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Shear Abuse

Cascading rosemary should actually cascade rather than get shorn into submission. (For this situation, it is subordinating to the climbing Boston ivy below.)

You can make fun of the decadent hair styles of the 1980s all you like; but you must admit that they were better than what came later. Back then, the assets of each particular type of hair were exploited instead of destroyed; sculpted instead of chopped into submission. Sadly, landscape maintenance evolved in a similar manner.

So many trees, shrubs and ground covers are either shorn too much to develop their naturally appealing forms, or not pruned severely enough to allow space for resulting new growth to mature and bloom like it should. Gardeners are notorious for shearing anything within reach. However, they are also notorious for allowing certain ground covers to get too deep and overgrown.

Trees that are short with multiple trunks when they first get planted are more likely than taller trees with single trunks to be shorn into nondescript shrubs. Olive, Japanese maple, tristania (laurina) and crape myrtle are commonly victims of this abuse. They are not only deprived of their form, but their grace and foliar appeal as well. Shorn crape myrtle may never be able to bloom.

Oleander, bottlebrush, arborvitae and various pittosporums that make nice informal screens in their natural forms are likewise very often shorn inappropriately and needlessly into all sorts of odd geometric shapes. Fortunately, pittosporums tend to make excellent formally shorn hedges as well as informal screens. Yet, when shorn without a plan, they more often develop into herds of noncontinuous geometric shapes. Oleander and bottlebrush, like crape myrtle, may never bloom if shorn too frequently.

Ground cover more often has the opposite problem. It does not get mown enough, or otherwise pruned down to stay shallow. This may not be a problem in most of the space covered by ground cover, but does make for hedge-like edges where the ground cover meets walkways, with all the problems of improperly shorn hedges. These edges can be softened if sloped inward and rounded off on top. However, lantana, star jasmine, acacia redolens and the ground cover forms of ceanothus do not bloom on these shorn edges unless the shearing procedure gets done at the right time to allow for enough new growth to mature in time for the blooming season.

There is certainly nothing wrong with properly planned and properly shorn formal hedges; but not everything needs to be shorn. Plants should be selected to be proportionate to their particular application without abusive shearing. Like the hair styles of the 1980s, the assets of each particular plant should be exploited instead of destroyed.

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Utility Clearance Can Disfigure Trees

Utility cables need clearance from trees.

Last winter was a doozy! It involved historic frost, snow, rain, wind, floods and mudslides. A few roads remain closed in some regions. Major electrical outages were too numerous for prompt repair. Weather alone did not cause such outages though. It merely dislodged vegetation that did so. This demonstrates the necessity for utility clearance maintenance.

Utility pruning is a specialized but very often unpleasant sort of arboriculture. It maintains necessary clearance between vegetation and utility cables. Its unpleasantry derives from its harsh efficiency. Clearance is the priority. Proper arboricultural technique is not. There is no compromise. Trees that encroach too closely to cables are likely to regret doing so.

Proper arboricultural procedures are too expensive to justify for utility clearance pruning. Otherwise, electricity and other utilities that utilize cable would be much more expensive. Besides, for many trees within utility easements, proper arboriculture is impossible. They can not accommodate necessary pruning without disfigurement. Several can not survive such disfigurement.

Palms, for example, can not survive without their single terminal buds. They lack limbs to divert growth to. Removal of a terminal bud that encroaches too closely to utility cables is lethal. Palms generally grow only upward. Those that grow tall rapidly can not live below utility cables for long. Very few palms remain low enough to maintain minimal clearance.

Excurrent trees are generally more vulnerable to disfigurement than decurrent trees. The single central trunks of excurrent redwoods and spruces do not adapt to redirection. The several main limbs of decurrent oaks and elms are more cooperative. Compact trees that are unlikely to reach cables are least problematic. Of course, many trees are unplanned.

Arborists can repair some minor clearance pruning damage or disfigurement. They might prevent some damage by timely pruning for containment. Unfortunately, some damage is neither repairable nor preventable. Also, such procedures are too dangerous for anyone who lacks qualification for them. Typical garden enthusiasts must avoid electrical cables!

