Home Orchards. Slide 1. Greetings everyone!

Transcription

1 Home Orchards Slide 1 Greetings everyone! My name is Dr. Mike Bush and today I will address the topic of Understanding Tree Fruit Horticulture. I have served as an Extension Educator with Washington State University (WSU) since My educational background is primarily pest management with a focus on entomology. In 2004, I was adopted by the Yakima County Master Gardener program as their diagnostician and as their program coordinator. When I first started with WSU, my sole responsibility was to the tree fruit industry along the Yakima Valley. There is no better place to study tree fruits as together with the Columbia Basin and the Wenatchee Valley, the Yakima Valley could be considered the Fruit Basket of the USA as WA State is the nation s number one producer of apples and sweet cherries not to mention a leading producer of pears and soft fruits like peaches, nectarines, plums and apricots. Slide 2 As Master Gardeners here in Washington State, you must ask yourself why grow tree fruit in your backyard when you live the number one deciduous fruit basket in the USA. First of all there is a satisfaction of being your own provider, plus you also know the pesticide history of the produce. Don t forget the advantage of eating a juicy, flavorful tree-ripened product. And certainly fruit trees are fantastic landscape plants that display a beautiful flower bloom in the early spring and sport colorful fruit at harvest. You may also choose to grow antique or unique fruit varieties that are hard to find commercially. For example, I occasionally can peaches but I have a difficult time trying to grow and find the Elberta peaches that hold up well to the rigors of canning better than any other peach or nectarine variety. And finally, as Master Gardeners, we all know that gardening is a wonderful and relaxing hobby! Slide 3 The biggest constraint to growing fruit trees in your backyard throughout the State could be our climate. So the first consideration to address when selecting a fruit tree is how cold does it get in your area during the winter? Excessively cold, freezing temperatures can damage sensitive plant tissues, especially the leaf and flower buds. Normal healthy plant tissues will appear to be creamy white to light green when first cut open. In these pictures, the bud tissues and vascular tissues in the branches are brown and dead. These tissues were killed off by cold winter temperatures and that damage will become very evident in the spring when these buds fail to open up. Page 1 of 15

2 Slide 4 So how cold is too cold for the winter temperatures? This answer varies between tree fruits. Apples are relatively tolerant to cold winter temperatures; after all, apples can be grown as far north as Alaska. Tart (or pie) cherries are also fairly cold tolerant and the leading producer of tart cherries in the US is Michigan. Brrr! It gets rather chilly in Michigan. Peaches and nectarines are the least winter tolerant of the deciduous fruit trees. The leading producers of peaches and nectarines are Georgia and California, but there are some varieties that will do just fine in New Jersey, Michigan and here in Washington. Slide 5 The United States Department of Agriculture has devised a system of climatic zones throughout the US based on average minimum temperature during the winter. This slide shows those zones for the state of Washington. Again, apples and tart cherries are relatively cold tolerant. And they can survive when the average winter temperature dips as low as -30 degrees F. Any area designated in climatic zone 4A or lower is probably too cold for backyard apple trees. Note that there are no zones that get that cold here in the State of Washington, suggesting that we can grow apples and tart cherries nearly anywhere in our state. Pears and plums are generally tolerant to cold weather and can survive up to -20 degrees F. They can be grown in just about everywhere in the state except possibly in the little climatic zone around Republic, WA. Peaches and nectarines will not do well in climatic zones lower than 6A or zones where the average winter temperatures drop to between -5 to -8 degrees F. The two yellow dots mark Yakima and Ellensburg and these areas may be marginal for production of backyard peach and nectarine trees. Slide 6 A second climatic consideration is the length of the growing season in your area. Typically the growing season is that period that runs from the last spring frost through the summer to the first autumn freeze. Spring frosts in April and May can toast the flower and leaf tissues when they are in their most temperature sensitive state. The leaves and flowers in this picture in the lower left corner are completely encased in ice - that sheath can actually protect these tissues to some degree. The blossoms on the lower right have been killed by a spring frost. Chances are the most delicate reproductive plant organs have been damaged and most of these flowers will not set fruit. Apricots tend to be the most susceptible tree fruit to late spring frosts, as these trees tend to be the first of the tree fruits to bloom in the spring. In Selah, WA, I m used to getting a good crop of apricots once every three years. Occasionally in the Yakima Valley we get Halloween freezes and these freezes can jeopardize the harvest of late maturing fruits like the Fuji or Pink Lady apples. If these freezes set in before the fruit trees drop their leaves, we might encounter some problems with return vigor in the next season. Page 2 of 15

