Planning a Fruit and Nut Orchard: Considerations for Landscape Design

2. OBJECTIVESThe student will be able to… • Plan a landscape suited to the local climate, including two fruit crops and one nut species.

3. OBJECTIVESThe student will be able to… • Select an area suitable for an orchard and justifythe choice. Explain five important considerations in tree species and cultivar selection. Identify a dwarf, semi-dwarf, and standard sizefruit tree. Draw an espaliered tree in two forms. Distinguish between the central leader, modified central leader, and vase tree forms. List five possible causes for a fruit tree’sfailure to produce fruit.

4. SITE SELECTION • Tree crops are raised for their edible fruits or seeds. • Most fall into the designations of fruits or nuts. • We tend to associate fruit with sweet. • The avocado & olive grow on trees and are not sweet. • Classified as fruits in horticulture. • A property may have several possible sites for planting fruit and nut trees. • With species and number of trees determined bya variety of factors.

5. SITE SELECTIONClimate • Minimum winter & average summer temperature and day length will determine species & cultivars. • Avocado and citrus, are semitropical and will tolerate temperatures only to the mid -20 deg F. • Others, like the sour cherry are adapted to climates with widely varying winter/summer temperatures. • Need a cool winter period or will fail to produce fruit or die. • Unexpected spring frosts in temperate areas can also cause problems and summer temperatureand length can also affect ability to grow somefruit trees successfully.

6. SITE SELECTIONProperty Size • Size of the property will determine how many fruit and nut trees can be raised. • Owners of small properties frequently use fruit/nut treesin the landscaped areas in lieu of ornamental trees. • A solution with most fruit trees is to use dwarf cultivars that grow only about 8 feet high. • No nut trees are available in dwarf form.

7. SITE SELECTIONExpected Maintenance Time • Some species have few pests/disease problems. • Others, like the apple, will require spraying everytwo weeks in addition to yearly pruning & fertilization. • The considerable amount of time devoted to maintenance should be taken into consideration.

8. SITE SELECTION Soil Drainage • Water must drain away rapidly to allow air to penetrate to the roots. • If roots are in soggy soil for an appreciable period,the tree will die. • Stone fruits (with a single, hard pit such as cherry, plum, peach & nectarine) are the most susceptible to poor drainage.

9. SITE SELECTIONAmount of Sunlight • Fruit trees should have as much sun as possibleto bear heavily and ripen their crops. • Six hours of direct sun per day is considered minimum. • A sunny spot is also desirable for nut trees and will speed their growth considerably. • Not as essential as for fruit trees.

10. SITE SELECTION Land Slope and Exposure • Situating fruit/nut trees on the upper part of a slope partially protects against frost injury. • Unless it is unavoidable, tree crops should not beplanted in a low spot or at the bottom of a slope. • Flat land is preferable to those areas. • Direction in which the slope should ideally face will depend on the weather conditions in the area. • South-facing slopes warm earlier in the spring, and treewill start growth sooner—susceptible to late spring frosts. • A north-facing slope is suggested in climate areaswith spring frost problems.

11. TREE CROPS IN THE LANDSCAPE • How fruit/nut trees are incorporated in the landscape will depend unique features of the property, but the following suggestions can aid in planning. • Substitute nut trees for deciduous shade trees. • Large nut trees work well as substitutes for shade trees. • Large fruit trees also make handsome shade trees. • If spraying is a necessary part of the maintenance program, the job will be harder with a large tree.

12. TREE CROPS IN THE LANDSCAPE Figure 9-1 Fruit trees used as a screen in a landscape. Drawing by Bethany Layport. • Use dwarf trees as a screen. • Three or more dwarf trees planted about 6 to 8 feet apart will eventually grow to form a screen. • Staggering in two rows will create the screen effect faster without crowding the trees.

13. TREE CROPS IN THE LANDSCAPE • Use dwarf fruit trees as patio trees. • Fruit trees are very ornamental, with lovely spring blossoms and heavy sets of ripe fruit. • Semi-dwarfs should be planted if shade is desired.

14. TREE CROPS IN THE LANDSCAPE The tree will still bear a worthwhile amount of fruit, although probably not asmuch as it would growingin a normal form. Figure 9-2 Espaliered pear tree. Author Photo. • Espalier fruit trees. • The flat-training methodcalled espalier can fitseveral dwarf fruit treesinto the smallest yard.

