I have an Olive Tree about 6 years old, which I put out in the Summer and bring into the conservatory in the cold months. This year it has lost lots of leaves over the past few weeks. I keep it in a pot about 18ins . Can anyone help me. Thanks
If it's been in the same pot the whole time the medium may have broken down and become airless. Or severely nutrient deficient.
Note that leaf drop can either be under or overwatering. But the leaves turn yellow first and then drop. Leaf drop due to overwatering in winter is apparently common, although I have noticed the problem a LOT more when my olive tree has been in a cold greenhouse than when it is just left outdoors. Please note that an 18" pot can handle quite a bit of frosty weather. Mine has stayed outdoors all winter so far in Vancouver BC. It has been down to -9C here, but only one or two nights. Leaf yellowing and drop is also an indicator of low nitrogen levels for olive trees (see Ron B's note above). This problem is more pronounced in winter because nitrogen uptake is less efficient in colder weather, but I would hold off fertilizing for a couple more weeks to see if you can get the watering sorted out. In Oregon, where they can grow olives commercially, they use pelletized nitrogen applied in early March. HTH, keke
It remains to be seen how long recent PNW and SW BC olive tree plantings last - we have not had a 30 year winter since 1990. Regarding evaluation of specimens left unprotected during winter in pots the top is the last part of a container tree or shrub to die from cold - most of the roots can be dead and the top may still look normal, with the root damage not manifesting until the following growing season. If the only apparent effect in a given instance is that top growth is less than it would have been otherwise it may not be noticed that there was a problem at all.