3 Slide 7 How long does the growing season need to be for fruit trees varies from fruit to fruit and can be a constraint to which fruit tree you plant in your backyard here in Washington State. As a general rule of thumb, soft fruit trees (particularly peaches & nectarines) need at least 150 frost-free days. This slide provides a rough estimate of the growing season length in Washington. Roughly half the state, from the Cascades east, are unsuitable for most peach and nectarine varieties. Again, notice the two red dots marking Yakima and Ellensburg. These locations are marginal, but Ellensburg typically does not have a suitably long growing season for soft fruits. Slide 8 So, why is Washington State the leading producer of apples in the US? Because we have areas in the state that provide the ideal mix of warm sunny days, cool autumn nights, and dry, desert-like areas that do have plenty of water. Ideally fruit trees need frostfree days. In this map generated by the Washington State Statistical Survey, areas of commercial apple production are highlighted in the red dots. It is not coincidental that these areas, stippled with red dots, fall within zones shown in the figure to the right that receive between 120 to 150 frost-free days. Slide 9 So clearly, our climatic frost/freeze zones can determine which fruits we can plant in our backyards here in Washington. Homeowners can control a number of factors that allow them to avoid or minimize this frost/freeze injury and increase the number of tree fruits that they can plant. The first thing homeowners can do is plant fruit trees that are winter tolerant and better suited to our climate. For example, remember they can plant apple varieties in Alaska, so surely we can plant those same varieties in the colder parts of our own state. Within your own home landscape, there are areas that you might want to avoid when planting fruit trees. Do not plant fruit trees in the lowest spots or the frost pockets in your home landscape where cold air can collect during the winter or early spring. Remember like molasses, cold air tends to flow downhill and will collect in those lowest pockets in your back yard. In the picture to the left, the red dots mark the worst places in this home landscape to plant fruit trees in the home, whereas the blue dots marks the best spots to plant the tree. Remember I do manage to grow apricots in Selah despite the fact that the climate is not appropriate for most apricot varieties. Slide 10 Well, okay! You could take my recommendation for good air drainage a bit too far. You will also want to avoid those areas within your landscape that are excessively windy. For example, if your landscape trees are all leaning in one direction or there is a wind-driven Page 3 of 15

4 energy generator in your area, don t plant your fruit trees there. Excessive wind can threaten tree establishment, but more importantly, fruit that blows in the wind is likely to bounce or rub against adjacent fruits or limbs and may display unsightly scabs or bruises. Light-colored fruit like Rainier cherries are extremely susceptible to this type of damage. Slide 11 Commercial orchardists combat frost and freeze damage by providing their trees with a little extra heat. They can do this through a number of strategies such as orchard heaters or wind machines that blow the rising warm air back into the orchard. These strategies may not be feasible for the backyard fruit tree but creative homeowners have been known to do things such as string heat-generating holiday lights in their fruit trees or to place barrels of water next to their fruit trees that capture the sunlight during the day and release heat during the night. Some homeowners may elect to enclose their fruit trees in heated structures. Now the picture on the right is actually a picture taken at the WSU-Prosser research site and this apparatus was meant to measure gas exchange during tree respiration. Nevertheless, it is a strategy that here in Yakima news media likes to hound me about as we have a couple here in Yakima who ve had palm trees in their front yard for about 10 years now. Every winter they build a wooden frame around the tree and enclose it in translucent plastic just so they can claim that they do live in the Palm Springs of Washington State. Slide 12 One unlikely source of heat that orchardists and homeowners alike can use to combat winter injury is freezing water. That s right; as water turns to ice it releases a minute amount of heat! This heat can provide the fruit tree with a few precious degrees of protection against the cold nighttime temperatures in the early spring. Orchardists may chose to use overhead sprinklers to distribute water throughout the canopy of the trees while homeowners may chose to use under-tree sprinklers for a similar effect. Again as the water freezes, it releases heat. Plus, the ice serves to insulate the buds that it covers. A couple drawbacks to this approach. Your water flow must be continuous during the freezing period as it is the process of freezing that releases the heat; so plugged nozzles or broken water mains can be a disaster to the process. Also, excessive ice buildup will add weight to the tree limbs and sometimes that weight can actually break limbs and scaffolds. Slide 13 One other form of winter injury to watch out for is southwest winter injury to the trunk of the tree. This mostly applies to young fruit trees, transplants, and smooth-barked ornamental trees. Basically, in the winter after the tree has lost all its leaves, it is most susceptible to trunk sunburn. The sun s rays hit the southwest side of the tree, warming the surface temperature of trunk well above ambient temperatures. Then in the evening when the sun Page 4 of 15

