Avocado Tree Won't Grow Leaves
I got a small avocado tree a couple years ago. It did great the first year, and the first winter in the greenhouse developed a bunch of blossoms. But it immediately started losing all its leaves. I thought the blossoms were likely stressing it out, so I cut them off. The tree survived, but developed very few new leaves and didn't grow at all through the summer. I've fertilized it a couple times but nothing seems to help. What can I do to give it a boost?
Avocado trees in containers should be outside in the summer and moved into the greenhouse for winter protection. It's interesting your tree produced flowers since avocado trees usually start flowering at 5 or 6 years old. In the picture you provided your tree doesn't look that old. If it is old enough to flower your tree is very stunted and stressed. I would suggest you transplant the tree into a larger pot and watch the moisture level. Let the soil dry slightly before watering again. If the soil stays too wet it will cause the roots to rot. Don't fertilize again until the plant starts to put on significant growth. Fertilizer can cause problems when a plant is stressed. Move the plant to an area of high light intensity in your greenhouse away from other plants that may be competing for light. Be sure and put your tree out for the summer so it can put on good growth.