can be a major chore. For moderate crowding, it is relatively easy to pluck many individual shoots without disturbing remaining shoots. However, it is typically more practical to dig bulky colonies, divide them into individual shoots, and then plant the shoots. African iris shoots work best in groups of five to twelve.

Lily of the Nile, with dividing earlier than later, disperses roots in winter, to bloom for summer.

Dried Flowers Last All Year

These flowers were cut weeks ago, and will look just as fresh months later.

Statice, strawflower and globe thistle continue to bloom later than most other summer annuals, and hold their flowers longer. Even after bloom, the flowers are so stiff and ‘crispy’ that they remain intact and colorful until they succumb to exposure to weather. If cut and brought in from the weather soon enough, they will last as dried flowers at least until fresh flowers start to bloom in the garden next spring.

Strawflower and larger globe thistle tend to wilt and droop from the weight of the bulky flowers, so should be tied in small bunches and hung upside down to dry. Perennial statice (which has larger blooms than annual statice) tends to flop to the ground, but the stems often bend only at the base so that the rest of the stem length stays somewhat straight. Smaller globe thistle and annual statice often dry standing up while still out in the garden.

Yarrow and English lavender can be dried as well, but lose most of their color. Lavender dries naturally in the garden. Yarrow can likewise be allowed to dry in the garden, but probably keeps a bit more color if cut while still fresh and hung upside down. Because yarrow blooms are so wide, they should be hung individually or in small bundles. Queen Anne’s lace has even wider blooms that curl inward as they dry, so they really should be hung individually.

Old hydrangea flowers that are only beginning to fade can dry surprisingly well if cut and hung individually before they deteriorate too much or start to rot. Some varieties retain color better than others. Some fade almost completely to an appealing brown paper bag.

There are not many roses this time of year, but when they do bloom, even they can be cut and dried while beginning to unfurl. Only a few small and tightly budded roses can be dried when completely open. Because they droop right below the blooms, roses should be hung upside down to dry. Dark colored roses get very dark as they dry. White roses turn tan. Pink and yellow are probably the better colors.

Cat-tails and pampas grass flowers are big, bold and dated cut flowers. Yet, for situations where big flowers fit, they are just as practical now as they were in the 1970s. Because pampas grass flowers shed, and cat-tails can explode (to disperse their seed), they should be sprayed with hair spray or another fixative to keep them contained. Pampas grass foliage has dangerously serrate edges that can give nasty paper cuts, so should be handled carefully, and displayed out of the way.

Tree Surgeons Evolved Into Arborists

Tree surgeons maintain the big trees.

Arborists are very specialized horticulturists. They prefer to work with trees. Of course that is not as simple as it sounds. Some are nurserymen who grow trees. Some select appropriate trees for landscape design. Even some of the orchardists who work with many trees of a similar type have earned this prestigious designation. Decades ago, we still knew many of them as tree surgeons.

Arboriculture, which is the specialized horticulture of trees, has certainly evolved through the decades. Tree surgeons no longer graft fruit trees directly in home gardens. Nurserymen graft trees in production nurseries, to make them available from retail nurseries. However, modern tree surgeons now work with much more diversity of many species that were unknown to their predecessors.

As storms become more frequent through autumn and winter, the need for arboriculture becomes more apparent. More unstable trees fall. More structural deficient limbs break. Many trees prefer to be pruned while dormant through winter. In actuality though, arboriculture is important throughout the year. Some procedures, for some sorts of trees, should happen significantly earlier or later.

Trees are the most substantial features of home gardens. Once they grow beyond reach, they need to be maintained by qualified tree surgeons. Regardless of what most say, very few gardeners are qualified to perform major arboricultural procedures. Many tree surgeons will attest to finding that most damage that trees endure is caused by gardeners with minimal regard for arboriculture.

Tree surgeons who are Certified Arborists of the International Society of Arboriculture, or ‘ISA’, have demonstrated their proficiency with arboriculture. After passing their certification examination, Certified Arborists maintain their credentials by continued involvement with educational seminars, classes and workshops of the ISA. Not many other horticultural professionals are so dedicated.

More information about procuring the services of an ISA certified arborist can be found at www.isa-arbor.com.

Many Perennials Want Seasonal Grooming

Peacock orchid bloom late, but eventually succumbs to frost and must be groomed.

Here on the west coast, autumn and winter weather is so mild that the native coral bells are already starting to develop new foliage on top of the old foliage from this last year. Technically, they are evergreen, so the old foliage does not need to be shed; but if it is not too much to ask, some types look better with a bit of grooming.

