Hi there

I need some advice. We recently had a large (three stories high) tree removed from our small courtyard which we believe was a Phytolacca dioica. We would like to plant another tree in its place asap, to screen us from a large block of apartments opposite us.

The phytolacca (pokeweed) had very soft, spongy wood. Once we removed the tree itself, we had the stump ground down. After that we then dug out a large hole about 4 feet cubed where the stump and roots were. This has been an immense amount of work, despite the soft wood! As you might imagine. I noticed the roots are soggy and stink like something decomposing... It smells awful. The hole has been open for about 2 weeks now, and we have had some rain in that time. Ive noticed that sections of the roots which had been cut open with the spades were the wood is splayed open and splintered have a fine gossamer or white moldy growth throughout. I then saw a section of root which had aphid like creatures on it, the white mold AND green mold like one sometimes sees on old bread.

I don't know much about how trees rot and decompose but I've usually only seen the wood go soft and collapse on itself. Not mold like this.

My question: is it risky to plant a new tree into this hole if so much freshly decaying root matter and mold etc is present? I'm not sure if the pokeweed roots are poisonous either.

The type of tree we wish to plant is a syzygium guineese, or water pear, which tolerates clay soils and water logged conditions. We live in Cape Town South Africa, and our courtyard is predominantly clay with a little sand.

Apologies if this is a really silly question, it's just that we were hoping to buy a really large 12-14 feet tall, (therefore expensive) tree. So it's quite an investment and we want to make sure we won't lose the new tree!

I am suspecting that the combination of such soft wood and the wet weather is helping it to decaying and decomposing like this... Like bread?

See photos below.