I have an avocado tree that is just under a year old (grown from the pit of one delicious avocado!). I pruned it about 4 or 5 months ago so that it would branch out. That worked out well enough, except that the new leaves on those branches are significantly lighter than the old leaves. At first I thought they would darken, but that has not happened.

A friend of mine suggested moving it to a sunnier spot, which I did... that still didn't help. And now the edges of the leaves are browning although it gets plenty of water. The only thought I have left would be that the container is too small... but I hardly think that a 50+ liter (15 gallon) container would already be too small for a meter high tree. What do you think?

Looks like a mineral deficiency of some kind to me.

Dr. Google suggests pale yellow new growth could be a symptom of sulfur deficiency.

It might be the taproot outgrowing the pot, either way I would transplant it into the ground.

Yellow leaves with green veins can indicate iron deficiency/iron chlorosis- starts on new growth and eventually spreads to older growth, if severe enough the edges of the leaves then turn brown as the cells die. Iron deficiency stops the plant manufacturing chlorophyll- hence it stops being green.

Fastest way to fix is a foliar spray- such as a good compost tea or seaweed solution.

Charli Wilson wrote:Yellow leaves with green veins can indicate iron deficiency/iron chlorosis

Thanks @Charli, I think that's the best diagnosis so far. If you look a the picture of the darker green leaf, you'll see that it's starting to grow faintly yellow as well. @Roberta may be right as well with the sulfur deficiency. I saw both suggestions in my searching, as well as a suggestion to check the soil pH, so I'm waiting on a soil test kit to come in to test everything. But in the meantime, I'll head to a garden store to see what they have that I can use to give my tree some iron and see how that helps.

@Bengi I've been reluctant to transplant it because I don't have enough soil in my yard (mostly concrete, unfortunately), and my (future) food forest is pretty far away. Until I am sure that someone that can take care of the transplant, this tree, and my beautiful fig tree, will have to stay with me.

You have access to seawater? It has every mineral that exists. Dilute 10 parts water to one part seawater. Water the tree with it. Whatever is deficient will be in there.

wayne fajkus wrote:You have access to seawater? It has every mineral that exists. Dilute 10 parts water to one part seawater. Water the tree with it. Whatever is deficient will be in there.

Hmmm... Never tried that for anything. Thanks for an "excuse" to make a weekend trip to the beach .

Joseph Bataille wrote:

wayne fajkus wrote:You have access to seawater? It has every mineral that exists. Dilute 10 parts water to one part seawater. Water the tree with it. Whatever is deficient will be in there.

Hmmm... Never tried that for anything. Thanks for an "excuse" to make a weekend trip to the beach .

Is 10:1 diluted enough? Salt is NOT a good thing for most plants.

Sea minerals are wonderful for plants. The 10:1 ratio works very well for trees, veggies and shrubs.
Commonly, many people veer away from salt water use for plants but 30 years of research shows it is not as detrimental as common thought patterns think.

Sea-90 is sea salt with all the minerals, this has been applied to fields at the rate of 2.5 tons per acre for three years and the only thing that happened is that the plants grown grew better, were far healthier and tasted better than the control fields crops.
I use this stuff on all my fruit trees and my squash and tomatoes, it only takes about 1/2 cup for a tree (per year) and I use a table spoon for each vegetable plant, just sprinkle it around the drip line.
I also use it as the source for free choice minerals for our guinea hogs, dogs, chooks and as we get more animals, they too will have a free choice bin of sea-90.
It works great in our salt grinder on the dinner table too.

By the way, I'm not a distributor, just a user of the product.
I don't think it will be detrimental to our plants, so far my own experiments are all with positive results.
I use it on fig trees, pear trees, plum trees, mulberry trees, apple trees, squashes, onions, beets, and will be testing it on pumpkins and all our other veggies next spring.
It is not a "fertilizer" just a mineral supplement that we started using last year and were amazed at the results we got.
Soil testing is a recommendation since you don't want to get your soil out of balance if you can keep from it.

With all the regenerative abilities of earth, the ocean is the one that stumps me. It accumulates minerals constantly but never gives it back, at the expense of mineral depletion upland. So putting it back makes sense. For the earth to do it for us, we'd be looking at animals 2x2 loaded in an ark.

I found this article after a quick search. It has a cool chart that details the trace minerals found in seawater. It also makes a claim that the land that got hit by the 2004 tsunami in South East Asia experienced 2 years of bumper crops. @Wayne, maybe that's one way the earth gets some of those minerals back... That and coastal winds blowing ocean sprays...

wayne fajkus wrote:With all the regenerative abilities of earth, the ocean is the one that stumps me. It accumulates minerals constantly but never gives it back, at the expense of mineral depletion upland. So putting it back makes sense. For the earth to do it for us, we'd be looking at animals 2x2 loaded in an ark.

I was reading on volcanoes and randomly thought of your post... Strange I know, but when I realized that every eruption brings tons of minerals and gasses to the surface, I began to wonder if maybe volcanoes might have the ability to replenish the earth with what the ocean takes from it... Just a thought. Might wanna build a fireproof ark next time.

It might be iron lacking......in Citrus is very common, but it happens in all kind of plants !! Use microelements enriched in Iron, water only when the upper soil is dried..