Concerning tropical fruit trees in Riverside, California: I've lived in Riverside for the past 50 years and have learned that there are many distinct microclimates even on one property of only 3/4 acre. Many tropical species are under constant winter stress from occasional low winter temperatures that for some species stimulates fruit production, while for others restricts their ability to produce fruit. Also, the typical cool period in springtime can cause decline of tropical species: dwarf bananas especially. Trial and error plantings in one's backyard eventually locates suitable areas for different species. Leichy requires afternoon shade, Cherimoya requires overnight wetness (or fogging) to set fruit as pollen is formed in the evening while pollination is only possible the following morning. The Philippine species of mango do very well even thru' cold winters but fruit will not set well during wet springs. Several species of Sapote are well adapted after they are over five years old. Colonel Beaumont variety of macadamia is the most prolific bearer in Riverside, but they are rarely available anymore. Coconut will not survive prolonged cool springs, but pineapple plants will survive the required 1.5 years to fruit if kept moist. The quality of yard-grown pineapple is especially good. Most available mandarins, oranges and grapefruits typically give excellent yields, altho' all citrus is now under threat of eradication due to the invasion of the Asian citrus psyllid. The scientific community that used to be on top of such invasions is vastly understaffed due to cutbacks in support from government and growers as well as the elimination of strategic laboratories that were located in foreign areas. Over the past 20 years funding has rather been diverted to genetic engineering.
The above examples are just a few of the many tropical and subtropical species I am familiar with for Riverside, and I will be happy to discuss others as well at
discoverfl@live.com.
Dr. E. F. Legner, Professor Emeritus, University of California