I transplant'ed the tree to a 3x3x3 wooden pot,I thought I was going to loose him,thank God I didnt, he finally came around and has been growing real good , except for the leaves, please help!
This article should help:
https://www.gardeningknowhow.com/edible/fruits/avocado/what-causes-avocado-leaf-burn.htm
My avocado plant is 1.5 years old. About one week ago i found that midrib of one leave was turning black. Today there are 3 leaves with black midrib,this black places become larger in size. Also there are little brown dots. Also i want to know should i clean leaves, if yes,how? Also there are spring tails in the soil and i dont know how to kill them. Please help me, i want to save my avocado plant. Thanks
Springtails won't, typically, cause any harm at all. They are beneficial to the soil.
Speaking of soil... I don't see a picture of it. The damage would indicate overwatering, but this kind of damage can occur from overfertilization, as well.
These articles will help:
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/testing-soil.htm
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/soil-ph-plants.htm
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/testing-moisture-in-plants.htm
Here is an article that will help you with the general care of the tree in container:
https://www.gardeningknowhow.com/edible/fruits/avocado/indoor-avocado-plant-care.htm
As far as spraying the leaves- I mist my indoor trees with water, or water with just a bit of aspirin in it. I do this once or twice per week, but you can do this more often if you would like.
I originally cut it back when it was 10 inches tall but it didn’t branch out then
Since it didn't work at 10 inches try it again. Go ahead and trim the central stem back about 6 inches and see if that helps.
https://www.gardeningknowhow.com/edible/fruits/avocado/why-is-my-avocado-leggy.htm
I just want the insects to stop eating my baby avocado. And advise would be appreciated and tips to keep it growing.
Sure! We have some articles that will help you, here.
https://www.gardeningknowhow.com/plant-problems/pests/pesticides/using-bacillus-thuringiensis.htm
https://www.gardeningknowhow.com/plant-problems/pests/pesticides/homemade-soap-spray.htm
https://www.gardeningknowhow.com/special/organic/eco-friendly-insect-sprays.htm
I received my cold hardy avocado today - what variety of persea americana is it? Thanks.
We do not sell plants. You will have to ask the place that you received the tree from to get information on which cultivar it is. We can, however, offer information on the care of the tree:
What should I feed it and ph of the soil?
These will tell you what you need:
https://www.gardeningknowhow.com/edible/fruits/avocado/pruning-avocado-trees.htm
https://www.gardeningknowhow.com/edible/fruits/avocado/how-to-fertilize-avocados.htm
https://www.gardeningknowhow.com/edible/fruits/avocado/avocado-tree-growing.htm
We have had exceptional heat, so I gave the avocado tree (about 2 -3 years old) extra water. The leaves look much less wilted now, but they are also yellowing. Does that mean I overwatered it, or does this just happen?
I wouldn't worry too much about this unless you begin to see more of it. The watering and heat could certainly be what caused it. https://www.gardeningknowhow.com/plant-problems/environmental/plant-leaves-turn-yellow.htm
You may need to fertilize it at some point - here's an article about that:
https://www.gardeningknowhow.com/edible/fruits/avocado/how-to-fertilize-avocados.htm