5 goes down, both the ambient air temperature and the temperature of the bark can quickly drop, damaging both the tree bark and vascular tissues as that drop reaches 40 or 50 degrees in one hour s time. This effect can be exacerbated by a snow groundcover that reflects even more energy on the surface of the fruit tree s trunk. All this causes cell and tissue death, bark cracking and sloughing, and leaves points of disease infection in the tree that may not become evident until years later. Orchardists typically paint or spray the southwest side of newly planted fruit trees with a dilute solution of white latex paint so that the sun s rays are actually reflected off the tree bark, preventing surface bark heating. This strategy is one that homeowners should consider as well. Slide 14 Do not be dismayed by this presentation if you happen to live in the colder areas of Washington State where the fruit tree you desire is not recommended. Homeowners can take advantage of artificially created micro- or mesoclimates. This is a fig tree that has survived beside the Yakima County Courthouse for over a decade now. Normally fig trees cannot be grown in the colder climatic zones of Eastern Washington. This tree is planted in a little alcove on the southwest side of the building that captures the heat that radiates from the adjacent parking area. The soil underneath the tree is covered with good-sized rocks that also capture the sun s warmth during the day and releases the heat at night. Every third year or so, this plant suffers from dieback caused by freezing temperatures but the tree s crown and root system is able to weather the cold temperatures and recover during the next growing season. Basic needs for a fruit tree are: warm days, cool nights, full sun exposure, and a nice sandy loam that is at least 4 feet deep, and regular irrigation. Do not overlook the regular irrigation need. Even on the west side of the state, summer temperature, climates, and droughts can adversely stress and reduce the vigor of fruit trees on both sides of the mountain. Slide 15 At this point, you should have a pretty good idea of which tree fruit you can grow. Now, comes the fun part, choosing between the thousands of fruit varieties out there. You might want to shop around before making your final selection. Many homeowners will choose their fruit and fruit varieties based on appearance and on fruit flavor. Do you like green, yellow, red or blush-colored apples? My favorite apple variety is Honeycrisp, shown in the picture furthest to the left. It has a blotchy red color with a yellowish-green background, but it has a very unique honey sweet flavor and sort of fractures when you bite into it. On the other hand, you might want to try one of those new doughnut-shaped white-fleshed peaches or perhaps settle on a great canning variety of peach like Golden Elberta. Perhaps you want to stick with a deep red-colored Bing or grow the unique yellow-fleshed Rainier cherry variety. You might even get adventurous and try some of those interspecific fruit varieties like the pluots which are plums crossed by apricots, or the pecotums - peach by apricot by plum. The word on these fruits is that they need a long Page 5 of 15

6 growing season and are not so winter tolerant. Anyway, these choices are nearly endless. Slide 16 There are other considerations that need to be addressed before settling on a variety of fruit tree for your backyard. One major consideration is fruit maturity timing or when you need to harvest the fruit. In the case of apples, there are some varieties of apples that tend to mature and are ready to harvest by early to mid-august here in Washington State. Some early maturing varieties include Gingergold, Akane, and Lodi. Most apple varieties mature in late August to mid September. Macintosh, Gala, Honeycrisp apples fall into this harvest frame. Finally, there are some varieties that take the entire growing season to produce a mature fruit. Granny Smith Fuji and the world renowned Washington Red and Golden Delicious apples take the entire growing season. Oh, and then there are some of those unique colored Cripps Pink (AKA Pink Lady) apples that are harvested as late as early to mid November. For those Master Gardeners with a shorter growing season, the early apple varieties are more appropriate. For those of you who will plant more than one apple variety, you might want to consider apple varieties that mature at different times during the season so you don t get overwhelmed with harvest. Slide 17 Another important consideration is disease resistance, especially if you live on the west side of the Cascades where precipitation and leaf moisture can create more frequent problems with fruit diseases. Even on the east side of the state, we frequently have problems with diseases such powdery mildew in apples, cherries and peaches. Powdery mildew is a disease pathogen that only needs high relative humidity to thrive. Powdery mildew causes leaves to turn white and die prematurely. On fruit it can lead to a surface russeting. If powdery mildew is a problem in your area, you might want to select a red apple variety like Liberty or Enterprise that have a natural resistance to these diseases. On the west side of the state, plant diseases like apple scab, fireblight can make the growing of apples and pears challenging. If these plant diseases are common to your area, you might want to select a resistant fruit variety like the Chehalis, a green apple variety with a Washington name, or a pear variety like Blake s Pride or Shenandoah. Slide 18 Most nurseries supply fruit trees that are actually two plants grafted together. The top portion of the fruit tree, known as the scion, is the portion of the fruit tree that is above the ground and bears the leaf canopy and the fruit variety. The bottom portion of the fruit tree is known as the rootstock. It includes the root system and the trunk collar at the base of the tree that extends a few inches above the soil line. The tree rootstock often provides overall fruit trees with key characteristics such as soil anchorage, soil disease resistance, soil moisture tolerance, or drought tolerance, and precocity, or the ability to bear fruit earlier in the tree s growth. Page 6 of 15