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Freeze Damage Necessitates Selective Pruning

Warmth stimulates recovery from freeze damage.

Pruning at the proper time has been a concern all winter. Dormant pruning was timely as soon as defoliation began. It remains timely almost until bloom. Pollarding and coppicing are generally although unnecessarily a bit later within that range. Spring pruning begins soon after bloom. Pruning of freeze damage starts after the last reasonable threat of frost.

Frost is as variable as the many climates here. Generally, it causes more damage farther inland and at higher elevations. Conversely and generally, it causes less damage closer to the coast and at lower elevations. Many southern coastal climates experience no frost. However, frigid air drains downhill. Within any plateau, the frostiest areas are the lowest.

Last frost dates should help with scheduling of pruning or grooming of freeze damage to vulnerable vegetation. The last frost date for a climate is the average date of its last frost. Frost becomes increasingly unlikely afterward. That is the best time to add warm season vegetables and annuals to the garden. It is also when to begin grooming freeze damage.

If not too unsightly, freeze damage lingers until the last frost date for two primary reasons. It shelters vulnerable tissue below, including any new growth that develops prematurely. Also, removal of such damage stimulates new growth that would be even more exposed and innately more vulnerable to frost. However, priorities change soon after the last frost.

Then, it becomes important to groom or prune away freeze damage prior to generation of fresh new growth. For milder climates, it is already timely to do so. It might be a while for less mild climates. Even for frostless climates, this might be a good time to groom growth that is only incidentally shabby. Such grooming gets more complicated with new growth.

Many zonal geraniums are already extending new growth up through shabby old growth. Removal of such old growth or freeze damage without damaging mingling new growth is no simple task. If new growth stretches for sunlight below old growth, it might flop without support from the old growth. It may be more practical to cut all growth back to regenerate. Canna also develop similar complications.

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Spring Pruning Breaks The Rules

Spring pruning allows bloom to finish.

Dormant pruning is the best pruning. It happens while the subject plants that benefit from it are dormant and unaware of such procedures. Such procedures would be significantly more distressing to plants while they are vascularly active. In comparison, spring pruning may seem to be cruel and tortuous. Nonetheless, it is justified for particular applications.

For most plants that benefit from dormant pruning, the worst time to prune is immediately after the best time. Such plants are most vascularly active while blooming and refoliating during early spring. They become more resilient to pruning as they finish bloom and their foliage matures. This generally applies to plants that benefit from spring pruning as well.

The primary difference between plants that prefer dormant pruning and plants that prefer spring pruning is their primary purpose. Several plants that benefit from dormant pruning produce fruit. Plants that benefit from spring pruning merely produce profusion of bloom. Dormant pruning concentrates resources. Spring pruning allows maximum spring bloom.

For example, flowering plum is like a sterile but prettier version of fruiting plum. It merely blooms impressively without subsequently fruiting. There is no need for dormant pruning to concentrate resources into fruit, or to compensate for fruit weight. When and if pruning becomes necessary, it can happen after any unwanted growth has contributed to bloom.

Flowering cherry, flowering crabapple and flowering quince may actually prefer dormant pruning like their fruitful relatives do. However, like flowering plum, they also bloom more abundantly prior to spring pruning. Unrelated dogwood, redbud, forsythia and even New Zealand tea tree likewise benefit from spring pruning, which is the same as late pruning.

In moderation, blooming stems of plants that get either dormant or spring pruning can be delightful as cut flowers. A few unpruned stems can remain after dormant pruning for that purpose. They only need proper pruning when harvested or after bloom. Likewise, plants that get later spring pruning after bloom can likely spare a few stems while still blooming. Alternatively, such stems should be conducive to forcing.

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Coppice To Renovate Overgrown Shrubbery

Coppicing stimulates vigorous new basal growth.

Pollarding is extreme pruning. It removes all but the most substantial of limbs and trunks. Coppicing is even more extreme. It leaves only stumps above ground. Both are common and respected arboricultural techniques outside America. However, they are vilified here. Actually, very few arborists here know how to pollard and coppice properly, or admit to it.

