I would guess salt burn. How deep and how frequently do you water them? In addition to the comment of not bearing true from seed, be aware that a seedling takes 10-15 years to fruit, and while avocados may be self fertile a compatible cross pollinator (they have a designated A and B grouping with cross pollinators being from the other group) makes a huge difference in yield. On the other hand the advantage of a seedling is full size and it is a proven winner in your soil and environment by thriving. And that one in the photo looks very nice indeed. I would also get that trunk painted white. This post was edited by Fascist_Nation on Wed, Jan 8, 14 at 14:32

Simon, thanx for that helpful post. Full sun. Couldn't get better exposure. Since planting 2.5 years ago, haven't fed ava except with humus and mulch. Leaves are rich dark green. No chlorosis at all. But, it's probably time to apply a small amount. This is my first avocado, and I have no complaints. Only a little troubled that the trunk and branches are SO flexible. And, forget about it if Ava fruits this year. No way could the branches support heavy fruiting. I would have to stake. In the meantime, I feel like I'm taking a very slight chance on breakage (the branches are heavy with foliage), but I'm betting, as you pointed out, that I'm helping it become a stronger plant, physically. We get hurricanes here and I KNOW I'll have to protect her then with some significant staking, at least for the next couple of years. I've posted a picture which is not the best, but shows how it leans over and from a short distance resembles a bush, but is really just a single trunk that does not stand up. Thanks again.

All I can tell you banana fan is that my two avocado trees grew fairly slowly the first couple of years, then took off. I think they like to establish a strong root system first before shooting up. My trees are both Mexican varieties.

Nancy: As much as I hate to prune my trees back......I hate losing all that growth....I can't do anything but admire how nice your trees look. When I get the time...in my retirement years (if they ever get here), I may have to become a more avid pruner. Not promising anything. I do wonder how heavy fruit set affects these trees that are so vertically challenged. I have had a Bombay mango totally break down with a heavy crop as it had grown much more laterally than upwards. I'll be watching as you encounter this heavy fruiting phenomenon on your trees. Keep up the good work. Harry