7 Slide 19 But by far the most important function of fruit rootstocks is tree dwarfing. A standard apple tree will grow to heights of 25 to 30 feet, raising the height of the apple canopy far beyond what can be comfortably reached from the ground during harvest. This necessitates the use (sometimes improper & unsafe use like what you see in the upper right-hand picture) of ladders to not only harvest the fruit, but to perform other tree fruit management chores like pesticide applications. And of course, you know the biggest and most colorful apples will be near the top of the fruit tree. Apple plants grafted on dwarfing rootstocks are much more manageable and come highly recommended for backyard fruit trees. Apples grafted on the most common dwarfing rootstocks of M9 and M26 can be maintained at a tree height of 20 to 30% the size of a standard apple tree. In the bottom right picture, a researcher is examining the fruit canopy on a 50-year-old tree that is no more than 7 feet tall, whereas the apple tree behind him is about 18 to 20 feet tall. Slide 20 When you are buying a tree, remember you are buying two varieties; you are buying what you are going to eat, and what it is grafted on, the rootstock. I am going to show you two trees that are comparatively the same age. This tree was grafted on what you call an M9, and most of the fruit can be picked from the ground. It is on a dwarfed rootstock. You can have a whole step ladder of bottom varieties. For instance, if this one was Gala, this one could actually be only up to six foot tall (if it was on an M27). Where if it was on a bottom variety that was an M111, it may be a tree that is actually fifteen - twenty feet tall. So, you as a home gardener have got to determine how big you want that variety to be. We are going to show you some espalier. This is particularly important when you are going to do espalier, because picking the right bottom variety can contain it in a certain space. Otherwise, you are fighting a tree trying to outgrow the space because genetically it was meant to be a lot bigger. So, this one is with a bottom variety that stays pretty small. This is an M9. Let s show you one that is a little bit bigger. This is a tree that is on a bigger rootstock. This happens to be for our Skagit Valley M26, which gives you a fairly good size tree, up to twelve feet tall. It is bigger and about the same age as the one we just saw. You can get one even bigger. If you put them on seedling stock, then they can get up to twice as big as the one you just saw. So, decide how big you want to get and what you want to do with the fruit tree. Slide 21 Quite recently dwarfing rootstocks have become available for homeowners who want to plant sweet cherries in their backyards. The most popular dwarfing rootstocks are known as the Gisela series. Cherry trees on Gisela rootstock can be 40 to 60% the size of a standard cherry tree. That equates to a 12 to 16 foot tree versus an oversized 20 to 30 foot tree, where of course the best cherries are nearly inaccessible to homeowners. At this time, there are no popular dwarfing rootstocks for peaches, nectarines, pears and other Page 7 of 15

8 fruit trees, but keep your eyes open for these dwarfing rootstocks are in the near future. So, make your gardening life simple; always select fruit trees on dwarfing rootstocks when these rootstocks are available. Slide 22 Another important consideration for backyard fruit trees is pollination requirements. All deciduous fruit trees need flower pollination to set fruit. Pollination is defined as the transfer of pollen from one flower to another flower. The fruit tree that donates the pollen to the flowers on another tree is called the pollenizer. Frequently the pollen is transferred from the pollenizer to the receptor tree by wind, blowing rain or by the industrious honeybee, orchard bees, flies or other pollinator insects. Sometimes fruit trees will set fruit even when the flowers are not properly pollinated. Often these undersized fruit (see the yellowish fruit in the picture on the left) will fall off the tree during June drop. When these fruits are cut open they often lack the full complement of 10 apple seeds in their core. Slide 23 Some fruit tree varieties are self-fruitful. That means one flower can pollinate another flower on the same fruit tree. Tart cherries, most plums and some sweet cherries are selffruitful and pose no additional challenge to the homeowner. A number of fruit tree varieties are self-unfruitful. That means the flower must be pollinated by pollen arising from another fruit variety. Apples, pears and most sweet cherries are self-unfruitful. That means homeowners need to select and plant at least two varieties of apple trees (or pear or sweet cherry) to serve as pollenizers for each other. Slide 24 There are a couple solutions to this problem of self-unfruitful tree varieties. First, homeowners may consider planting two compatible varieties of fruit trees. Typically, nurseries will provide their clients with pollination charts to help select compatible varieties. For example, in this cherry pollination chart one can see Bing cherry cannot pollinate another Bing cherry flower as Bing is self-unfruitful. However, Rainier cherries can serve as a compatible pollenizer variety for Bing and vice versa, Bing serves as a pollenizer for Rainier cherries. One alternative approach is to plant self-unfruitful varieties in your backyard and rely on neighboring fruit trees to pollinate your tree. In the upper right, there are four backyard Akane apple trees that are fortunate to be able to rely on the pollen donated by an adjacent Gala apple orchard. Slide 25 Another fun solution is to graft multiple fruit varieties on a single tree. In this picture a backyard pear tree has six different varieties of pears grafted onto the same tree. Lately, I have seen sweet cherry trees sold by local nurseries that have been grafted to bear branches of Bing cherry and Rainier cherry varieties on the same tree. Another solution to Page 8 of 15

