Winter Pruning Of Fruit Trees

90130thumbThe vast orchards of the Sacramento and San Joaquin Valleys might make the impression that production of fruit is easy. The trees naturally bloom in spring, and develop fruit over summer, as if they do most of the work prior to harvest. In reality, those trees have been so extensively bred to maximize production that they need, among other maintenance, very specialized pruning in winter.

Without pruning, deciduous fruit trees produce more fruit than they can support. The weight of the fruit breaks and disfigures limbs. Excessive fruit production exhausts resources so that, although more fruit is produced, it is of inferior quality. Diseases and insects proliferate in crowded stem growth that lacks vigor. Unharvested fruit that is beyond reach in upper growth may attract rodents.

Well pruned deciduous fruit tree produce fruit of much better quality, and are able to support it on well structured limbs that are reasonably within reach. They are less susceptible to diseases and insects. Such pruning seems severe to those who are unfamiliar with it, but it is necessary, and the trees appreciate it. Because it is so severe, it is done while trees are dormant through winter.

Different types of fruit trees need distinct types of pruning. Furthermore, different cultivars of each type may need different degrees of the same type of pruning. All should get the ‘four Ds’, which are ‘dead, dying, damaged and diseased’ growth, pruned out of them. Because figs produce early and late crops, they can be pruned less for more early figs, or more severely for more late figs.

Most of the deciduous fruit trees are either stone fruits or pomme fruits. The stone fruits include apricot, plum, prune, nectarine, peach and cherry, which are all of the genus of Prunus. Pomme fruits are apple, pear and quince. Because the winter pruning of deciduous fruit trees is so specialized and so intensive, it is worth studying, preferably before planting the fruit trees that require it.


Prune Now For Roses Later

70524thumb+The main problems with roses locally are not related to climate, soil, insects or disease. Warm and semi-arid climates of California happen to be some of the best places in the World for roses. Sure, many roses have problems with insects such as aphid, and diseases such as powdery mildew, but primarily because such pathogens proliferate among roses that are not pruned properly.

Yes, the main problems with roses are a direct result of improper pruning. Without adequate pruning, roses become overgrown thickets that shelter the pathogens that afflict them, but also lack the vigor to be resistant to damage. Like so many other domesticated plants, they were bred for maximum production of unnaturally big flowers, at the expense of natural resistance to pathogens.

Pruning eliminates superfluous growth and improves air circulation, which interferes with the proliferation of most types of pathogens. Most pathogens overwinter in fallen foliage that should get removed in the process. Pruning also concentrates growth of the next season into fewer new stems, which stimulates vigorous growth that hopefully grows faster than the pathogens that infest it.

Roses should be pruned while dormant in winter, after defoliation, and before buds start to swell at the end of winter. Hybrid tea, floribunda and grandiflora roses should be pruned back to only about three to six canes that grew from the base during the previous year. Older canes should be removed. Remaining canes should be only about two feet tall, and cut just above a healthy bud. Any growth below the graft union (where the basal canes originate) are genetically different suckers (from the understock or rootstock) that must be removed.

As growth resumes in spring, well pruned plants will produce fewer stems and blooms that are significantly more vigorous than those of inadequately pruned plants. Overgrown and inadequately pruned plants must spread their resources thin amongst more but significantly weaker stem growth that is much more likely to be damaged by pathogens. Aggressive pruning now pays off later.

