The soil is very hard and I have to usually use a pick and a shovel to break through the layers when digging. When i was surface watering it would not seep through very well. The core of the root ball was about 1 foot below the surface when planted 3 years ago and I'm watering from 2-3 feet down until the water level rises back to the top because I was recommended the deep root stakes as it encourages root growth downwards where the water tends to remain longer during summer months and because the hard clay soil tends to spread water outwards rather than down like loose or sandy soil. I was told these trees need a lot of water but infrequently so I'm putting about 40 gallon worth per tree every month but I don't know how much is actually reaching the roots. I'll buy the chelated iron asap and dig to see soil mosture content 1-2ft deep. If it turns out to be over-watering can the trees survive and what can I do other than just wait before the next watering cycle?

That's why I love plants, all they need is a little water, food and a lot of sun. Don't create much of a fuss. I'm a bit of a misanthrope haha. Plants are good company.

Hi Lisa and John First thank you for helping me out. The soil is 1 year old (I've moved her into a much bigger pot in June), but I think it's of wrong type (will fix this tomorrow). I didn't fertilize through the winter, but have started lightly one month ago with a German bio fertilizer (Bio-Zitruspflanzendünger). I've also looked at the bottom of the leaves as you asked and on some leaves have brown spots. Now as branches had these when I bought it I fought that it was part of the tree. Now if I use my nails on the brown spots they get off very easily. Are bugs attacking my plant? Brown spots. Removed the brown spots from the branch. Br Waldemar

Your tree still looks quite healthy. The yellowing at the leaf tips is most likely from the soluble salt levels increasing in the root zone. Every time you fertilize you build up salts. Periodic flushing with clear water washes them away. Have you every flushed the soil with clear water to wash out the salts?