9 poor crop set on a self unfertile variety of fruit trees is to drive around the neighborhood in search of similar fruit trees that bloom at the same time as your tree and collect blossom bouquets to place in a pail of water that you can hang from your own fruit tree. Then just allow the honeybees to do their role and transfer the pollen between the bouquets and the fruit tree flowers. And of course, I am assuming that you seek permission before you cut the bouquets from your neighbor s fruit trees. Slide 26 Usually this time of year (this is in early September, usually from August to mid- September) we can bud trees to change varieties. What we do is come up to the tree, this is a variety we want to take wood from. So we ll look for a good piece of scion wood (grafting wood), this is a one year shoot that shot up this year. So, we will take this one off like this. I then remove the leaves and this is what I am going to graft onto, this particular variety. This is a budding knife and I m going to make a slice into my stock. This is a bottom variety and I am going to change to this top variety. Look at a bud right here and try and try to make the same type of cut. See how I am cutting and pulling sideways. Hopefully this will not cut myself. I pull this out, there s the bud right here, I try not to handle this part here with my hands, because your body oils act like a herbicide. This area right here is a cambium layer that will produce cells that will mend with these cells right here. So, I try and match them up, put it right in the middle like that. Then I take my piece of tape (this is non-sticky tape), acts like a greenhouse. I start at the bottom. This is called budding. I just start wrapping the bud completely up at this time of year. Makes a little greenhouse. Then I can just tie it up on itself. And it is done. That s budding Now in about five weeks I ll come and I ll cut the back of the tape off; it should be mended by then. That will set all winter long. If you forget to cut the tape off, the graft can take but the bud might rot in there. Next spring as things are just starting to grow, you don t cut it off then. I will cut this off right above this bud, and that bud will grow into a whole new tree. And, that is how it is done in nurseries. Now if I want a different variety, this is variety A, I could put variety B on this stock, and variety C on this stock. This would be really important for something like plums. Because it is very difficult to eat all plums from one tree in one sitting because there are so many on there. So, if you get different varieties of plums in your yard, maybe one variety that would ripen at the end of July, then one in the middle of August, and one at the end of the first of September, and maybe even one a little later than that. You would be eating plums throughout the whole season. They would pollenize each other and give you plums throughout the season, and not so many at one time. Here is a plum tree, a young tree that is full of plums and all the same variety. If you would have grafted this one to a yellow variety that is a little bit earlier, and one that is a little bit later they would pollenize each other and you would have plums for a longer period time throughout the season. Page 9 of 15