15. TREE SELECTION • To avoid failure, choosing a proper cultivar is very important in fruit & nut growing. • Read nursery catalog descriptions & Cooperative Extension Service publications for information. • Unless you live near a nursery specializing in fruit & nut trees, the best selection is available from mail-order nurseries. • Several firms specialize exclusively in fruits and nuts.

16. TREE SELECTION Winter Hardiness/Fruit Maturity Period • Some fruit cultivars are bred for growing in the South, others of the same species are bredfor the North. • Cultivars bred for cold climates ripen more quickly than those bred for warm climates where the summer is longer. • Choose a cultivar that will mature and ripen within the limitations of the frost-free growing season. • Fruits advertised as maturing extremely early in the season will often be inferior in quality to later-maturing cultivars.

17. TREE SELECTION Disease Resistance • Selecting disease-resistant cultivars can eliminate much of the labor of spraying against fungus- and bacterium-caused diseases. • Apple varieties are available that are resistant to scab, fire blight, and cedar rust. • Chinese chestnuts are immune to chestnut blight • The American chestnut is so susceptible that onlya few trees are alive in the United States today.

18. TREE SELECTION Fruit Appearance/Use • Size, coloring & shape are included in appearance. • Many gardeners prefer yellow over red apples, for example, or a cultivar that produces mammoth fruits. • But appearance should not be allowed to outweigh the important factors of hardiness, disease resistance, maturity period, and yield. • Some fruit cultivars are primarily for fresh eating. • Others (originally bred for commercial orchard use) are best for drying or canning. • Any fruit bred for processing can be eaten fresh, but quality may be poorer than that of a fresh-eating cultivar.

19. TREE SELECTION Pollination Requirements • Many fruits and nuts require cross-pollination with another cultivar. • With nuts, a tree of the opposite sex to bear a crop. • Many homeowners have grown healthy trees for years without a crop. • Due to failure to recognize pollination requirements.

20. DWARF FRUIT TREES • Most fruit trees come in three sizes: • Standard trees grow to normal size for the species. • A standard apple tree can grow 30 feet across & as wide. • Semi-dwarf trees range 10 to 15 feet. • Dwarf trees from 5 to 12 feet. • Home gardeners use mostly semi-dwarf/dwarf trees. • They are shorter, occupy less space, and a homeowner with limited land can grow more species & cultivars of fruit. • Picking, pruning & spraying are easier—no ladder needed. • Dwarfed trees also bear sooner.

21. DWARF FRUIT TREES • Dwarf trees are most commonly produced by grafting onto a dwarfing rootstock that preventsthe cultivar from growing to full size. • Combines dwarf characteristic of one cultivar withexceptional fruit of another. • Produces a plant with the desirable characteristics of each.

22. DWARF FRUIT TREES An interstock would be used, when the stock & scion are incompatibleand will not graft together.But each is compatible with the interstock. Figure 9-3 An interstock grafted betweenthe rootstock and scion on a fruit tree. • Sometimes three cultivarsare involved: • A rootstock. • A scion. • An interstock.

23. DWARF FRUIT TREES Many nurseries use this technique to avoid poor root systems inherent with many dwarfing rootstocks. Figure 9-3 An interstock grafted betweenthe rootstock and scion on a fruit tree. • Grafting with an interstockcan be used to combine: • Superior fruiting (in the scion). • Dwarfing (in the interstock). • A vigorous root system (in the rootstock).

24. DWARF FRUIT TREES • In genetic dwarfing, the fruiting portion of the tree remains small due to its genetic makeup rather than because of a dwarfing rootstock. • Genetically dwarf trees are also frequently grafted, particularly for vigorous or disease-resistant qualitiesthe rootstock can contribute to the tree.

25. PLANTING FRUIT AND NUT TREES • Planting fruit & nut trees is the same as plantingan ornamental tree. • Deciduous trees normally are sold leafless and bare-rooted for planting in the fall or spring. • Evergreens such as olive, citrus & avocado, sold in plastic sleeves or containers, can be planted at any time of year. • The hole should be dug large and deep enough to accommodate the root system without crowding. • After settling the plant, fill with the removed topsoil. • Organic matter such as peat moss/compost can be added. • Watering thoroughly afterward is essential.

26. PLANTING FRUIT AND NUT TREES If the scion comes in contact with soil, it will send out roots of its own, and the desirable rootstock characteristic willbe lost. Figure 9-4 The graft union of afruit tree. Photo by Rick Smith. • Placement of the graft union above ground at planting is necessary to retain the special qualities of the rootstock.

