Marin IJ Articles
October 30, 2010
How wonderful it is to enjoy tree-ripened fruit from your orchard. Ripe peaches from the grocery store don't compare with the lushness of a freshly picked peach from your own orchard.
With a little sleuthing, you can grow the tastiest varieties, many of which are not available in local supermarkets. Take time to do some research before you purchase trees for your orchard; microclimates differ with elevation, marine or fog influence, wind and frost patterns, rainfall, slope, average temperatures, and temperature extremes. Learn the basic care of each fruit tree you choose to plant. Some helpful resources include: "The Home Orchard," written and published by the University of California; "Golden Gate Gardening" by Pam Peirce; Sunset's "Western Garden Book" or its "Western Garden Book of Edibles."
Our relatively mild winters and long growing season allow us to grow many species of apples, pears, plums, cherries, grapes and blueberries. Our small orchard in Inverness boasts several varieties of pears, apples and plums.
Bare-root trees establish themselves better than container plants. Buy bare-root fruit trees during the winter and early spring. If you buy a tree or shrub in a container, reject plants with visibly circling roots. Consider choosing dwarf or semi-dwarf varieties, if you don't want to be climbing ladders to harvest fruit. To save yourself a lot of hassle, select trees that are disease resistant. The plant label is a valuable source of information for growing success.
Follow these simple rules for getting your orchard off to a successful beginning:
O Site selection: The best preventative medicine for growing a fruit tree is to plant it in a spot that provides it with deep, organically rich soil, good drainage and full sun. Amend compacted, clay or sandy soil by adding peat moss and compost to the planting hole. Sunlight is a wonderful fungicide. Although wind dries off the moisture that fungi need to thrive, avoid a spot in which a tree is buffeted by cold spring winds. Follow spacing guidelines--good air circulation around trees can help prevent disease.
O Diversity: A diversified home orchard will be better able to ward off pests than a monoculture. Usually, one tree of each kind is enough for the average family.
O Mowing and mulching. Keep your orchard mowed. Undesirable pests hide in tall weeds. A 4- to 6-inch layer of mulch such as chopped leaves, clippings, chips and other organic waste, can improve soil fertility, help control weeds and conserve moisture. Keep mulch several inches away from the trunks of trees, as mulch can trap moisture in the root crown area, encouraging root rot.
O Pruning: Most temperate fruit trees should be pruned during the dormant season when the leaves are off the tree. Summer pruning is used to manage overly vigorous trees that are too large. Prune a mature tree to keep it healthy, to keep it within its allotted space, and to keep it bearing regular crops of the best fruit possible. Cut back diseased/dead wood to healthy, light-colored wood. Species that bear fruit primarily on long-lived spurs that continue to bear fruit regardless of new shoot growth (such as apples, pears and cherry) need to be topped back after five to 10 years. Species that bear laterally on 1-year-old growth (peaches, nectarine, fig, persimmon, kiwi, walnut, olive) are pruned more heavily in winter to ensure adequate shoot growth and fruit production. To avoid spreading disease with your pruning shears, sterilize the shears between cuts with a dip or wipe it with alcohol.
O Irrigation: Most fruits require regular water during fruit development. Avoid letting the soil around newly planted trees or shallow-rooted dwarf varieties dry out. An inexpensive soaker hose works well as it sends water to the roots where it is needed and concomitantly prevents water from getting on the leaves or fruit where it can promote the growth of fungi. Purchase a moisture meter to check on the moisture level of the soil.
O Managing pests: Cultural practices, physical barriers and devices, biological control agents and low-environmental impact pesticides are all tools commonly used in integrated pest management (IPM). Choosing the right tool and applying it properly and at the right time are the keys to success. For comprehensive information on pests/disease in plants, go to the University of California's statewide IPM website at www.ipm.ucdavis.edu.
O Other considerations: Fruit trees must be exposed to a set number of hours at temperatures below 45 degrees in winter if they are to bloom normally and grow well in the spring. For example, apple trees must receive approximately 500 to 1000 hours of winter chill, depending on the variety, to produce desirable fruit. If a fruit or nut tree does not receive enough chilling hours during winter, flower buds may fail to develop, leaves may appear later than usual and the bloom period may be extended. The tree may produce little or no fruit that year, and any fruit that does appear may be deformed or smaller than normal. For those who live near Black Point and Point San Pedro or comparable locations, comprehensive data on chilling hours for the current year can be found at the University of California at Davis's website http://fruitsandnuts.ucdavis.edu/weather.
As with chilling hours, each species and variety has its own requirements for hours of heat exposure. This means that fruits such as peaches, which have a prolonged ripening period, may not ripen properly in cooler coastal areas. Thus, it is critical when selecting fruit or nut trees for your home garden to choose species and varieties that are compatible with the average number of chilling and heat hours in your area.
The University of California Marin Master Gardeners are sponsored by UC Cooperative Extension. For questions about gardening, plant pests or diseases, call 499-4204 from 9 a.m. to noon, and 1 to 4 p.m. weekdays, or bring in samples or pictures to 1682 Novato Blvd., Suite 150B, Novato.
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