A recent post by Soil Matters, Get the Scoop brought home recent frustrations and conversation with my Dad. My fruit and nut trees have been burning and dying from desiccation in some areas of my yard. My Dad tried to explain to me that I was “missing some concepts” regarding transpiration and soil salinity. Did he forget that I used to teach about transpiration and osmosis to middle school, high school and community college students? I tried to explain to him that water is very expensive in the Town of Apple Valley. Even with frugal irrigation practices, my water bill can be $300 a month in the summer. My neighbor with a lush garden told me that he spends $800 a month on water. I need a more cost effective solution. Eventually I directed the conversation to how to live with the salinity without running up the water bill. He recommended olives and pomegranates in my “burn zone” because they are more tolerant of soil salinity. Funny, the only surviving trees in my more exposed area of the yard happen to be olive trees, a dwarf pomegranate and a persimmon. So far only the mission olive still produces fruit. Typically the ravens get to it before I do. The pomegranate and persimmon never did produce. I do keep them pruned down to a height that is lower than the fence up wind of them and apply a lot of mulch. Perhaps the addition of gypsum and more rock mulch would help.
My apricot, plum, nectarine, walnut, and quince all grow where they get flooded with stormwater runoff that collects from a four block area at my corner. I diverted the standing flood water with swales to my fruit trees to get some free irrigation water.
Evidently that is enough to provide an annual leaching of salt from the root zones. Still I can tell which branches get more exposure to high winds in 100+ ° Fahrenheit weather. They get crispy. Leaves and walnuts burn on the upwind side of the trees. And yes, I will be sending out some soil samples this summer, adding gypsum to the soil around my trees and adding rock mulch to slow evaporation from the soil. I also see adding a few well placed olives to serve as a wind break. If any of you know of additional home orchard trees that tolerate drought and salty soil, please let me know. I have some very expensive “vertical mulch” to replace.