The Rose And Fall . . .

p90113Winter is for pruning. Any good native of the Santa Clara Valley knows that. It starts as soon as the first deciduous fruit trees defoliate and continues to the last minute rush to finish before the buds start to swell at the end of winter. It may seem like there would be no last minute rush now that all the orchards are gone, but there is so much in landscapes to prune that prioritizing and scheduling pruning takes a bit of effort. Just like we know that apples and pears can be pruned slightly later than apricots and prunes, in the landscape, we know that sycamores might be delayed until the birches are done. Naturally, I feel compelled to prune the flowering cherries and fosythias, but am almost content to wait until after they finish blooming in early spring. Of course, I cringe as I write this.
Roses are getting pruned now. I first finished a few scrawny hybrid tea roses, including a few ‘tree roses’. They really should be relocated to a sunnier spot, but not this year. Afterward, I did a row of climbing roses that are not exactly climbing the fence that they were planted against. They really should be moved too, but like the others, not this year. I still need to prune a bank covered with modern carpet roses. I am none too keen on them. Actually, I rather dislike them. However, of all the roses, they are the only ones that happen to be in the right situation, and are doing a nice job.
Just before I started with the first batch of hybrid tea roses, I pruned a single potted hybrid tea rose that is all alone on a deck across the street. I wanted to get it done when I thought about it so that I would not forget about it in the process of pruning everything else. It had bothered me for some time because it was so tall. I mean, I could not reach the top of it. The blooms up there were closer to upstairs windows than to anyone wanting to seem them from ground level. The supporting lower canes were bare of foliage, but well armed with nasty thorns. Honestly, I thought that the deck would have been more inviting without it.
Pruning it was rather simple; just three major cuts. Since the rose is where people mingle, I chopped the thorns just so that they are not so sharp. The remaining three canes were older than one year, but did not seem too terribly old. In fact, there was still a bud to cut back to on one of the canes. For the other two, I had to cut back to old petiole scars, expecting that dormant buds are still in there. That was about it.
The problem that I was not aware of is that the rose was left that tall intentionally because a former gardener liked it that way! Now I feel badly. I really thought that it had just been neglected. Like I mentioned, the canes did not seem to be several years old. They must have replaced older canes in just the last few years. Regardless, I can not put it back. In the partial shade there, it will probably grow back as tall within the year. I hope that the former gardener does not find out about it before then. I know that if someone did that to a roses that I had pruned in a specific manner, I would be really angry about it.p90113+

Horridculture – Miss Congeniality

p90109Now, before I commence with my rant and long list of problems with this picture, I should mention that this seemingly abused rose tree does seem to be appreciated. All the roses in this landscape seem to be very healthy, and they bloom constantly between spring and autumn. Their performance suggests that they are regularly fertilized and deadheaded.
The unusually brutal pruning may be an attempt to keep this particular rose tree as compact as possible, within very limited space. It is not how I would do it, but perhaps it helps. The size of the burl suggest that this rose tree has been pruned effectively like this for a few years, although the lack of weathering of the labels indicate that it is not more than several years old. Older canes really do seem to be getting pruned off annually as they should. Even though the remaining canes are stubbed much too short, the end cuts are done properly. I can not help but wonder of pollarding back to the main knuckle would be just as effective, and neater.
The labels seem to be retained intentionally. In fact, the smaller white label to the left is attached to a new cane. Either the label was removed from an older cane that was pruned away, and attached to a new cane intentionally, or the rose tree was planted only last year rather than a few years ago, as mentioned earlier. I do not know why this uninformative label would have been retained; but the other larger label might be there for anyone who wants to know the name of the rose when they see it blooming in season. It happens to be in a very trafficked spot, where people walk by it constantly.
Rather than snivel about the (seemingly) very bad pruning, and the retention of the (trashy looking) labels, I should just say that this apparently appreciated rose tree should have been planted somewhere else in the garden, or not at all. That wheel in the background really is in a parking spot that is bordered by the red curb. A tiny bit of another red curb on the opposite side of this very narrow space is visible in the very lower right corner of the picture. (I can not explain why the curbs are red.) This really is a very narrow spot between a parking space and a walkway! Those mutilated stems to the right are another shrubbier rose. Thorny rose canes could really be a bother for those getting out of or into a parked car, or walking by on the walkway. The seemingly useless stake might be there so that the rose tree does not get yanked over when it grabs onto someone. To make matters worse, this rose is a grandiflora, which wants to grow bigger and wider than most other types of roses. Defoliation during winter dormancy is no asset either. The pathetic marigold on the ground really does not help much.
The point of all this is that more thought should have gone into planting this rose tree here.
Even Miss Congeniality, who so proficiently adapts to the most unfamiliar of situations, has certain limitations; and this situation demonstrates the worst of them.

