Thank you so much everyone for your suggestions about how to restore the tree to health. And Leila, thank you for the welcome
In case it's helpful, my location is in the south Bay Area, Northern California in a suburban residential area. And my guess as to the species is (I think) the same as Leila guessed on Wikipedia - Liriodendron tulipifera, based on images of the flower and leaves. It is about two stories tall, and my best guess on its age based on the history of previous homeowners is that it is 40 years old. As for our climate, it is usually dry and hot in summertime, and it reaches 100F for a few days. Winters are mild, rarely colder than 30F. Winters and springs are wet and rainy.
1) A few years ago, my husband and I stopped maintaining and watering the lawn, telling ourselves, "let's just allow this land to be the way it's suppoesed to be." Whenever we saw a dandelion, we told ourselves, "Well that's what's supposed to grow here." And when the ground became hard and dusty, we said, "That's what the ground would usually look like in this climate." And now we are pretty attached to this tree so we are faced with a major decision whether to support this tree and give it the nourishment it needs, even if it means replicating another climate. We also want to make a balanced decision, taking into account human preferences, but also the health of the local wildlife, including birds, insects, microrganisms, etc. I know what the humans prefer but I'm not very attuned to the environment around here and don't know how to read this. I have so many questions: How does it impact the local environment to have a non-native shade tree in it? Or the same tree being there but no longer being watered? Or the same tree being infested? Or removed? Is there any scenario where it would be best to do nothing and allow the infestation and water stress to continue, and not intervene? Any wild guesses as to what would most benefit the surrounding environment? (I'm telling myself that the aphids and scale have a right to eat too. But then my understanding of all of this is so incomplete.) Does permaculture philosophy inform this -- decisions when tweaking an already established urban residential environment? Or could I be misunderstanding permaculture, maybe it is more for designing new sustainable systems from scratch? Is there any principle I can draw on like, it is usually most beneficial to support mature landscaping in urban environments because, most likely, the ecosystem has already changed to support it? Or anything like that? Hmmm ... Maybe I've misunderstood permaculture completely?
2) I'm very new to all of this and I wasn't familiar with the word dripline Leila mentioned. I read up on it and I realized that the canopy of the tree covers almost the whole yard, and the rest of our property is covered in concrete. Some sources I read said that the roots within the dripline are for support, and those outside of it are for absorbing water. Would you all agree? If yes, what might that mean for the long-term health of the tree? Will it be able to grow and keep absorbing water with all the concrete around? (Is its health going to be sustainable, or if I help it through this infestation, is it just postponing the inevitable?)
3) Finally, I have sought the advice of a local Master Gardener. Would anyone happen to know if the Master Gardener program (I think it is nationwide in the US) is informed by permaculture principles?
Thank you all for reading my questions and for your patience as I try to understand permaculture. I welcome any insight ...
Patty
