Lemon tree yellow leaves

Hi Can anyone help me with my Lemon tree.
It’s 3/4 years old.
The leaves have been yellow for a long time but unsure how to cure it.
I feel it weekly with a citrus feed but nothing seems to change.
I also have a Meyer Lemon tree and kumquat tree which have similar vaining but remain a good colour green.

How big is the pot it's in?

My lemon tree responded well to additional potassium, but I've read lemons don't like alot of fertilizing to begin with I got just potassium in powder form by a company called RAW. They make all sorts of great single nutrients, and a few combinations. This link is to the Amazon page showing many of the options. https://smile.amazon.com/s?k=raw+nutrients&crid=2CRAM2C8POMFL&sprefix=raw+nutrients%2Caps%2C242&ref=nb_sb_ss_ac-o-p_4_13   The 2 ounce size is plenty for several uses on several plants/trees. I've used some on my bananas too, hoping that the increase will get my baby bananas to a stage that they can be eaten. And my lemon tree leaves got better too!  Another possibility ( I've not researched this for your case) could be too much fertilizer. Just something to think about. Good luck!

George Yacus wrote:How big is the pot it's in?

It’s a 5 Litre pot.
I potted it up in March 19 using citrus potting mix

Cindy Haskin wrote:My lemon tree responded well to additional potassium, but I've read lemons don't like alot of fertilizing to begin with I got just potassium in powder form by a company called RAW. They make all sorts of great single nutrients, and a few combinations. This link is to the Amazon page showing many of the options. https://smile.amazon.com/s?k=raw+nutrients&crid=2CRAM2C8POMFL&sprefix=raw+nutrients%2Caps%2C242&ref=nb_sb_ss_ac-o-p_4_13   The 2 ounce size is plenty for several uses on several plants/trees. I've used some on my bananas too, hoping that the increase will get my baby bananas to a stage that they can be eaten. And my lemon tree leaves got better too!  Another possibility ( I've not researched this for your case) could be too much fertilizer. Just something to think about. Good luck!

Brilliant thank you

It looks like you need to give the lemon tree some Epsom salts. That’ll green it up.

A rule of thumb...if something happens to the edges of the leaves ithen the source of the problem is most likely being taken up from the soil/roots.  It does appear to me from the photos that the edges of your leaves yellowed more/ prior to the interior of the leaves?  

I would research a bit more about lemon trees from a variety of sources and re consider appropriate soil; ph and fertilizer if my o serration is correct.