Please Help Me Save My Dying Avocado Tree!
This is my first post on the forums, so thanks in advance for any help you might have. So here's the story:
I purchased a young grafted avocado tree from a nursery about 6 months ago. It was completely healthy at the time and I've followed proper avocado watering/lighting/soil conditions to a T ever since. I don't think I've been so adamant about taking care of a tree before in my life, yet I've been having problems with it ever since I've got it. Here are some stats and pics...
1. Lighting: The tree is in full sunlight from about 10am to sunset.
2. Location: I live in coastal Los Angeles (dry but not as hot as inland). I don't have a garden but have it in a sufficiently deep and wide pot for its age. The pot sits on blacktop, which I assume gets fairly warm during the day.
3. Soil: It is in fresh potting soil up to just above where the bulb used to be. Because that soil compacted a bit through watering, I have added about 2-3 inches of organic soil loosely on top. Before transfering the tree into this pot, I put about 6 inches-deep worth of thumb-sized rocks in the bottom of the pot (which has three 1" diamter holes along the base perimeter) to ensure proper drainage.
4. Watering: During the winter, I watered it with about a half gallon of water in the morning twice a week. When things started to warm up here in April, I upped the watering to a half gallon of water three times a week. I can see the water draining out of the holes in the bottom of the pot every time I water.
Here's the problem: after it lost its leaves around february, the plant immediately budded new leaves all over the tree in March. Things looked good for about 2 weeks. Then all of the new leaves started turning brown at the edges as if they were burnt. By mid-May, nearly all of the leaves and lower branches have fallen off or look dead with the exception of new growth at the very top of the tree. By now though (early june) even those healthy leaves at the very top are beginning to turn brown and look like they're in trouble like the lower part of the plant.
Here are some pictures:
Can anyone tell me if this is evidence of overwatering/underwatering, root rot, or too much light? What's funny is that altough the ends of most of the branches look burnt, the braches themselves up to endpoint look green and healty. Thank you for your help, I don't want to lose this tree!