There are many valid reasons to pollard or coppice trees or big shrubs. Both techniques stimulate vigorous growth. Lush foliage of such growth is useful as fodder, particularly for silkworms. Elongated stems of such growth are useful for basketry and kindling. Species that bloom on older stems can not produce pollen or messy fruit after annual procedures.

Although silkworms, basketry and such are unimportant within an average home garden, proper pollarding or coppicing enhances vigor. This enhances the bloom of species that bloom on new stems. Vigorous growth of pollarded crape myrtle is atypically resistant to mildew, and also blooms zealously. Coppice pruning eliminates unsightly thicket growth.

Pollarding is generally useful for trees and large shrubs that retain primary trunks. Only a few of the many species that inhabit home gardens are conducive to it. Since secondary growth is initially structurally deficient, it will most likely need subsequent pruning during subsequent winters. Some vigorous pollarded trees are dependent on annual pollarding.

Coppicing is generally useful for large and vigorous shrubbery, and perhaps a few types of trees. Coppiced shrubbery is not as reliant on subsequent pruning as pollarded trees. They either benefit from pruning as they grow anyway, or do not get too heavy to support their weight. Both coppice and pollard pruning can happen only during winter dormancy.

Realistically, the majority of plants in home gardens are conducive to neither coppice nor pollard pruning. Cypress hedges die if cut back to stumps. Grafted plants, even if pruned above their graft unions, are likely to regenerate from their understock. However, some of the most popular hedge plants, such as privet, holly, photinia, osmanthus, English laurel and bottlebrush regenerate splendidly.

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Deciduous Fruit Trees Need Specialized Dormant Pruning.

Apple and other pomme fruit trees are pruned very differently from stone fruit trees.

It seems unfair that so many deciduous fruit trees are available without warnings that they need such specialized maintenance. They are certainly worth growing. Otherwise, not many of us would grow them. Yet, those of us acquiring fruit trees for the first time should be aware that, with few exceptions, deciduous fruit trees need specialized and meticulous pruning while dormant every winter.

The pruning these trees require is too specialized to explain in a few short paragraphs; but can be researched for each particular type of fruit tree. Sunset publishes an excellent book about ‘Fruit Tree Pruning’, that illustrates and explains the different types of pruning that each different fruit tree needs. Pruning is the sort of thing that gets better with experience; so even though the pruning gets more involved over the years as the trees grow, the procedure becomes more familiar.

Without pruning, deciduous fruit trees produce more fruit than they can support, which disfigures and breaks branches as the fruit matures and gets too heavy. Even if limbs do not break, overabundant fruit is often of inferior quality because the trees that produce it exhaust their resources. Fruit of well pruned trees may not be as abundant, but is typically better. Besides, pruning is good arboricultural hygiene, keeping trees vigorous and more resistant to disease.

The stone fruits probably need the most severe pruning. These are fruits like apricots, plums, prunes, nectarines and peaches, that have hard pits or ‘stones’. They develop fruit on stems that grew during the previous year. Generally, these stems need to get cut back short enough to support the weight of the fruit that will develop in the next season. Dead, dying, damaged and diseased stems, known as the four ‘D’s, should be pruned out completely.

Cherries and almonds are the exceptions to the generalization about severe pruning for stone fruit, since the trees can support the weight of the fruit. They only need pruning to eliminate the four ‘D’s and to limit height. Because almonds get shaken from their trees instead of picked, they are often allowed to get quite tall, and can even function as small shade trees. Peaches are the opposite extreme since their fruit is so large and heavy, necessitating the harshest pruning.

Pomme fruits like apples and pears need similar but somewhat different pruning, which preserves stunted ‘spur’ stems that produce fruit low on older stems for many years. Like cherries, certain pears may not need much pruning. Certain apples need more pruning than others. Again, the needs of particular trees are best learned from experience.

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Dormant Pruning For Roses

Proper pruning during winter promotes the best roses during summer.

(This recycled article is eleven years old. Therefore, the event that it describes is no longer relevant.)

