I haven’t finished with the water droplets story yet – but I just had to add some more evidence to the tree planting discussion from last week.
Consider this series of photos below. This is a street tree in Kennewick, WA (in the southeastern part of the state, where summers can be intensely hot and dry). Every spring, this tree leafs out just fine – and every summer the leaves suffer marginal and tip scorch. This is a classic symptom of chronic drought:
As an amenity, the tree fails. Even though the landscape is well-watered, as shown by the healthy turf in the next photo, the canopy is sparse and dry.
An excavation of the roots explains why: the tree was planted too deeply and has developed a secondary set of roots:
Note how sparse these roots are – which is typical of many adventitious root systems. While the roots are adequate for water uptake during the cool spring weather, the hot dry summers suck away more water from the leaves than this puny root system can absorb, even when well-watered.
My point: sure, trees might survive being planted too deeply. But thrive? Not in this case – and this is a well-managed landscape! With less care this tree would have died long ago. The only solution here would be to replace this tree – correctly.