27. PLANTING FRUIT AND NUT TREES • Staking for support may be necessary for the first year or two until the root system is large enough to anchor the plant. • Many dwarf cultivars are very shallow and fibrous-rooted, so permanent staking or trellising may be advisable. • Use a short stake attached to the trunk using a wire covered by a section of rubber hose or rag pieces. • Bare wire/string may injure bark by rubbing or girdling. • If fruit & nut trees are not pruned before shipping, they will have to be pruned after planting.

28. MAINTENANCE OF TREE CROPS Watering • Watering of a fruit/nut tree varies with the species. • Most produce best only with regular rainfall/irrigation. • Some, like the olive, are drought-resistant, adapted to arid climates. • A newly planted tree should be watered deeply every 1 to 2 weeks during its first growing season. • Decrease frequency in subsequent years to about every 3 weeks, depending on soil water-holding capacity & rainfall. • Many orchards use drip irrigation systems & these systems can be recommended highly for home use. • Conserves both water and labor.

29. MAINTENANCE OF TREE CROPS Fertilization • Tree crops normally are fertilized yearly on a precautionary basis rather than because thetree has shown any distinct nutrient deficiency. • Without seasonal soil tests, it is impossible to apply the exact amount of fertilizer required. • Yearly fertilizing is used to prevent possible deficiencies. • The drill-hole method is used when the area under the tree is covered with grass or groundcover plants that would be injured by the fertilizer application.

30. MAINTENANCE OF TREE CROPS Fertilization • General recommendations specify applying granular-type fertilizers in spring before, or just as new growth starts. • 1/2 cup of nitrogen-rich fertilizer per inch of trunkdiameter will supply an adequate amount of nutrition. • A second application should be given in midsummer. • Micronutrient fertilizers frequently prevent iron & zinc deficiency on citrus & pecans in alkaline soil. • Foliar or soil applications should be made repeatedlyuntil the foliage regains its healthy green color.

31. MAINTENANCE OF TREE CROPS Pruning • Most nuts require no pruning & many are so tallit is impractical to do so after the first few years. • Most deciduous fruits should be pruned, however. • The three main pruning styles are: • Central leader, modified central leader, and vase shape. • Espalier training styles are less commonly used. • In all cases the object of the training is to producea tree with well-placed, strong branches capableof supporting a heavy fruit weight without breaking. • Style selected depends mostly on the species of tree.

32. MAINTENANCE OF TREE CROPS Pruning Pruning starts at planting, if needed, with selection of the central leader & several scaffold branches spaced widely around and down the trunk. Figure 9-5a Fruit tree pruned to central leader form. Drawing by Bethany Layport. • Central leader form is used on most nut trees, sweet cherries, occasionally for apples & pears.

33. MAINTENANCE OF TREE CROPS Pruning Pruning after the first severalyears should consist ofremoving rootstock suckerand competing branchesarising from the trunk. Figure 9-6 Pruning suckers fromthe base of a tree. Author Photo.

34. MAINTENANCE OF TREE CROPS Pruning Tree is pruned to a final form after planting by selecting the lowest, strongest branches. Common on peach, apricot, and nectarine. Figure 9-5b Fruit tree pruned to a vase form. Bethany Layport. • Vase form, or open-center form, allowstwo to five scaffold branches to growfrom a short trunk.

35. MAINTENANCE OF TREE CROPS Pruning Figure 9-5b Fruit tree pruned to a vase form. Bethany Layport. • Branches originate close together on the trunk & the central leader is removed to a side branch. Vase pruning opens the center of the tree to admit light & encourage fruiting, and keeps the bearing branches of the tree low for easy picking.

36. MAINTENANCE OF TREE CROPS Pruning Figure 9-5c Fruit tree pruned to modified central leader form. • Modified Central Leader Form  - the tree is first trained to a central leader form for 2 to 3 years. The next year the leaderis cut back to a strong sidebranch, leaving three tofive scaffold branches. With the leader gone, side branches grow stronger &longer, and height of thetree is kept in check. Suggested for apples, pears, plums & sour cherries.

37. MAINTENANCE OF TREE CROPS Pruning Figure 9-7 Sample espalier forms for fruit trees. • Espalier training starts when the tree is planted. • It consists of pruning, bending & tying branches asthey mature, to achieve a symmetrical shape. • Espaliered fruit trees do not produce as large a crop.

38. MAINTENANCE OF TREE CROPS Training • Many fruit trees branches grow upward instead of outward, with narrow branch angles called crotches. • As branches enlarge, pressure at the crotch causes weakening and a tendency to split under snow/fruit loads. • When young and flexible, a branch can be trained todevelop a wide crotch.

