For San Luis Obispo and Santa Barbara Counties’ Backyard Orchardists
Prepared By: John H. Foott, Farm Advisor San Luis Obispo/Santa Barbara Counties, 1991 | Revised: Frank Laemmlen, Farm Advisor Santa Barbara/San Luis Obispo Counties, 1993 | Mary Bianchi, Farm Advisor San Luis Obispo/Santa Barbara Counties, 2002
The attached list of fruit and nut varieties is for the coastal and inland areas of San Luis Obispo and Santa Barbara Counties. Due to the many micro-climates in the coastal counties, it is difficult to advise the backyard orchardist on varieties suited to every situation. The following list of varieties is not complete. It will, however, assist you in choosing varieties that may be suited for your particular location.
Temperatures during the winter and spring are the key element in choosing fruits and nuts for coastal and inland areas. Spring frost is the main hazard for early fruit and nut varieties in the inland areas, killing both new leaves and flowers. Conversely, too few hours of cold temperatures, or chilling, causes problems with fruit production along the coast. Insufficient chilling is probably the most limiting climatic factor for apple, apricot, nectarine, peach and sweet cherry.
Deciduous fruit and nut trees enter a dormant, or “rest” period after leaf fall. Trees are kept in dormancy due to natural growth inhibitors. These natural inhibitors prevent growth from beginning during atypical periods of warm winter weather. Dormancy is broken in the spring when sufficient cold temperature breaks down these natural growth inhibitors within the tree. A specific number of total hours of chilling (temperatures between 32oF and 45oF) are required to break dormancy. The total number of hours varies with variety, even within species. Plants that do not get adequate chilling leaf out later in the season (delayed foliation), have a prolonged blossoming period, buds may deteriorate and drop, and few, if any, flowers are produced. Without flowers, there is no fruit.
The number of hours below 45°F is a fair index of the adequacy of winter chilling. Both the absolute number and distribution of the hours below 45°F need to be considered. December and January are usually the most critical months. If each of these two months has approximately 400 hr of fairly evenly distributed temperatures below 45°F, then troubles related to mild winters are less likely. Periods of a few days to a week or more of mild weather may offset or reduce the effectiveness of accompanying periods of good chilling weather. More chilling hours are usually necessary in those years or districts with interrupted periods of adequate low temperatures and warm sunny days.
When purchasing fruit and nut trees for coastal areas, the home orchardist should ask how many hours of chilling the variety needs, and select varieties having chilling requirements below 300 hours.
Most fruit and nut tress grow best in areas sheltered from the wind and in well-drained soils. After planting, most fruit and nut trees benefit from a whitewash treatment to the trunk to protect against sunburn and insect damage. Follow good cultural practices such as regular watering, fertilizing when necessary, and insect and disease control. Prune deciduous trees annually, thin the fruit, pick at proper maturity and your trees should produce good quality fruits and nuts for many years.
Additional Resources
California Backyard Orchard A University of California Resource for Fruit and Nut Crops. 2002 http://homeorchard.ucdavis.edu/
California Master Gardener Handbook. Dennis Pittenger, editor. 2002. University of California Agriculture and Natural Resources Publication 3382.