I would stop with the urine because the bacteria in the soil may convert the urea into ammonia which increases the pH which citrus do not like because they like acidic (lower) pH. High pH prevents them from taking up nutrients which leads to nutrient deficiencies which your trees definitely have as evidenced by the light green leaves. This may not be the sole cause of the deficieny but I would discontinue the urine treatment regardless.

I also suspect that the nutrient deficiency of the plants in the ground is a root problem which leads me to ask you to give me the details of exactly how you planted the trees.

The kumquat in the container: the yellow leaves are old leaves which have served their purpose and the plant is about to get rid of them. Nothing to worry about. It's perfectly natural.

The trees were removed from the soil, where they had been happy and flourishing for a couple years, put in large pots for around month, where they stayed happy and lush, while the soil level was lowered by a few inches and leveled. Then a couple inches of compost was tilled in, and the trees were put back in their same spots. They're planted on slight mounds. They were put back in the ground the exact same way as they had been before, basically just put them in. The first time I planted them the top few inches of soil were amended with special citrus soil from home depot about 5 feet in all directions from the trunk. I didn't amend them after transplant because the compost was tilled in. The compost was redwood and manure, and everything else seems happy in it. I have lots of stone fruit trees as well and none of those have had any problems with transplanting, just the citrus. The injury to these trees came basically immediately after transplant.

I used the urine mostly on that lemon and the results were great, it was much yellower before! The other trees get it sometimes but not much and not regularly. Urine was applied only after these symptoms had been present for about a month. I quit when I got tired of collecting it.

Glad to hear the potted kumquat is ok!

I have a ph meter but I think it's broken. I'll definitely check the ph!! If it is alkaline, how do I fix that? I think it's strange that they would be so unhappy when they are in virtually the same soil, in the same spots that they previously flourished!

This may be helpful: https://puyallup.wsu.edu/wp-content/uploads/sites/403/2015/03/soil-amendments.pdf

If you want to use urine. Grow figs. It works great on figs.

Tristan if you do use urine on your figs as poncirusguy suggests, please don't offer any fruit to me.

Poncirusguy, I do grow figs! Thanks for the tip!

A lot of other forums advocate diluted urine as a fertilizer, is that wrong? Is it harmful to citrus trees?

Silica, im guessing these trees are 3 or 4 years old. last year they all fruited a little, maybe their age can be inferred from that. If I fertilized 1 month ago, given their state, when should I next fertilize? And what should I use? Will anything labaled "citrus" work ok? Or is there an optimal NPK I'm looking for?

Do you have to fertilize mature trees? We have a large orange that came with the house that hasn't been fertilized in years, but it looks healthy and every year it gives us hundreds and hundreds of oranges.

If your trees are indeed 3 or 4 year old a 3 year old tree should be fertilized 4 time /yr. After a citrus tree reaches 4 years of age the tree should be fertilized three times per year thereafter. For trees four years and older the three application can be spaced two months apart. For in ground trees you have a rather wide range of fertilizer to use. Find one that has higher nitrogen and potassium and that also has trace minerals. It is great that your orange tree is supplying you with fruit, however it should be fertilized. The best to you and your trees.

They are simply under nourished. Perhaps the pH of your soil is too high and/or the pH of your water is too high... either of which will prevent your trees from getting the nutrients they need; this is especially true of Iron. You can try chelated iron which commercial growers use if their soil or water is above pH 7.5.

I use Iron and the urine is used in the dirt for my fig trees. I eat all my fig,