10 Slide 27 Break Time Slide 28 After choosing a fruit tree and the variety that you want to grow in your backyard, the next step is to plan and select a good site within your home landscape to plant that tree. Be sure to consider space needs of your tree. Ask yourself how tall the fruit tree may get; where in the landscape the tree will get full sun, ample water and have good air drainage. Once a site is selected planting the fruit tree is pretty straight forward. Dig a shallow but wide hole that can accommodate the tree s root system. Most orchardists plant fruit trees bareroot and it would be prudent to remove the burlap and tease the roots apart if you plant it in the fashion as in this picture. It is very important to make sure that the graft union between the scion wood and the rootstock remains several inches above the soil surface after the soil is tapped down. If that soil covers the graft union, the scion wood will produce roots and the dwarfing effect of your rootstock will be lost. Be sure to provide the newly planted fruit tree with ample water, but fertilizer is rarely needed for fruit tree transplants in backyard soils here in Washington. Slide 29 Fruit tree irrigation is rather important even for backyard trees on the western side of Washington state. A general rule of thumb is that fruit trees need a good root soaking every 7 to 15 days. Remember fruit trees tend to root deeper than grass roots in your lawn. Newly transplanted fruit trees with poorly developed root systems should be babied and watered on the shorter side of the above range. Likewise, fruit trees that are exposed to the hot summer climate will require more frequent waterings than in the early spring or late fall when the daytime temperatures cool. Beware! Fruit trees that are overwatered will show the same wilt symptoms as trees that are underwatered. It may be prudent to dig down to the root system of your fruit tree and check the soil moisture in the soil at the tree s root zone if your tree shows signs of water stress. Slide 30 It is seldom necessary to fertilize young fruit trees planted in Washington home landscapes. Of all the nutrients, nitrogen is often the only nutrient ever needed. A visual assessment of the fruit tree s canopy is the best indicator as to whether a nitrogen fertilizer is needed or not. If the new year s shoot growth on a mature, full-sized tree is between 12 and 18 inches long, no nitrogen is warranted. If you have your tree on a dwarfing rootstock, then 4 to 6 inches of shoot growth is adequate. Also, if your fruit tree produces leaves that are light in color (green or yellow in color like in the top image), you may have a nitrogen-deficient tree. When nitrogen fertilizers are necessary, the amount of fertilizer added depends on the tree age and the product used. As a general rule of thumb, apply no more than 1 pound of actual nitrogen per year to a mature fruit tree. That fertilizer can Page 10 of 15

11 be scattered along the soil surface beneath the fruit tree in autumn or better yet in the early spring to avoid any nitrogen runoff. Remember too much nitrogen can create problems in fruit trees as well as too little nitrogen. Too much nitrogen will stimulate shoot growth at the expense of fruit growth and delay the maturity of the fruit itself. Boron is the only micronutrient I have seen deficient in home orchards. Fruit trees deficient in boron tend to have rather unusual shoot growth with abnormally small leaves. Any unusual tree growth like this should be brought to the Master Gardener Clinic for proper diagnosis. Slide 31 Hello. One of the most important things in growing home fruit is having a good fertility program. In western Washington, we have a lot of growth and they grow very well. But that s because we have a lot of nitrogen in our soil because of a high organic matter. Which as the soils warm up it releases more of the nitrogen throughout the season. Particularly if your soil holds a lot of water, you ll get a lot of growth. And a lot of people think, Well I have way too much growth so I have enough fertilizer, but that is not always the case. There are things like potassium, magnesium, and calcium tend to be depleted in our soils over a period of time and we are more like back east than we are like in the more arid climate of eastern Washington. So, for a home gardener probably as a general rule of thumb I do recommend that they might lime their soil about every four years and use a dolomitic lime, something with magnesium in it, and then use a potassium, a complete fertilizer like would be fifty percent of fifty pounds of potassium per hundred pound sack. The first number is nitrogen, the second number is phosphorus, and the third number is potassium. So, add potassium, magnesium, calcium, but to do an accurate job, if you have a big home orchard, I would recommend that you do a soil test or a soil analysis. And we do this every two to three years in the commercial end of it. One of the things you want to do is get a snapshot of what the tree is doing so you want to probably do a probe around the roots to see what it s taking up. So we will run a probe down, sometimes this is a little bit hard to do and it is getting dry at this time of year, but we put it right around 18 inches, pull it up and then we would take this soil here, take it off, and we would run it into a bucket, and we would go around and do it in several spots within the orchard, maybe doing up to fifteen of these samples. Mix them in the bucket and send the soil sample in. Remember this is just a snapshot and so if you just have one probe it is not very high percentage of what you are trying test. So, you are trying to get an idea of what you have. And from there, in our handbook, it gives recommendations of what levels you should be at. You can talk to a home garden fertilizer shop, one of your farm shops in there should be able to tell you, or one of your county agents, how much fertilizer you need to be adding to your fruit trees. Slide 32 There are dozens of fruit tree training systems available to homeowners, but the key to most of these systems in to maximize sunlight interception by the tree and allow that light Page 11 of 15