Horridculture – Clearance

P90102Many arborists mark certain lengths on their pole saws and pole pruners. When stood upright, these marks designate the standard heights for minimal clearance pruning. Not so many need to mark the height of minimal clearance for walkways, since they will prune away anything that is within reasonable reach with hand tools from the ground. The minimal clearance above parking spaces is not so easy to guess at, so is more likely to be marked on poles. So is the minimal clearance over roadways, where the lowest limbs must be high enough to be out of the way of campers and freight trucks.
Clearance to the sides is determined by the location of the curb, but even that might need to be modified at sharp turns, or where the roadway slopes significantly away from the center. Clearance must similarly be a bit higher over dips in a roadway, where the height of long freight trailers would be affected by the elevation of the wheels in front and back (outside of the dips). Clearance around street lighting, roofs, utilities and such is determined by the object that requires clearance, so no marks must be made on the poles for such work. (Clearance pruning of high voltage cables is only performed by those who are qualified to do so.)
Clearance pruning is serious business for arborists. They do not want their trees to hurt anyone, or to damage vehicles. Nor do they want their trees to be damaged by vehicles. Obtrusive limbs can be torn away by freight trucks. Even if not torn away, limbs that are regularly battered by freighter trucks are rather unsightly.
As someone who used to drive the delivery truck, I can tell you that clearance pruning is also important for some of us who use the roadways.
These three young Italian stone pines are healthy specimens that are probably well structured inside all of the outer foliage. It is hard to say, since I can not see inside through all the disfigured lower foliage that has been continually battered by truck traffic. They probably only need to be pruned for clearance above and away from the traffic. If pruned to establish a minimal ceiling just two feet or so above the obvious damage, and to remove all the lower growth to the side, they would be excellent street trees for many years. They will eventually need to be pruned again, as maturing branches sag from their own weight, but that is to be expected. The main trunks and bulky limbs within would probably be quite sculptural if they were to be exposed by pruning that is necessary anyway. It really would not take much.

Prune Now For Fruit Later

70726thumbModern fruit trees have been so extensively bred to produce abundant and unnaturally large fruit, that most types are unable to support the weight of the fruit that they can produce each season. Without specialized dormant (winter) pruning to limit production, the weight of excessive fruit breaks and disfigures the limbs of the trees that produce it. Fruit becomes too much of a good thing.

Pruning not only limits the weight of the fruit; but it also improves the structural integrity of the limbs that must support it, and ideally, keeps fruit more reachable. Concentrating resources produces fewer but better fruits, instead of wasting resources on excessive fruits of inferior quality. Fewer stems that grow in spring are more vigorous and resistant to disease than more stems would be.

‘Stone’ fruits (of the genus Prunus) generally get similar pruning. However, peaches and nectarines produce such heavy fruit that they get pruned more severely than apricots, plums and prunes. Cherries and almonds are so lightweight that they may not need to be pruned at all. Cherries may be pruned for height. Since almonds get shaken from their trees, height is not so important.

Stems that grew last summer should produce fruit next summer. They should therefore be pruned short enough to support the weight of the fruit that they can produce (or what stems produced in previous years). For peaches, stems may need to be pruned to only a few inches long, even if the new stems are several feet long. Upper stems that get too high can be pruned out completely.

Apples and pears benefit from the same sort of pruning, but can be cut back even more aggressively, since their new stems tend to be more productive at the base. Crowded clusters of vigorous new stems can be thinned to eliminate the largest and most dominant stems. Stunted ‘spur’ stems that do not elongate more than two inches or so each year many not need to be pruned at all.

