Dear Amanda, I would like some advice on saving some olive trees recently blown over a strong wind. The trees are mature i.e. ranging from 10-15 years and approx 5 to 7 meters tall. They were very shallow rooted in the rocky ground with porous gravely topsoil of approx 200mm above the clay layer, however, were quite healthy. The ground is such as to make deep root penetration difficult. The fall of the hill and the makeup of the subsoil allows for continuous seepage for several weeks after say 50mm of rain. During dryer periods they have been flooded watered weekly to the extent of the drip line with a 1m damming mound around the trunk to minimise runoff due to the slope. The Trunk diameter from 150mm to 250mm. Some of the root system is still underground as the trees were simply blown over.
Can you advise if there is any way they can be recovered?
I would appreciate any advice you may be able to offer and look forward to your response. (from NSW)
The roots have condensed in balls with a combination of a top heavy canopy. Drip irrigation has also added to the concentrated water pockets in the root zone thereby possibly causing some of the root balls. Water cannot penetrate the soil deep enough for proper root development.
What can be done under the circumstances?
These steps need to be followed:
- Cut the trees back really hard. Where you are cutting off all the foliage (or where the canopy starts from). No leaves should be present.
- Stand tree back up
- Prepare the soil and add gypsum if the clay layer is not breaking (rip where the canopy zone would be located which is usually 5m diameter).
- Add organic matter & humus to help retain moisture.
- Plant tree and stake appropriately so the tree is well supported.
- Followup water less frequently i.e.only every fortnight or even 3 weeks apart (rather than small amounts more often). Drench rather than giving a light watering which encourages deeper root development.
- As the roots settle back into the soil the foliage should follow.
Another note: Consider replacing the drip irrigation with micro sprinklers