39. MAINTENANCE OF TREE CROPS Training The branch should be tied for one or two seasons and frequently checked to make sure it is not being injured. After the rope is removed, the branch will grow out instead of up. Figure 9-8 Tying a fruit tree branch to the ground to encourage a wide branch crotch to form. • Tying involves bending a flexible young branch down and securing it to the ground with a stake.

40. MAINTENANCE OF TREE CROPS Training Spreading uses forked or nail-tipped pieces ofwood wedged tightly between a young branch& the trunk of a tree to widen the crotch angle. • As with tying, the spreader is left in place for one or two seasons to encourage the crotch to remain open. Figure 9-9 A branch spreader inplace in a tree. Rick Smith photo.

41. MAINTENANCE OF TREE CROPS Fruit Thinning • Thinning is removal of a portion of the fruits on a tree while they are still small. • Many fruit trees produce more fruit than can fully mature. • Unthinned, fruit will be undersized & frequently poorly colored. • Excessive fruit load may weaken the tree. • Alternate-year bearing in may result, with the fruitless year devoted to regaining the vigor of the tree. • Thin fruits when 1/2” to 3/4” in diameter & after natural drop of young fruit occurs. • The number of fruits that should be left on a treedepends on the species.

42. MAINTENANCE OF TREE CROPS Fruit Thinning In practice, fruits are not spaced evenly but are closetogether on strong branches and far apart on weak ones. The largest, healthiest fruits should always be left onthe tree, regardless of their relative spacing on a branch.

43. MAINTENANCE OF TREE CROPS Fruit Thinning • If a gardener has a large orchard, hand thinningmay be impractical. • In that case, the trees may be thinned chemicallywith a hormone application shortly after bloom.

44. RENOVATING NEGLECTED FRUIT TREES • When buying an older home, it is common to inherit at the same time at least one neglected fruit tree. • The tree may have dead limbs or be diseased, maybe bearing sparsely, with small fruit of poor quality. • Fruit quality can be improved to an acceptablegrade and the tree may be valuable for shadeand flowers. • If the tree is given some attention.

45. RENOVATING NEGLECTED FRUIT TREES • Renovation pruning should be spaced over 3 years to avoid stimulating excess sucker growth. • The first pruning should remove dead wood, suckers,and some of the crossing branches. • Leaves & fruit that drop in fall serve as a sourceof disease reinfection, and should be removed. • A disease- and pest-control program should be started. • During the next two seasons, excess branches can be removed to admit light & improve fruit production. • Fertilizer can be withheld until after pruning is complete but should be applied if deficiency symptoms are present.

46. FAILURE TO BEAR Age • The age at which a tree can be expected toproduce its first crop varies with the species. • Most dwarf and semi-dwarf types bear by the thirdor fourth year after planting.

47. FAILURE TO BEAR Pollination Problems In most fruit & all nut trees, there must be pollination and fertilization to set a crop. • Exceptions are rare but include fruits such as navel oranges, persimmons, and some figs and pears. • These fruits set parthenocarpically, without fertilization. More often fruit trees are incapable of pollinating themselves and are called self-sterile. • Cross pollination with another compatible cultivar is necessary to produce a crop. • Self-pollination is the rule on most nut trees, and a few fruit trees, most of which bear separate male & female flowers, pollinated by wind.

48. FAILURE TO BEAR Self-Sterility Causes • Incompatibility of pollen with female flower parts. • Pollen grains do not function correctly when in contactwith the female flower parts of the same plant. • Pollen may fail to germinate or grow too slowly to the egg. • Nonviable pollen. • The pollen does not germinate. • Failure of the pollen and female flower parts to attain maturity at the same time. • Pollen is shed after the female flower parts have passed their receptive stage or before they have attained it.

49. FAILURE TO BEAR Self-Sterility Causes • Dioecious plants. • In the case of tree crops such as the date, male andfemale flowers are produced on separate plants. • No pollen is produced with which the tree can self-pollinate.

50. FAILURE TO BEAR Other Causes of Failure • In mild climates, winter temperatures may not be sufficiently low to provide the necessary chilling period to produce the normal amount of flowers. • The flowers may be reduced in number and sporadic. • Deciduous fruit and nut trees are most susceptible. • A tree receiving insufficient sunlight will produce lush vegetative growth but few flowers and fruits. • Frost or rain during the pollination period can damage flowers or restrict bee activity & no cropwill set.