Other perennial plants that are from climates with stronger seasons and colder winters are not quite so evergreen. Many shed all of their foliage and are completely bare for at least part of the winter. Only a few, like cyclamen, are at their best through autumn and winter.

Dried watsonia foliage should be removed now if it has not been removed already. It is not so easy to pluck off like gladiola foliage is, so it should be cut off with shears. Because new foliage for next year develops before the old foliage of this past year is completely brown, it is often necessary to cut the old a few inches above the ground in order to avoid damaging the new.

The so called ‘evergreen’ daylilies can be even messier. New foliage is rather delicate, so it is easily tattered by the removal of old foliage. The ‘deciduous’ types may seem to be less appealing because they are bare for part of autumn and winter, but are so much easier to groom by simply removing all of the deteriorating old foliage as soon as it separates easily from the roots.

Deteriorating flowers can be removed from cannas; but their lush foliage can stay until it starts to deteriorate later in winter. Even if it survives winter, it should eventually be cut to the ground as it gets replaced by new growth in spring.

The many different iris have many different personalities. Most should be groomed sometime between summer and late autumn, although Dutch iris were groomed much earlier. Bearded iris that do not get divided can be groomed simply by plucking off big old leaves to expose smaller new shoots below.

Some dahlias bloom until they get frosted. Most though, are already finished. They do not need to be cut back all at once, but can be cut back in phases as leaves and stems dry and turn brown.

Leaf Litter Is Perfectly Natural

Mulch merely substitutes for leaf litter.

Forests lack gardeners. In the wild, there is no one to rake fallen leaves or blow them away. Foliage falls from trees and onto the ground, where it stays as it decomposes. It is the natural process. Raking and blowing leaf litter away is unnatural. It deprives the soil and organisms that inhabit it of significant organic matter that they crave. It also interferes with insulation and moisture retention.

Of course, there are some natural processes that are not so desirable in home gardens. After all, that is why raking and blowing is standard procedure. It is not practical to leave leaf litter on lawn, ground cover, pavement or roofs. Raking and blowing removes leaf litter from where it is unwanted, or at least moves it to where it is less visible. Leaf litter seems to be so useless and unwanted.

However, other procedures are necessary to compensate for the lack of leaf litter. Mulching insulates soil, retains soil moisture, and inhibits weed growth. Watering adjusts to deficient moisture in exposed soil. Weeding eliminates weeds that germinate and grow where there is nothing to inhibit them from doing so. Herbicide may be more practical. It is all so contrary to natural processes.

It is somewhat obvious why deciduous plants defoliate through autumn and winter. They do not need their foliage as much while days are shorter and sunlight is less intense. Also, they do not want to be battered by winter wind, or collect heavy snow. Yet, their desire to mulch their own soil is not so obvious. Evergreen plants do it also. They just do it slower, and generally throughout the year.

In fact, many evergreen plants are more efficient with their mulch than most deciduous plants are. Leaf litter of eucalypti, camphor, bay and nearly all conifers actually has a preemergent herbicidal effect. It inhibits germination of seed that can reach the soil. It can be a disadvantage for wildflowers, or an advantage for weed control. Incidentally, coniferous leaf litter is likely to be combustible.

Leaf litter, composted or left to its natural processes, is natural.

Collect Fallen Leaves Before Winter

Falling leaves will soon be accumulating in gutters.

The problem with all the colorful foliage that adorns so many of the deciduous trees in autumn is that it does not stay in the trees too long. Combined with all the other less colorful deciduous foliage, as well as whatever evergreen foliage happens to fall this time of year, it will become quite a mess by winter. Rainy and windy winter weather will only make it messier by bringing down even more foliage!

Contrary to popular belief, many evergreen trees are just as messy as deciduous trees are. Instead of dropping all their foliage in autumn or winter, most evergreens drop smaller volumes of foliage throughout the year. The mess is less obvious since it sneaks up slowly, but can accumulate over a few months. Only a few evergreen trees drop much of their foliage in more obvious seasonal phases.

Debris from evergreen trees is actually more likely to be a problem for plants below. Pines, cypresses, firs, spruces, cedars, eucalypti and many other evergreen trees produce natural herbicides that inhibit the emergence of seedlings of plants that would compete with them in the wild. In landscape situations, this unfortunately interferes with lawns, ground covers and annuals. Besides walnuts and deciduous oaks, not many deciduous trees use this tactic.