12 to reach the tree s fruiting zone. Often homeowners will try to maintain that fruiting zone within reaching distance of the ground so they do not have to use ladders to harvest the fruit. Periodically throughout the year, homeowners should inspect their fruit trees and when possible prune out any dead, diseased or damaged branches or wood on that tree. It may be necessary to manage the angle of the main branches coming off the trunk of the tree, especially for cherries, pears and some apple varieties that have this tendency to grow towards the sky and set narrow, weak, fruit-bearing angles. Early in the tree s development producers and homeowners may want to spread the angle of those branches so the branches spend more energy setting fruit and less energy growing upright. Ideally, the strongest crotch angle is between degrees. Take caution not to set too large an angle; that can cause lateral shoots to become overly vigorous and grow upright rather than setting the fruit themselves. Slide 33 In general, newly-planted trees require little pruning although homeowners might want to balance the aboveground tree growth so that it matches the biomass found in the root zone. As fruit trees mature, more pruning is advised to maintain a good fruiting zone. Mature fruit trees will require moderate pruning every year. Basically this pruning involves removing upright shoots, thinning out shoots and branches towards the end of the major branches, and occasionally removing whole limbs from the top of the tree to allow light to penetrate the center or lower limbs of the tree. Fruit trees can be trained to an open center system or a central leader system, as shown in the bottom left corner, or a number of other training systems. While pruning can be done anytime during the season, the best time to prune is when the trees are in the late dormant season to early spring before the buds start to swell, which falls between March and early April. Do not prune when excessively cold temperatures are in the forecast. During the growing season, avoid pruning when the canopy is wet or when rain is in the forecast. Blowing rain and moisture can spread diseases like wood rots, fireblight, and tree cankers from tree to tree and allow them to infect fresh pruning cuts. Remember that the goal of tree pruning is to enhance the amount of light, air and any pesticide applications to penetrate the tree s canopy to reach the fruiting zone. Slide 34 Remember, light is what leaves need to produce sugars. They take carbon dioxide and water in the leaves and produce sugars. When the light intensity goes down, you see leaves starting to die, you start seeing less color in fruit, and next year s crop can actually be affected - because if there is not enough light on the bud, they will die too. So, you need to have light in the interior part of the tree. Where you saw in the espalier, everything was well exposed. Sometimes you can come in, particularly when you see a lot of vigor in here, and make thinning-type cuts; cut that back to the point origin. I ll make a cut here; you see I m exposing these to light here. I ll make a cut here; I m thinning it out to the point of origin. Thin here, and here, and here, and as I thin more out you can see I m letting light Page 12 of 15

13 channels in as well. Now, look up underneath there and you see some of that green fruit? That s not getting enough sunlight and they are getting a bit weak. So, you can make some key cuts in there, sometimes even moving branches around to let some light in. Actually at dormant pruning, maybe few more light channels, what we call laterally so you could walk up into it, would have helped get more fruit color into that. But you can make some cuts, or strip some leaves now to expose that fruit to light. Slide 35 One consideration to keep in mind when training and pruning fruit trees is the fruiting habit of the tree; i.e., where does the fruit hang in the tree. Many varieties of apples and cherries as well as pears, apricots and some plums will set their fruit on long-lived spurs that are the short stubby branches shown in the uppermost diagram and on the photo of the cherry branch on the left. Of course growers and homeowners do not want to prune these valuable spurs off, especially the ones low in the tree canopy, but homeowners will want to ensure that sunlight penetrates the tree canopy to reach these fruiting spurs and maintain spur productivity. Most varieties of peaches and nectarines set their fruit on shoots or short branches on the first year wood only; i.e., only on branches and shoots that formed during the last growing season. So homeowners can really prune back those peach and nectarine trees to keep renewing new fruit growth and maintain the fruit close to the ground. Just to make pruning and training even more challenging, many varieties of apples, pears and sweet cherries will set fruit both on spurs and on shoots. So keeping the fruiting zone close to the ground and assuring adequate sunlight penetration are critical to backyard fruit tree productivity. Slide 36 In general, fruit trees tend to set far too many fruit, especially when they survive the cold winter temperatures and avoid any spring frosts. This can lead to big clusters of small, undersized fruit. Often commercial orchardists thin off fruit blossoms during bloom or thin off small fruitlets early in the growing season. Homeowners should thin their fruit trees to reduce fruit bruising, excessive crop load, and improve the quality and size of their fruit. Apple trees tend to set clusters of five or six flowers that develop into apples. The central flower in each cluster is called the king bloom and when pollinated, that flower will produce the biggest fruit. Homeowners should thin each cluster to one flower or one fruitlet; ideally to that king bloom or the fruitlet in the middle of the cluster. Peaches, nectarines and apricots should be thinned as blossoms or as fruitlets as well. Typically, you will want to thin fruitlets so they are the width of your fist apart. In general the earlier in the season you thin, the bigger the fruit will be by harvest. However, you might want to delay fruit thinning until after the threat of those fruit-killing frosts are over. Fruit thinning will improve fruit size and fruit quality. Page 13 of 15

