news from up the creek
TRIAL BY FIRE
Author experiences a fresh start in the olive grove.
WRITTEN BY MIKE MADISON
ILLUSTRATION BY JOSH DIAZ
On a summer day in 2013, a downed power line sparked a fire in our olive grove. The fire burned along slowly in the dry grasses on the orchard floor, and where it encountered an olive tree, the tree burned as well. Olive oil is not just in the fruits; it’s also in the leaves and the wood and the bark, so olive trees are surprisingly flammable. By the time the fire department had extinguished the blaze, 263 trees had burned. Some were burned just on one side and would recover, but others had been girdled by fire and would die.
It is a virtue of olive trees that they will regenerate from the stump. I sawed off the badly burned trees flush with the ground, and by the next winter a thicket of shoots was growing up from the stump. I would choose a vigorous shoot to become the trunk of the new tree and cut away the other shoots. Now, three and a half years after the fire, the regenerating trees are bearing a light crop of olives.
For California orchards, this ability to regenerate from the stump is limited to olives, figs, and dates. All the other orchard trees are grafted, so that the roots are a different variety, or even a different species, from the tops. We find pears on quince roots, apricots on wild plum roots, and almonds on peach roots. There are advantages to grafting: It speeds production in the nursery, confers disease resistance and cold hardiness, and it may increase vigor of the trees, or, paradoxically, decrease vigor, leading to a dwarf tree (apples, citrus), useful in a crowded, suburban setting. If you cut a grafted tree off at the ground, what grows back is the rootstock, not the desired tree. Olives and figs are propagated by cuttings rather than grafting, and so they are on their own roots and can regenerate.
In addition to their ability to restart from their roots, olive trees have other advantages as a crop. They are tolerant of drought and cold; they are relatively free of pests and diseases; they will grow well on rocky, infertile soils; they do not require bees for pollination; the harvest is stretched out over a long period (October to February); and the trees will endure for centuries. What’s not to like? Well, there’s one thing: If you were expecting to earn a good income from your orchard, then any tree crop other than olives would be a better choice.
Mike Madison operates a family farm near Winters, Calif., producing olives (Yolo Press Olive Oil), figs, apricots, melons, and cut flowers. His books about Sacramento Valley agriculture include Walking the Flatlands and Blithe Tomato.