Points to bear in mind during orchard selection include the cultivar and rootstock recommendations for the relevant area; the suitability and preparation of the soil; the availability of certified nursery trees; and, when replant soils are to be used, a report on the pathogen status of the soil. Once a decision has been made on the cultivar and rootstocks to be planted growers should order certified disease and insect free trees from a reputable nursery.
Before planting the following adjustments should have been completed: pH adjustment of the soil; pre-plant fertilization (the amount of phosphate and potash applied pre-planting is determined by the results of the soil analysis. Your consultant or horticulturist should advise on this matter.); subsurface drainage/ridging (if necessary) and soil preparation including deep cultivation; establishment of windbreaks and installation of underground components of irrigation systems.
When choosing land for an orchard, the ideal site is on elevated land: This allows cold air to travel to low spots during the cool season. Cold air is heavier than warm air and will travel down to lower elevations. Dense woods or high hills and mountains will block cold air as well and also sites directly on top of hills or ridges may be too windy or cold during winter.
Slope and the direction of the slope are also important when evaluating an orchard site: A south-facing slope warms up faster in spring, the opposite is true for a north slope. The degree of the slope can affect an orchard site, an ideal slope is 4 to 8%. The slope is calculated by taking the height of rising in the land over the distance it rises. A steep slope makes harvest difficult. The bottoms of steep slopes are sometimes too fertile. Overly fertile soils can lead to excessive tree growth at the expense of fruit production.
As mentioned earlier, soil type and drainage are important to consider: Most fruit and nut trees require well-drained loam that is a minimum of 3-4 feet deep. Good drainage should take preference over soil depth. The tops of ridges and hills will have shallow soil due to erosion. Fruit trees grow well in soil with a pH of 6.0 to 6.5. Higher or lower levels of pH can cause nutrient deficiency.
Once a suitable site has been chosen for an orchard it is necessary to prepare the land. A soil test should be taken to determine the fertility of the soil. Local soil testing laboratories have the resources to conduct a soil test, or, a soil test kit can be purchased and done by the grower. If replacing an old orchard or starting a new one, take the soil sample after removing as many of the roots as possible. If the land being prepared for orchard was previously pasture, a nematode test should be conducted.
When choosing a fruit or nut tree there are factors to consider.
Size: Fruit and nut trees can grow to be very large and take up a lot of space. Some fruit trees require two different cultivars to pollinate and produce fruit. Larger trees will produce more fruit but will also be more difficult to prune and harvest.
Rootstock: Improved fruit trees like dwarf varieties are produced by grafting. A rootstock, a healthy plant used for the base of grafting a scion, from one cultivar is grafted to the scion of another cultivar giving improved qualities. Grafting can improve the size, disease resistance and in some fruit species, multiple fruit varieties can be produced on one tree. The rootstock determines the size of the tree. If a rootstock of a dwarf variety is grafted to a standard scion, the tree will be a dwarf.
In commercial orchard operations, a common arrangement is one row of pollinizer trees (the tree producing the pollen) between four rows of the main variety. Sizes of trees impact spacing and arrangement as well. Semi-dwarf and dwarf pollinizers are placed every fifth tree in a row and staggered from row to row. The maximum distance between pollinizers and the main variety of trees is 15 meters.
Space between trees should be determined by the mature size of the tree. To determine the mature size, ask the grower from which you obtained the trees. A plan should always be made ahead of time to determine the distances between trees. Drawing a plan on paper will allow for faster and more efficient planting. Planning ahead of time will give you the ability to dig the holes right away and be ready to plant the trees as soon as they are available. Once a plan is made and the trees are available they need to be planted immediately.
Fruit trees may be planted in early spring as soon as the ground temperature is warm enough. Dig a hole wide and deep enough for the roots to lay comfortably in the hole without the roots wrapping around themselves. When the roots wrap around themselves and begin growing they will eventually “choke” the tree and cause poor yield or death. Trim off any broken roots. If the tree is grafted the graft union should be at least five centimetres above the ground. If the tree is planted too deep and the graft union is below the soil line, the scion variety will form roots and the tree will become a standard-sized tree.
Once the hole is dug and the tree placed in, only clean soil and water should be placed back in the hole. If the soil needs amending, place some peat moss into the hole, but no fertilizer. Too much fertilizer on the small tree can burn the roots or cause excess foliage production. Before filling the hole, be sure the tree is straight. After the tree is planted, gently tamp the soil with your feet and water with 7.5 to 20 litres of water. Once the trees have been planted, they need routine care.