Avocado tree leaves turning brown

Question

I have a grafted has avocado tree that I kept inside for most of last winter (South Africa). It has been outside since November last year and seems to be stalling from the initial good growth when it was inside and also when it first moved outside in summer (November to February).

I have been giving it water twice a week, ensuring it is wet throughout the soil. The soil has got good drainage and the pot has been filled with drainage stones in the bottom, in addition to the holes.

The leaves have started showing brown marks in the middle (not the tips) and some of the top stems also start to look brown. What could this be?

1. Could it be getting too much sun?
2. Since it was growing well, I don't believe it could be root bound in the 110L pot?
3. I added fertiliser during the last week to see if this would help? I guess this will only show in a week or two if the soil was lacking nutrients.
4. Could it be that it is too close to the outside LED light that is on during the night?

Answer 1

In my experience avocados tend to grow in spurts; they have rest or quiet periods and then suddenly decide to make a rush for growth, sending up little new leaves at the growing point which suddenly overnight it seems expand into big leaves and then just sit there for a while before making a repeat performance.

Avocados grow all over the Caribbean in full bright sun; they are native to central Mexico so too much sun is almost never a problem, provided they have enough water, drainage and a small amount of fertilizer.

Looking at your tree carefully it seems to have a lot of top growth on a fairly spindly stalk. When the growth spurt starts it will need to access a lot of moisture from the stem and this may explain the brown patches. The growing tip looks like it is in a low part of the growth cycle right now - you can't hurry it, it will suddenly wake up and grow vigorously. If the stem does not thicken up willingly you may have to prune it back fairly hard to force the stem to expand.