The ‘four Ds’, which are ‘Dead, Dying, Diseased and Damaged’ stems, are the first to get pruned out, even if they happen to be in the right places. There is just too much potential for problems later. Young trees that do not need much pruning now should be pruned for structure. Dormant fruit tree pruning is so important and specialized, that it is worth studying in more thorough detail.

Horridculture – Disdain For Bloom

P81212From the same landscape that, last autumn, was so dutifully deprived of its elegantly cascading rosemary and soon to be fiery autumn color of Boston ivy, , I procured these disturbing images of what results from of a serious disdain for flowering crabapple bloom. These trees were mentioned earlier in that article, but without such images. Similar victims were discussed last spring, and about a year ago .

The landscape where these trees live was actually rather well designed, and for a few years, had been well maintained. Seriously! The flowering crabapples were likely selected because they would not get tall enough to encroach into the utility easement above. There were pruned as much as necessary to prevent them from developing into a nasty thicket like young flowering crabapples typically do, but without significantly compromising the spectacular bloom. They really were spectacular!P81212+

About six years ago, a different crew of ‘gardeners’ was hired. It was obvious when it happened because the brutality to other features of the formerly well maintained landscape was so immediate. These flowering crabapples were somehow spared, but only temporarily. They were at their prime when they displayed exemplary bloom for the last time three springs ago. As these pictures indicate, they were hacked back two springs ago, just as the fat floral buds were showing bright pink color, and were about to pop open. All the buds and blooming stems that the trees had put so much work into were cut off and taken away, just days or maybe hours before the big show. The process was repeated in the same manner just prior to bloom last year. A scarce few twigs were somehow missed, and managed to bloom with a few blossoms that developed into the few fruits that can be seen in the second picture. I can not explain why the hacking was done earlier this year. Nor can I explain why a bit more of the twiggy growth remains. Did the ‘gardeners’ leave it for a tiny bit of bloom, or were they just lazy with their mutilation. It does not matter. As long as these trees get hacked like this, they are ruined. The client pays the ‘gardeners’ to do this.

Now, these trees could only be salvaged by renovation. This would involve pollarding, which would remove the tangles of gnarled stubs, but would leave horridly stubbed limbs to start the regeneration process. The trees would be just as deprived of bloom for the first year, but would at least be able to compartmentalize (heal) the wounds on the cleanly stubbed limbs. The secondary growth would need to be very meticulously and systematically groomed and pruned for many years to replace the canopy. It is possible, but would involve more work than even a good horticulturist or arborist would want to devote to the project.P81212++

Bad Root Pruning

P81118-Root pruning is nothing new. It is done more commonly than we think about for many aggressive perennials like lily-of-the-Nile, that like to disperse their roots into areas where we want to grow more docile annual bedding plants or vegetables. We might do it halfway, or more, around a shrubby plant during spring or summer if we plant on digging and moving it the following autumn. For most small and low profile plants, root pruning is sort of tolerable. The plants that we do it to may not like it, but it is sometimes necessary, and better than not doing so.
Trees are not like most small and low profile plants. Most are very sensitive to root pruning when mature. They are not so proficient at replacing the portions of their root systems that they are deprived of. Large roots that get severed are very susceptible to decay, which slowly migrates inward to the rest of the root system. Obviously, depriving trees of roots compromises stability to some extent. Because roots are below grade, it is impossible to know the extent of the damage caused by root pruning while it is being performed. This is a classic example.
The exposed freshly cut surface to the left in the picture above is not the stump of a small tree that was just cut down. Although it is, in this picture, a horizontally oriented cut surface of what seems to have been something that was standing vertically, it was actually cut vertically through a horizontally oriented root. Yes, that is it in the yellow oval to the right. It was cut because it was displacing the adjacent asphalt pavement, as demonstrated by the picture below. Rather that trouble us with this concern, the resident of the adjacent home cut the root of this mature photinia tree to protect his driveway from more damage.P81118+