14 Slide 37 The best way to tell when to harvest your apple, peach, cherry is to taste it. As these fruit ripen, they convert starch in their tissues to sugar, so this is why tree-ripened soft fruit are so much sweeter than fruit that must harvested, then shipped to market before they are fully ripe. Because harvest/maturity times can vary between fruit varieties and geographic locations, it may be helpful to record the harvest dates of your fruit trees on a yearly basis so you can better anticipate and plan your harvest. Fruit color may be another good indication of maturity; for example, the base color of peaches and nectarines tends to go from green to yellow as they mature. However, color change is not always the best indicator of maturity, as Red Delicious apples tend to color up long before they are ripe or mature. There are some exceptions to the rules above. Winter pears (like Comice and Bosc but not the Bartlett pears) will not ripen properly on the tree. They need to be harvested when they begin to soften, then chilled for 2-6 weeks, then allowed to warm and ripen at room temperature. While the above fruits will continue to ripen after they are harvested, cherries and Asian pears will not ripen further after they are harvested. So do not harvest these fruits until after they have passed your taste and color tests! Slide 38 Now, if you want to ship or store some of your homegrown fruit, you probably should harvest it before it is fully mature. Fully ripened fruit does not store well. Then to preserve them longer, you will need to chill or refrigerate the fruit as soon as possible after you harvest it, thus delaying the fruit ripening process. Also remember, do not store bruised or punctured fruit as these fruits are most prone to storage rots and molds and will not store well. And remember, it only takes one bad apple to spoil the batch! Slide 39 Now since I do live in the temperate fruit basket of the US here in the Yakima Valley, I would be remiss if I did not warn this audience that there are some very good reasons why homeowners should not grow fruit trees in their backyards. Apples, pears and cherries have some serious pests that will infest the fruit if homeowners do not properly manage these pests. I will talk about codling moth, cherry fruit fly and apple maggot in another session of this Master Gardener training. It is extremely difficult if not impossible to manage these pests without frequent and well-timed pesticide applications. These pests in turn can build up in high numbers in neglected fruit trees and spread to adjacent fruit trees in neighbors backyards. If you live in fruit producing areas of the state, these pests can and will invade commercial orchard blocks and create pest management nightmares for the orchardists that often necessitate further pesticide applications. Page 14 of 15

15 Slide 40 One of our biggest problems in western Washington is apple scab. You know the best time to control apple scab is just what we call at green tip tree, just as the tree is staring to grow, that is when the scab infects. Now, once they infect, here s a leaf, you can see the little different infections caused by that apple scab. And as you go down here a little further, here s a fruit that has some of that infection. And here is a fruit that has some of that infection. Now even with a program that you have, if you don t hit those early sprays you can miss it. Usually you want to hit them just at when you have about a quarter inch green tip growing and just the buds are just starting to grow. And If you don t, you get infections and they continue to proliferate through the rest of the season. Now we have a little bit of complex here. You can see the tip of this branch here also has powdery mildew and those early sprays will also help, and aid, and take care of this. Now this tree right here is actually not too bad. This is actually a fairly scab susceptible variety but you know if you look at the fruit, you can go through it when you are hand thinning, and you can pull off the infected ones, and actually probably work your way through it. The amount of scab on this tree is really quite acceptable and the fruit is quite acceptable. We had some early season control, but again, this year we also had a lot of rain through the rest of the summer. And when we get primary infections, you get them spreading throughout the season. Now days like this you don t get any apple scab spreading but it is important to do a very good job early in the season, and you have to put very few light sprays on and most of the apples have little or very little contact with pesticides by doing it early in the season. Slide 41 So here are the take-home messages that I hope Master Gardeners will adopt and disseminate to their local communities. One: nothing is sweeter than a tree-ripened peach, nectarine, apricot or plum from your own backyard fruit tree. I grow apricots and plums at my home residence in Selah, WA and know this fact from personal experience. When you select a fruit tree, be sure to purchase fruit trees on dwarfing rootstock. The cherry tree in the lower left lower picture is nearly 30 feet tall and you know where the best fruit is located in this tree, but can you reach that fruit? Dwarf fruit trees are much easier to care for and do not require ladder work. Also, do not plant a whole bunch of fruit trees at once. Take it slowly; learn and observe the normal growth habits and management strategies for each fruit tree. And don t be surprised if one tree will provide all the fruit you and your family need. Once upon a time, my spouse loved apricots but after few years, she now groans whenever I try to create a new way to serve apricots to her. Finally, remember to relax and have fun with your backyard fruit tree. Page 15 of 15