Just about anyone can plant roses in the garden, and care for them for at least the first year. Pruning them properly while they are dormant in winter in order to get them to perform satisfactorily every subsequent year is what most of us who grow roses have difficulty with. Like deciduous fruit trees, roses should not be planted and expected to perform with minimal attention. They certainly should not be pruned with hedge shears!

The once modern, but increasingly old-fashioned, hybrid T roses have traditionally been the most common victims of inadequate pruning, since they need such aggressive pruning every winter to prevent overgrowth that interferes with healthy cane growth and bloom. More modern cultivars (cultivated varieties) designed to resemble older roses, as well as reintroduced old fashioned roses are generally not so demanding, but likewise perform best with proper dormant pruning. There are slightly, and not so slightly, different ways to prune the different types of roses. Even the ‘low maintenance’ carpet roses should be pruned to some degree.

Fortunately for those of us who are just learning about roses, the first of several free rose pruning lessons in the San Jose Heritage Rose Garden began this morning, January 4. These hands-on lessons continue at 9:00 a.m. every Wednesday and Saturday until late February. Participants meet in the center of the Garden. The minimum age to attend is sixteen; but minors without parental supervision require a signed minor release form that can be obtained from the Guadalupe River Park Conservancy.

Participants should bring bypass shears, leather gloves, closed-toe shoes and preferably a water bottle. Those who lack shears or gloves can borrow what they need at the Garden. The Heritage Rose Garden is located on West Taylor Street near Walnut Street in San Jose. Parking can be found on Seymour, Taylor or Walnut Streets. More information can be obtained by email to Emily of the Guadalupe River Park Conservancy at emily@grpg.org or by telephoning 298 7657.

The Heritage Rose Garden is the most complete collection of old world roses, the ancestors of modern roses, in the world! Although it lacks modern cultivars, it exhibits a remarkably extensive variety of roses, with all sorts of growth habits. There really is no other garden where one can prune roses with the same basic techniques in so many different ways.

Incidentally, modern hybrid T roses derive their designation from the ‘T budding’ technique employed to attach the scion (upper blooming portion) to the understock (roots), not because the rose hips (fruiting structures) are used to make tea. However, all sorts of roses, including floribundas, polyanthas, grandifloras and all sorts of climbing roses, are budded by the same means; and many hybrid T roses are actually grown on their own roots and not budded onto understock at all. The designation of hybrid T seems somewhat out dated, but is still effective.

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Dormant Pruning Enhances Fruit Production

Dormant pruning may not be pretty.

Adding new fruit trees to a garden is reasonably easy. Maintaining them properly as they mature is more of a challenge. Centuries of extensive breeding to enhance production of such trees has also increased their reliance on horticultural intervention. Most deciduous fruit trees consequently need specialized dormant pruning during their winter dormancy.

Without adequate dormant pruning, most deciduous fruit trees are unable to support their unnaturally large and unnaturally abundant fruit. Dormant pruning actually enhances the size and quality of fruit. However, it also limits the weight of excessiveness, and confines it to sturdier branch structure. It concentrates resources into fewer fruit of superior quality.

Dormant pruning, or winter pruning, likewise concentrates resources into more docile but healthier vegetative growth. It eliminates or at least diminishes the 4 Ds, which are dead, diseased, damaged and disfigured growth. Confinement of potentially rampant stems not only improves structural integrity, but also limits wasteful production of unreachable fruit.

Almost all deciduous fruit trees, and most nut trees, require specialized dormant pruning. So do grapevines, kiwi vines, berry canes and roses. Evergreen fruit trees, such as citrus and avocados, are exempt for now though, since such pruning promotes new growth that is vulnerable to frost. Most of such trees do not require such aggressive pruning anyway.

Almonds, apricots, cherries, nectarines, peaches, plums, prunes and all their hybrids are stone fruits of the genus Prunus. Almonds are actually seeds, or stones, of leathery fruits that are merely hulls. Various stone fruits need various degrees of similar pruning. Heavy peaches need aggressive pruning. Lightweight cherries might need only minor trimming, or no pruning at all.