The problem was that the major root that was severed was all that was supporting the tree. (The cut surface of the severed root is in the middle of the picture below.) The roots to the left and right of it may seem to be substantial in the picture below, but were mostly decayed stubs left from earlier root pruning. I was able to wrestle the stump out to dispose of it, without cutting more roots. The lack of other substantial roots is probably why the primary root was so big and expanding actively enough to displace the pavement.P81118++

The funny thing about all this is that I would have done the same thing. I would have determined that, although the tree would be very distressed by the loss of such a major root, it should not have been too terribly destabilized, and should have been likely to eventually recover. Even if it eventually succumbed to the distress, the loss of this mature but small tree would have been a better option relative to continued damage to the paved driveway. I certainly would not have expected it to simply fall over as it so comically did. The picture below shows what had been vertical trunks of the photinia tree that were quite horizontal after it fell over. The fractured asphalt pavement is visible at the far right edge. The top of the tree reached the center line in the adjacent roadway. I am sorry that I did not get a more amusing picture of it blocking the lane. I was in too much of a rush to clear the roadway at the time. This was something that I really was not expecting to encounter at work.P81118+++

Glossy Abelia

50916With indiscriminate pruning, glossy abelia, Abelia X grandiflora, will never develop its natural form, with elegantly long and thin stems that arch gracefully outward. Sadly, almost all get shorn into tight shrubbery or hedges that rarely bloom. If only old stems get selectively pruned out as they get replaced by fresh new stems, mature shrubs can get eight feet tall and twelve feet wide.

Against their bronzy green foliage, the tiny pale pink flowers that bloom all summer have a rustic appeal. In abundance, they can be slightly fragrant. The tiny leaves are not much more than an inch long. Vigorous young canes that shoot nearly straight out from the roots slowly bend from the weight of their bloom and foliage as they mature.

Partial shade is not a problem for glossy abelia, but will inhibit bloom somewhat. Young plants want to be watered regularly. Old plants are not nearly so demanding, and can survive with notably less water. If alternating canes is too much work to restore old and neglected plants, all stems can be cut back to the ground at the end of winter. New growth develops quickly.

New Canes Replace Old Canes

50916thumbHeavenly bamboo, or simply ‘nandina’, is one of those many plants that almost never performs like it should. The intricately lacy foliage is so appealing while plants are young, and changes color with the seasons. The red berries can be comparable to those of holly. Unfortunately, healthy plants grow, and then ultimately get shorn into globs of disfigured leaves and stems.

The same abuse afflicts Oregon grape (mahonia), mock orange (philadelphus), forsythia, lilac, abelia and all sorts of shrubby plants that really should be pruned with more discretion. Their deteriorating older stems should be pruned to the ground as new stems grow up from the roots to replace them. It is actually not as complicated as it seems.

This pruning process, known as ‘alternating canes’, prunes the plants from below. It is a standard pruning technique for maximizing production of blackberries, raspberries and elderberries. It is similar to grooming old stalks from bamboo and giant reed, even if it does not prevent them from spreading laterally.

The deteriorating older stems, or ‘canes’, are easy to distinguish from newer growth. Old canes of Heavenly bamboo and Oregon grape become heavy on top, and flop away from the rest of the foliage. Old canes of mock orange and lilac get gnarled and less prolific with bloom. Aging abelia and forsythia canes become thickets of crowded twigs.

The newer stems are likely a bit lower, but are not so overgrown. Since the foliage is not so crowded, it is displayed on the stems better. Their blooms or berries are more abundant. By the time new growth becomes old growth, there will be more newer growth right below it. In fact, the regular removal of aging canes stimulates growth of new canes.

This is the time to prune Heavenly bamboo and Oregon grape, just because the oldest foliage is as bad as it will get after the warmth of summer. Mock orange, forsythia and lilac should get pruned while dormant through winter, but are commonly pruned just after they finish bloom early in spring. Abelia should probably wait until spring because new growth can look sad through winter.