Help me with my birch tree

[enrique.dv]

Hello everyone, Im new in this forum and I hope you can help me!!
to put this into context, I live in La Serena, a coastal town with a maximum temperature of 23°C in summer and a minimum of 5°C in winter.
A few years ago (2022) I planted a 4 mts tall birch tree in my front yard, which recieves direct sunlight all day. I prepared the soil the best as I could adding earthworm humus and coconut fiber to it and watered the tree three times a week. The first summer, I noticed that the three leaves started to turn yellow, when all of the birch trees in the city were stil full of green leaves. Short story, it died the next summer.

Now I bought a smaller one (3 mts), but now I considered to plant it at the correct height, where the root flare sits slightly above ground, also tried to plant some bushes around it (obviously keeping a distance from the trunk), put a layer of mulch on top of the soil to keep the moisture and controlled the watering schedule, but the leaves are turning yellow again.
What am I doing wrong?

 

[cpp gardener]

Maybe some pictures would help.
When did you first notice something was going wrong?
Was it an unusually warm, dry Summer? Did it rain a lot?

 

[enrique.dv]

I will upload a picture

Maybe some pictures would help.
When did you first notice something was going wrong?
Was it an unusually warm, dry Summer? Did it rain a lot?

I just took some pictures. Also I forgot to mention that the first bitch that I planted developed ZERO roots, nothing new grew from the rootbread, so I just lifted the trunk up and the whole dead tree came up without effort... and I just noticed that the same is happening with the new one, I thought that was due to excessive watering but I always try to be careful with watering

 

[Anniekay]

You only water trees and bushes, for the first year, ONCE a week. The top of the soil needs to dry out. Overwatering will cause leaves to yellow and fall off. Do not plant the tree high, plant it at the exact same level as in the pot and water once weekly. Stake the tree so that the wind won blow it over but the canopy can still sway in the wind so that the tree strengthens itself from wind.

 

[cpp gardener]

So, how often do you water it?
By hand or with an irrigation system?
If a system, how long does it run?
If by hand, how much per watering?

 

[Thame Gardener]

We used similar to the link below when we planted our 4 pleached birches which our now 11 years old

Mona Relief 1.25m

Mona Relief Tree Irrigation watering systems are an essential tool to guarantee the success of urban planted trees and shrubs. Lack of water at the tree's root ball can be detrimental to the lifespan and survival of the tree.

marshallsgarden.com