Of all the stone fruit trees like apricot, plum and cherry, none need more aggressive and specialized pruning while dormant in winter than peach, Prunus persica. The distinctively fuzzy fruit is so big and heavy that the weight of too much fruit tears limbs down. Pruning not only limits fruit production, but improves structural integrity, fruit weight distribution, fruit quality, and tree health. Mature trees should be kept less than ten feet tall, but often get twice as tall with much of the fruit out of reach.
Only recently, and only to be more marketable, dried prunes attained the status of dried plums. Prunes and plums are actually two different types of fruit. Prunes are European fruits that dry nicely, but are not popular as fresh fruits. Plums are Japanese fruits that are best while fresh, but do not dry well at all. Because plums have less of a sugar content, they are likely to mold before they dry.
Plum is of the genus Prunus, just like prune and the other stone fruits. Stone fruits all contain large seeds, which are known as stones. Plums are ‘clingstone’, because the flesh of the fruit clings to the stones within. Prunes are ‘freestone’. Their stones separate easily from the flesh. The most popular plums are purplish or burgundy red. Others are blueish purple, red, orange, yellow or green.
Plum trees grow fast while young, and require aggressive pruning while dormant through winter. Otherwise, they get overwhelmed with fruit, and too tall to facilitate harvest. Even semi-dwarf trees can get almost twenty feet tall. They are spectacular in prolific white bloom. Small bare root trees that are now becoming available adapt to a new garden more efficiently than larger canned trees.
After centuries of breeding for abundant production of unnaturally large fruit, deciduous fruit trees have become dependent on specialized pruning while they are dormant through winter. Without pruning, most eventually become overgrown and overwhelmed by their own fruit. The weight of excessive fruit disfigures and breaks limbs. Pathogens proliferate within distressed foliage, crowded fruit and surplus fruit that falls to the ground.
Pruning not only improves the structural integrity of the limbs, but also limits the production and weight of the fruit that will be produced. Limiting production concentrates resources, so that there are fewer, but considerably better fruits, instead of too many inferior fruits. Concentrating the growth of the fewer new stems that develop in spring promotes vigorous growth that is more resistant to pathogens. Ideally, pruning also limits the height of fruit trees, so that much of the fruit develops closer to the ground.
Peaches, nectarines, apricots, plums, prunes, and cherries are all relates ‘stone’ fruits (of the genus Prunus), so require various degrees of similar pruning. Peach trees produce the heaviest fruit, so need the most aggressive pruning. Cherries trees produce significantly lighter and smaller fruit, so get pruned relatively minimally. Almonds (which are actually the ‘pits’ of a similar type of stone fruit) get shaken from their trees, so there is no advantage to keeping production close to the ground.
The ‘four Ds,’ which are ‘Dead, Dying, Diseased and Damaged’ stems should be pruned out first. Then the vigorous stems that grew last year should be thinned and cut back, but not removed completely. They are the stems that will bloom and develop fruit the following year. Pomme fruits, such as apples, pears and quinces, develop on similar newer stems that should likewise be pruned down, but many also develop on lower ‘spur’ stems that elongate so slowly that many spurs may never need to be pruned.
Most young deciduous fruit trees will need more pruning each year as they grow. Fortunately, pruning becomes more familiar with experience. Because pruning fruit trees is so specialized and important, it is worth studying more thoroughly.
Springtime in the Santa Clara Valley was famously spectacular decades ago, when vast orchards occupied what is now only urban sprawl. Tourists came to see it like some still go to see foliar color of autumn in New England. Most of the orchards were for stone fruits. Only a few in cooler spots were for apples and pears. Only orchards of English walnuts did not bloom colorfully.
Cherry and almond trees typically bloomed first. Prune trees bloomed immediately afterward. Apricot trees were only a few days later. Of course, the schedule of bloom was variable. Prune trees often bloomed just after apricot trees. Various cultivars of cherry started to bloom at slightly different times, even though those that needed to pollinate each other managed to do so.
After the main bloom of all the stone fruits, and after the tourists were gone, the few apple and pear orchards in cooler spots and surrounding hillsides continued the process. Mulberry trees that grew sporadically on roadsides around the orchards bloomed no more colorfully than English walnuts, but somehow produced enough fruit to distract birds from developing stone fruits.
Feral plum trees are a group that was not easy to categorize even before the demise of the orchards. They were not intentionally grown in orchards, or even in home gardens. They just sort of grew wild along creeks or from the roots of grafted stone fruit trees that had been cut down. They were originally grown as understock cultivars, but had naturalized to become truly feral.
Because their fruit was not used for much, they did not get much consideration. We tend to forget that some types bloomed before any of the other stone fruits. To those who do not expect fruit, feral plum trees are as spectacular as productive stone fruit trees.
Cher explained a long time ago that a half-breed is nothing to brag about. Some of us just don’t get it. A few clients still introduce me to their weirdly bred stone fruit trees as if they are both justification for great pride, as well as something that a professional horticulturist of the Santa Clara Valley has not already encountered a few thousand times. I at least try to act impressed.