Regardless, any foliar debris can be a problem if allowed to accumulate too long. Large leaves, like those of sycamore, can accumulate and shade lawn, ground cover and some dense shrubbery, and can eventually cause mildew and rot. Finely textured foliage, like that of jacaranda or silk tree, can sift through most ground covers to the soil below, but can still make a mess on lawn.

Before rainy weather, debris should be cleaned from gutters and downspouts. Because some foliage continues to fall through winter, gutters will likely need to be cleaned again later. Flat roofs and awkward spots that collect debris, such as behind chimneys, should also be cleaned.

Gutters at the street are more visible and accessible, so do not often accumulate enough debris to be a problem, but may need to be cleaned if they become clogged with debris washed in by the earliest rains. Fallen leaves should be raked from pavement so that it does not get dangerously slippery, or stain concrete too much.

Color Is Not Black And White

Annuls must change with the seasons.

Several months ago, warm season vegetable plants replaced cool season vegetable plants. More recently, new cool season vegetable plants began to grow from seed, to replace warm season vegetable plants. Annual vegetables grow only within specific seasons. As they finish, they relinquish their space to those that grow in the next season. Annual color operates in the same manner.

‘Color’ is another word for ‘annuals’ or bedding plants that provide colorful bloom. Those that grew earlier were warm season annuals or summer annuals. Those that replace them through autumn are cool season annuals or winter annuals. Of course, there is nothing black and white about color. Some color from last summer can linger late. Some for next winter prefers an early or late start.

Furthermore, much of the color that cycles through gardens as annuals actually has potential to perform as perennials. If cut back and obscured by more seasonable color through their dormancy, some types can regenerate when it is again their season to perform. For example, cut back busy Lizzie that bloomed last summer can overwinter underneath primrose, and start over next spring.

Marigold and chrysanthemum can start bloom early, before summer ends, but may not perform for long. Some chrysanthemum bloom only once, before vacating their space for other cool season color that does not mind starting later. Cyclamen and ornamental cabbage happen to prefer late planting, to avoid Indian summer. Warmth causes cabbage to bolt, and promotes rot of cyclamen.

Pansy, viola and various primrose have always been popular. Sweet William, Iceland poppy and stock are not as common. Stock should be, since it is so delightfully fragrant. Both nasturtium and alyssum bloom nicely through either summer or winter, depending on when they started to grow from directly sown seed. Some fibrous begonia can perform through winter if sheltered from frost.

Most color does well from cell packs. Nasturtium should only grow from seed. Chrysanthemum and cabbage might be better from four inch pots. Cyclamen may only be available in four inch pots.

Snails, Weeds And Falling Leaves

Gardening does not slow for autumn.

The coloring of foliage is a bit slow this autumn. The cooling nights after such warm weather is bringing some of the deciduous foliage down while it is barely yellowing. Honeylocust and black oak have already gotten notably sparse without much notable color. Hopefully, the more colorful sweetgum, flowering pear, pistache and gingko trees will retain their foliage later into cooler weather, so that they can put on a worthy show before filling compost piles.

It is probably slightly too early to clean gutters and downspouts. Unless the rainy season somehow starts first, this should probably wait until most of the foliage that is expected to fall has already fallen. Lawns, certain ground covers, decks and pavement should be raked as needed though. Decks and pavement can get stained from the tannins that leach from decomposing foliage. Lawn and ground cover do not like the shade under the debris.

However, slugs and snails really dig the mess. Fallen foliage keeps the ground cool, damp and shaded. Raking leaves does not eliminate slugs and snails, but inhibits their proliferation. There are always plenty of other hiding places. As the weather eventually gets cooler and damp, snails that stay out in the early morning should be collected and disposed of. Of course this technique is not convenient for everyone, since most snails hide before the sun comes up. Small slugs hide earlier in the morning and are even more unpleasant to handle.

Once found, neither slugs nor snails are too elusive . . . or fast. Yet, plucking and collecting them is not a fun job. Once collected, no one knows what to do with them. They can be put into plastic bags and disposed of; and will eventually succumb. Some people prefer to simply toss them onto a dry and sunny driveway or roof where they succumb more quickly and get taken by birds. Snails may need to be squashed to limit mobility.

Even though it is too late to prevent most types of weeds from dispersing their seed, a few types continue to disperse seed as they deteriorate through autumn and winter. Weeds in areas that get watered last longer and disperse their seed later than those without watering. Perennial weeds that are still green in dry areas areas will be easier to pull after the first rain.