How To Plant An Olive Tree
There are, of course, many ways to plant an olive tree and not all the experts completely agree on which method is best. What we recommend below is mainly based on the recommendations from the leading expert in California, Paul Vossen.
- Dig the planting hole about the same size as the container.
- Remove the tree from its container and examine the roots. Untwist or cut any circling roots, but otherwise disturb the root ball as little as possible.
- Before planting, the tree should be well watered.
- Place the tree in the hole slightly higher than ground level and place about one inch of soil from the surrounding area on top of the root ball while building up the grade slightly with the original soil from the hole and some surrounding soil.
- Most experts recommend not adding large quantities of organic matter or soil mix, compost, or fertilizer to the planting hole, because it can create an artificially good growing medium. The tree has to grow out into the native soil; adding a nice soil mix to a large hole, even when mixed with native soil, may create a potted effect (the roots will continue to grow in a circle) and limit root growth out into the native soil.
- Do not add gravel or place perforated tubing under the planting hole. This actually reduces drainage and can make a poor drainage problem worse.
- Weed control is extremely important to newly planted young trees for the first few years. There should never be any competition within 3 feet of young olive trees. Use fabric mulch, organic mulch, coarse straw, frequent mechanical cultivation, hand hoeing, herbicides, flaming, or whatever is needed to eliminate weeds within this radius.
- Place drip irrigation emitters right next to the tree trunk if planting in the late spring when weather can get hot. The newly planted trees should be irrigated daily right next to the root ball, throughout the summer. The following year, the emitter should be moved away from the trunk at least 24 inches. A second emitter should be added to each tree, no closer than 24 inches as well. With fall planted trees, the emitters can be placed 24 inches from the tree in the spring.
- Mini sprinklers should ideally be placed to wet the area between the trees without wetting the tree trunks. They should be run long enough to wet down about 2 feet (usually applying about 4 inches of water). Place some empty cans under the mini sprinklers to determine their application rate. Most mini sprinklers apply about 0.10 to 0.20 inches of water per hour, so they would have to run approximately 20 to 40 hours to apply 4 inches of water.
- Begin irrigating the trees as soon as the soil becomes slightly dry. Drip-irrigated trees should be watered every day for about an hour during the summer months. Mini sprinkler- irrigated trees should be watered about twice a week. Once the trees become more established, the irrigation frequency and duration can be modified (see Water Usage and Irrigation).
- Fertilize newly planted trees only after good growth begins in the spring. Place the nutrients directly below or through the irrigation system. The trees mainly need some nitrogen. Use compost, conventional fertilizers, or concentrated organic fertilizers.
- Mulching helps to conserve water, cool the soil, and reduce weed growth. The best mulches to use are those that contain plenty of nitrogen and other nutrients to feed the tree. These include lucerne, soya bean and pea hay. Keep the mulch 4″-6″ away from the base of the trunk to allow the tree to breathe. As the mulch decomposes over a period of time, the nutrients are transferred into the soil by earthworms, rain and microorganisms.
- Train the trees as little as possible the first four years, only the minimum to achieve tree form. Most trees in the open center form should only have their trunk cleared of side branches below 3 feet and suckers removed. In the fourth to sixth year, the trees are shaped in their ultimate form. Removing too much growth through excessive pruning on young trees can significantly stunt the tree’s growth and delay production.