The stone fruits that grew in the orchards of the Santa Clara Valley half a century ago were the best. That is why they were grown here. The climate and soil were ideal for their production. Traditional cultivars produced so abundantly and reliably that there was no need to breed new cultivars. The quality was exemplary. Consequently, only a few were actually developed here.
Half-breeds, or weird breeds of any unnatural ratio, started to be developed more than a century ago. A few happened incidentally where different species of the same genus of Prunus grew. They were enjoyed as novelties for home gardens, but were not sufficiently productive or reliable for orchard production. Their fruit was for fresh eating only, since it did not dry or can well.
Now that the orchards are gone, and the only stone fruits in the Santa Clara Valley are in home gardens, these weird half-breeds and others are becoming more popular. Nurseries will soon be stocking several along with their incoming bare root stock. There is certainly nothing wrong with them. However, they are not necessarily any better than their well bred ancestors either.
Apricot, cherry, nectarine, peach, plum and prune, as well as almond, are the traditional stone fruits, of the genus Prunus. (Almonds are the seeds or ‘stones’ of a stone fruit that does not get eaten, but instead gets discarded as a hull.) There are many cultivars of each. Some can be canned. Prunes and some apricots can be dried. There is no need for more, or for ‘improvement’.
Pluot, plumcot, aprium, apriplum, nectaplum, peacotum, pluerry and others like them are the weird interspecific hybrids (which are hybrids of two or more species within the same genus, which for these examples is ‘Prunus‘). Some are half-breeds. Some are breeds of different ratios, such as a half-breed with a half-breed parent, or a half-breed grandparent. It is confusing!
It is also an unjustifiable fad. There are more disadvantages to these weirdly bred stone-fruits than there are advantages. They really don’t get the best of both parents, but might get half of each. Again, there is certainly nothing wrong with that. There are those who legitimately prefer such hybrids. The point is that fads are not necessarily good, and many are just plain weird.
Growing fruit trees is quite a bit of work. While producing, some of the fruit trees need nearly as much attention as annual vegetable plants in the vegetable garden. Then, while dormant, they need meticulous and specialized pruning. Some fruit trees get damaged by insect or disease infestation, or severe weather. Some fruit can get taken by wildlife. Yet, for most of us, the reward of fresh fruit is worth all the hard work that goes into growing it.
Unfortunately, most types of fruit, especially the stone fruits, ripen simultaneously within their respective seasons, and are suddenly and briefly too abundant to be consumed while still fresh. Unless shared very efficiently with plenty of friends and neighbors, some of the fruit must be canned, frozen or dried for later consumption. Then, as suddenly as it started, the season for the particular type of fruit is done. There will be no more until next year.
That had never been a problem us, even though some of the fruit trees produce quite a bit. There was one particular summer, about 2004, when we were expecting an unusually abundant crop of unusually big peaches. We got all the jars out and cleaned on Friday afternoon. All the big pots and utensils that we would need for canning were out on the counters. We must have purchased ten pounds of sugar, and even got some pectin for jam.
Early on Saturday morning, we went out to collect the peaches while it was still cool, and found them GONE! It was as if they had never been there. All the work of pruning and pampering the tree was for NOTHING!
Now, I know that when I was a kid, we shared abundance with neighbors. We children were expected to take brown paper grocery bags of produce to neighbors who lacked the trees for particular fruit. For example, I delivered cherries to those who lacked cherry trees. I delivered apricots to the few who lacked apricot trees. Neighbors sometimes stopped me on the road to give bags of fresh produce for my parents or other neighbors.
Also, I know that there was nothing wrong with taking a few fruits from a neighbor’s tree. We often went behind the Charles Residence to get a few oranges when we got out of school. We sometimes got apples from the back yard of the Richmond Residence. Of course, we first asked if we wanted more than a few for a recipe or something. No one really minded because the system was respected, and none of the trees were exploited.
That was a long time ago. By the time I was in high school, we started hearing about fruit trees getting stripped of every last bit of fruit while no one was around. Over the years, it became progressively common. Some neighbors had me cut down fruit trees from their front yards because there was no point in all the maintenance if they could not get fruit from them. It was saddening, wasteful, and so contrary to our formerly idyllic lifestyle.
When it happened to the peach tree that I had taken such good care of in the garden next door, I was furious! What made it even worse is that we knew who did it! The so-called ‘gardener’, who was supposed to ‘maintain’ ONLY the front lawn stopped by the prior evening, just after I checked on the fruit. I sort of wondered why he was there so late, and why he was in back, but gave it no more thought than that.
He later told me that no one wanted the fruit, and that it was just going to fall on the ground and go to waste. Really, I would not have minded if he had taken a few peaches. I would not have minded if he had taken several or even most if he had asked before we got ready to can them. It would have been better for someone or several someones to enjoy them fresh than to can them as surplus.
