Thanks for the question.
There are a couple of possible causes for the leaves turning inwards
on your tree. This can be caused by disease. Olive trees can be
attacked by a number of different diseases, depending on the region
you are living in.
Verticillium wilt is a fungal disease that enters the plant through
its roots. It is not limited to olive trees and can attack a number of
different plants and trees.
Treesforyou.org has this information on the disease:
?Verticillium wilt fungus is a sneaky disease, entering a plant
through the roots in the soil. Infections are not obvious like some
other diseases, such as powdery mildew or sycamore blight. Symptoms
can be acute... with leaf curling and drying, abnormal red and yellow
coloring of the leaves, partial defoliation, wilting and dieback of
branches. This wilting and dieback will typically develop on one main
branch, a sector of the crown, or an entire side of the tree. Chronic
symptoms are stunted growth, yellowish leaves, crispy brown edges on
the leaves, slow and stunted growth, heavy seed crops, and branch
According to GardenSouthwest.com:
?Signs of verticillium wilt include new leaves rolling inwards and
losing their deep-green, waxy luster and becoming dull gray and brown.
Leaf-drop and twig die-back may follow, depending on the severity of
the infection. Tree death rarely occurs, rather portions of the tree
will die and then new growth may develop from dead areas. The only way
to control this disease it to plant resistant varieties of olive such
If you suspect that your olive tree may be suffering from this
disease,the best thing is to get a professional to take a look at it.
I realise that your olive tree is in a pot, but this fungus can
survive in soil for 14 years (at least), so it may be worth checking
This article from the South Australian Research and Development
Institute discusses the disease:
?Symptoms described are collapse and death of one or more branches in
the first hot weather of the season, with dead leaves and bloom
remaining attached to branches, but without the vascular
discolouration inside branches characteristic of the disease in many
other crops (Teviotdale, 1994). The fungus can survive in soil for at
least 14 years, and infection is favoured by cool, moist conditions.?
The California Rare Fruit Growers:
?In California, verticillium wilt is a serious fungal disease. There
is no effective treatment other than avoiding planting on infested
soils and removing damaged trees and branches. A bacterial disease
known as olive knot is spread by pruning with infected tools during
Root rot is another common disease affecting olive trees.
??infected plants will suddenly wilt during the summer when
temperatures are high. Dead or dying foliage will remain attached to
the plant and the roots of the plant become rotted and brown in
However, this disease is usually found in mature olive trees, and as
already mentioned, during seasons of high temperature. Once again, if
you suspect this disease may be the cause of your plant?s problems,
please consult a professional.
More examples of the pests and diseases that can affect olive trees
can be found at OliveBusiness.com:
There is the possibility that the problem could also be caused by poor
drainage. You mentioned in your question that drainage hasn?t been
great; olive trees don?t need much water. In fact, they are equipped
to deal with Mediterranean climates.
The University of Nevada, Las Vegas, has this information:
?As the olive is a Mediterranean native, watering should mirror those
climatic conditions. Summer irrigation should be deep and infrequent,
becoming more substantial during the winter months.?
The recipe Goldmine?s Gardening with Gary section has this advice:
?Give it very good light, warmth in the room, away from cold drafts
and heating vents, and water only when the top soil is dry 1" down.
You should pot the tree up into a size larger pot with new fresh soil,
to give those roots room to branch out.?
From Oakwood Aboricutural Consultancy?s website:
?Allow free drainage and get used to watering the tree on a regular
A discussion on care of olive trees can be found on the 50 Connect
Other sites that may be of help:
White Flower Farm Olive Tree Cultural Instructions (pdf format)
I hope this is of some help to you. If any of this answer is unclear,
please request clarification before rating or closing the question.
Best of luck with the olive tree!