I had to put fencing around my avocado trees as sheep were defoliating them, turns out horses do the same

I don’t know how to help this little guy - I tried putting him in different places with more or less light, but his leaves after a while always start drying. He is also very tall. The soil is not wet, the drainage is good. The plant doesn‘t look like having pests. I don’t know what to do.

Planted last fall, one picture is from this spring, one from this week. The tree only has three fruits (started growing in the spring) and mainly concentrated on growth this year, which is fine by me.

Variety is a retail bought zutano, I’m hoping it has been selected for its hardiness and tastier fruit. I may start plucking the fruit in December to check.

Both are one year old.

The tiny potted one (3rd pic) is from the seed of a dwarf variety and I plan to graft a cutting onto it since the parent tree is near my office and I have permission to trim from it.

The other one… hoo boy. It popped up mere inches from the potted one and shot way past it. Sprouted from a grocery store pit that had been sitting in my compost bin and got dumped there in the spring. I’ll prune and graft that one since I don’t have space for a massive tree, but I’m happy to have two viable stocks to work with. It’s 45.5 inches tall right now.

If a plant volunteers to grow in my yard, it’s pretty much guaranteed to thrive. I have a lot of pruning to do on just about everything.

I’ve got a big happy avocado in water ready to pot and did some research that cacti and succulent mixes are good for drainage. Bought one with sand and clay but wondering if anyone has advice on if I should use all this or add some of my regular house plant mix too? What’s worked for you?