Thanks for the compliment. I do have multi-plant photos of the Moon Garden in the database, but not this one. (I really don't want to submit anything with those dratted landscaping flags in there!)
Re the root rot, I don't think the soil was soggy, so much. While there *was* irrigation in the area (both by previous owners and by us), the oak was sitting at the top of a creek bank (so it had drainage) and we tried to avoid spraying water on the oak. The tree did have some sort of beetle infestation in the past (for all I know, still did/does, as a woodpecker went after it earlier this year) and that may have contributed to the ruin as well.
We live on almost one acre, and there are many old oak trees on the property, and most of them are in decline. (When we bought the property, there was already one large, old dead oak that we had to remove ($$$
), and another that shortly succumbed to root rot.) Partly (if I understand our arborist right) it is a matter of age, partly it is a matter of changing environment over the years. Apart from different owners and different irrigation situations, the city of San Jose did some flood abatement work several years ago which (we hypothesize; we do not live near where that work was done) somehow resulted in a net lowering of the water level in *our* "creek" (actually, officially, a drainage ditch, though one that is natural looking (no concrete) and functioning (lots of little critters live there - crayfish, small fish, frogs)). Once that happened, the oaks along the creek really started heading into a decline, so our arborist thinks that lack of (relative) seasonal flooding may have something to do with it. (There is also the question of what chemicals might be in this "drainage ditch"; we think that people upstream are, at a minimum, washing their swimming pool water into it (from sporadic rises in the water during the drought season), and there is always the question of fertilizer and pesticide/herbicide runoff.)
Last fall we planted out several oak seedlings (we have lots of volunteers, from both the oaks and a Japanese maple grove) on the lower creek banks, to start a succession. We will do that again this fall.
It does seem like the rot is in the soil, though. (That is what got our beautiful corkscrew willow a couple of years ago.) That makes me question the wisdom of replanting trees that are susceptible to it (the willow was replaced with a native maple), but our city is oak crazy and I won't be surprised if they demand that we replant with one or more larger (than the seedlings) oaks. (Been there, done that.)
We *do* have some healthy oaks on the property, just not along the creek banks. (Well, we have a deciduous oak there that was thus far doing okay, though I noticed some die back on one limb the other day.) We have a nice blue oak in one corner of the property, but I fear for that tree - not because of root rot, but because on the hillside above it is a large eucalyptus. That monster just dropped a huge limb a couple of weeks ago (the owners have left it lying there), and I fear if the rest of that thing goes, it is poised to come crashing down on top of our fence and the blue oak.
Before owning this property, I would never have believed all of the trials and tribulations (and arborist costs!) that having several trees could mean.
