The olive tree's unusual climate requirements require special attention to the tree during winter.
The olive tree has narrow and challenging requirements in terms of the climate and temperature it needs in order to produce fruit. Olive trees can sustain damage or die during freezes; but they also require vernalization -- exposure to cold night temperatures -- in order to set fruiting buds over the winter. This makes the tree nonproductive in mild climates. Successfully growing olive trees requires protecting trees from winter freezes. Does this Spark an idea?
Cold Protection
Olive trees begin to sustain damage to their stems and foliage when temperatures drop below 17 degrees F; they can die back to the ground if temperatures drop below 10 degrees F. Because olive trees require cool winter nights in order to set fruit, regions suitable for growing olives often experience potentially damaging freezes, you'll need to consider winter protection. Studies conducted by Jim Denny of the Texas A&M University Extension Service found that even in the relatively mild USDA plant hardiness zones 8 and 9, trees still experienced killing frosts three winters out of 10. To protect young trees, build a mound of soil 1½ feet tall around the trunk in late autumn and remove it in early spring. Keep an eye on the weather reports; when temperatures below 17 degrees F are predicted, cover your tree's foliage with blankets or burlap.
Water
Olive trees can withstand dry spells but benefit from at least one good soaking each month. If winter months bring dry weather, provide a deep watering once a month. When watering, don't just soak the area around the trunk but cover the entire root zone, which can extend one and a half times the diameter of the tree's canopy.
Fertilizer
Olive trees generally require very little special fertilization, but trees do tend to benefit from nitrogen fertilizer. The Texas A&M University Extension recommends applying ½ lb. to 2 lbs. of nitrogen fertilizer in December. This early winter application ensures the tree has plenty of time to build up adequate nutrients in time for spring flowering and fruit set.
Repairing Cold Damage
As Denny's studies indicate, if you live in a region suitable for setting fruit on your olive trees, you should expect the tree to sustain occasional damage from the cold. Wait until spring and the beginning of new growth to trim away any dead or damaged branches and foliage. Even if your tree sustains extensive damage, do not give up on the tree. Olive trees remain remarkably resilient, and even trees killed to the ground can rejuvenate from surviving tissue in their root systems.
Tags: below degrees, Olive trees, around trunk, benefit from, drop below