Apples, pears and quinces are pomme fruits that, like stone fruits, need various degrees of similar pruning that conforms to their distinct characteristics. Persimmons, mulberries, pomegranates and figs each need specific types of pruning as well. Familiarity with each of the dormant pruning techniques that each fruit tree in the garden requires is essential.

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Getting an early start to winter pruning may have certain advantages

Without specialized pruning, fruit trees become sloppy and unable to sustain all of their fruit.

As long as it gets done well before buds begin to swell late in winter, the meticulous and specialized pruning that deciduous fruit trees and roses require during winter dormancy does not need to be done immediately. Here where the climate is so mild, some roses may still be blooming. The main advantage to getting an early start is that those of us who have many fruit trees and roses in need of pruning have more time to get them all done within the proper time.

If it helps to start pruning early, it is best to prune fruit trees and roses in the same order that they go dormant and defoliate. The ‘stone’ fruits (those of the genus Prunus, that have large pits known as ‘stones’), like apricots, cherries, nectarines and peaches typically defoliate earlier than the ‘pomme’ fruits, like apples, pears and quinces. Modern ‘carpet’ roses may not defoliate completely, so can be delayed until after all the bare roses get pruned, but may eventually need to get pruned while still partially foliated.

The specialized pruning that deciduous fruit trees and roses need is serious business. Those who do not know how to do it properly should learn about it before actually doing it. Improper pruning of fruit trees can inhibit production and damage the trees. Roses are not so easily damaged, but will get overgrown and not bloom as well if not pruned aggressively enough. (This sort of pruning will be a topic later in the season.)

Like fruit trees and roses, other trees and shrubs that need pruning prefer to be pruned while dormant through autumn and winter. Deciduous trees and shrubs are obviously dormant while bare, but realistically, are ready to be pruned when their foliage is no longer green.

Evergreen plants are not so obviously dormant, but will be as dormant as they get through winter. This would therefore be a good time to prune to eliminate pine limbs that are too low. If pruned a bit early, the pruning wounds will get weathered more through winter and consequently bleed less through spring.

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Vegetation Needs Clearance From Infrastructure

There is a chimney under this overgrown vine.

It may not seem like it is so now, but evergreen trees really are messier than most deciduous trees. They probably do not produce any more debris, but they drop their debris over much longer periods of time, or at various times, or simply ALL the time. Yet, at this time of year, it seems like the deciduous trees that mostly have dropped nothing or very little since last year, are making most of the mess in the garden as they defoliate for winter.

Defoliation is only beginning, and will continue for a while. Ironically, the most impressively colorful deciduous trees happen to be those that hold their foliage for a long time, making their defoliation process linger over a few months. Even the most efficiently neat trees that defoliate in a few days tend to do so during windy or rainy weather, when we are not so motivated to go out into the garden to clean up their mess.

As the rainy season begins in a few weeks or so, the gutters on the eaves should be cleaned of debris that has accumulated since last year. This can sometimes be delayed until all deciduous trees that contribute to the accumulation of debris are completely defoliated. Generally though, homes with many or big trees (or many big trees) may need their gutters cleaned more than once as they continue to collect debris through autumn and perhaps into winter.

Any debris that collects behind chimneys, in valleys (where roof slope changes direction) or anywhere else on the roof, should also be removed. Even without gutters to collect debris, flat roofs collect whatever debris that does not get blown off by wind. Only parapet roofs that are common on so many homes of Spanish architecture collect more debris, since they are sheltered from wind.

Trees and vines should never be allowed to lean onto roofs. Vines and some densely foliated trees tend to accumulate all sorts of debris that rots and then damages the roof below. Trees that touch roofing material are abrasive as they move in any breeze.

Obtrusive trees and vines are also a serious problem for chimneys. Cypress, cedar, pine and the beards (accumulations of dead foliage) of fan palms are particularly combustible. Even after they get soaked by rain, they can quickly dry if heated by the exhaust from a chimney. Maple, ash and other trees with open canopies may not be as combustible, especially while defoliated, but can get roasted by chimney exhaust, and can interfere with ventilation.