About a year and a few months or so later, the fig tree in my back yard was stripped by the so-called ‘gardener’ who supposedly ‘maintained’ the landscape next door on the opposite side of where the peach tree lived. There had been no preparation to dry the figs yet, since I had planned to leave them on the tree a bit longer. Also, there was not as much fruit as there was on the peach tree.
The theft of the fruit was not the worst of the problems in this situation. The main problem was that the tree was so severely damaged in the process. I had pruned the tree so meticulously for several years, both for good (late crop) production, and also for clearance above a parking space. I did not mind the slightly elevated canopy; but the guy who stole the fruit without a ladder broke the limbs so that he could get the higher fruit!
They do not come with instructions for their maintenance. Deciduous fruit trees, particularly the stone fruit trees (such as cherry, plum, prune, apricot nectarine and peach) and pomme fruit trees (such as apple and pear), can be procured as easily as nasturtium seed or petunias. Whether bare-root in winter or canned (potted), they very often get planted into gardens where they are expected to produce their fruit as easily as daisies bloom.
Instructions for planting that come with bare root stock are useful for getting those particular trees started, but mention nothing about how even brand new trees need to be pruned after installation, and will need specialized pruning annually every winter thereafter. The same applies to rose, raspberry, blackberry (all varieties), grape, and to a lesser extent, fig, pomegranate, persimmon and several other fruit producing trees, vines and shrubs.
The problem with the stone fruit and pomme fruit trees is that they were bred to produce an unnatural abundance of unnaturally large fruits that are too overwhelming to sustain as they ripen, and too heavy to support. The others are in a similar situation, but are somehow able to continue to produce and generally support their own weight as they get overgrown and congested. Roses deteriorate and succumb to disease as they get congested.
This is why annual winter pruning is so important. Such pruning concentrates resources into fewer but superior fruits, rather than too many inferior fruits. It also limits and contains (closer to the main trunk and limbs) the weight of the fruit, so that limbs are not so likely to break as fruit develops.
These wimpy stems hanging vertically from the weight of the maturing apricots might be able to support the weight of the fruit, but the excessive fruit will be of inferior quality.
Unlike all the fancy and popular Japanese plums and European prunes, wild plum, Prunus americana, is almost never planted intentionally. It is a common understock for the more desirable types, and usually grows as suckers from below graft unions. In fact, it often grows from the roots of plum or prune trees that died or were cut down earlier. They can eventually form thickets.
Well groomed trees can get more than fifteen feet tall and broad. Even diligent pruning can not remove all of the sharp short twigs that make the stems seem thorny. Collectively, the simple and small white flowers bloom very profusely. The thin leaves that emerge after bloom are about two or three inches long. The small and soft red plums are only about an inch wide, with big pits.
Wild plum trees are very resilient, and can can survive in abandoned gardens, but really prefers occasional watering. They will lean away from the shade of larger trees. New trees do not often grow from seed, but if they do, they might be distinctly different from the trees that produced the seed. Some might be hybrids with other plums. Some might produce amber yellow plums.
The fruit may not be as fat and sweet as popular garden varieties of plum, but happens to be excellent for traditional plum jelly, either red or amber.
Without specialized pruning while they are bare and dormant in winter, many deciduous fruit trees would be overburdened by their own fruit next summer. The production of excess fruit can waste resources. The weight can disfigure and break limbs. The trees certainly do not want to get so overworked; but they have been unnaturally bred to produce bigger, better and more abundant fruit.
Proper pruning of dormant fruit trees improves the structural integrity of the limbs, and limits the weight of fruit that will develop on the remaining stems. This might seem to be counterproductive, but it is the only way to keep limbs from breaking or growing so high that the fruit is out of reach. It also concentrates resources into fewer but superior fruit, instead of more fruit of inferior quality.
Dormant fruit tree pruning can not be adequately described in only a few paragraphs. Yet, it is so important and so specialized that anyone wanting to grow fruit trees should learn about it. Each type of tree requires a particular style of pruning. Something they have in common is that the ‘four Ds’, which are ‘Dead, Dying, Diseased and Damaged’ stems, obviously need to be pruned out.
The various stone fruit trees (which are of the genus Prunus) need various degrees of a similar style of pruning. Heavy fruit, like peach and nectarine, necessitate more aggressive pruning than does lighter fruit, like plum and prune. Lighter fruit is easier to support. Some cherry and almond trees may not need to be pruned every year. (Almonds are ‘stones’, and their hulls are the ‘fruit’.)
Flowers of next spring and fruit of next summer will develop on stems that grew last year. These stems need to be pruned short enough to support the fruit that can potentially develop on them. If too long, they will sag from the weight of the fruit. If too short, they will not produce enough fruit. Stems that grow beyond reach can be pruned even more aggressively to stimulate lower growth.
Apple and pear trees also produce on the stems that grew during the previous year, but produce more on short and gnarled spur stems that continue to produce for many years without elongating much. Therefore, the tall vigorous stems that reach upward, particularly from upper limbs, can be cut back very aggressively if necessary. Aggressive but specialized pruning keeps trees sturdy and contained, and also improves the quality of fruit production.