I don’t have my books handy, but while they take a lot back this varies by species and the fallen leaves can have a lot of N and P in some cases.
Though I’ve always seen them shredded and used for making compost anyway rather than leaving them on the ground. Too easy to get rot that way.
And you really want to spread them around the rest of the garden if you’ve planted trees that do drop N in the leaves
I’m sure it does vary—my impression is that N fixing trees in particular are going to have higher N levels in the leaves they drop but I’m sure it varies by species as well.
But from my experience, most urban shade trees don’t really need to be fertilized unless they are exhibiting symptoms of nutrient deficiency—and even then, this is often a symptom of poor soil and root health overall more than a specific lack of a nutrient. Most urban soils tend to be fairly high in nutrients due to air pollutants, excess fertilizers, pet feces, etc. I’m sure this can also vary by soil type and climate, but it’s true in most areas I’m familiar with.
No I agree, it’s mostly useful to fertilize the plants elsewhere in the garden.
But it seems everyone here is thinking of lawns and I realise late my concept of a garden is utterly alien to what most people actually do. No lawns for me!
I don’t have my books handy, but while they take a lot back this varies by species and the fallen leaves can have a lot of N and P in some cases.
Though I’ve always seen them shredded and used for making compost anyway rather than leaving them on the ground. Too easy to get rot that way. And you really want to spread them around the rest of the garden if you’ve planted trees that do drop N in the leaves
I’m sure it does vary—my impression is that N fixing trees in particular are going to have higher N levels in the leaves they drop but I’m sure it varies by species as well.
But from my experience, most urban shade trees don’t really need to be fertilized unless they are exhibiting symptoms of nutrient deficiency—and even then, this is often a symptom of poor soil and root health overall more than a specific lack of a nutrient. Most urban soils tend to be fairly high in nutrients due to air pollutants, excess fertilizers, pet feces, etc. I’m sure this can also vary by soil type and climate, but it’s true in most areas I’m familiar with.
No I agree, it’s mostly useful to fertilize the plants elsewhere in the garden.
But it seems everyone here is thinking of lawns and I realise late my concept of a garden is utterly alien to what most people actually do. No lawns for me!