(Question)
For a tree which has an oval drip line with a 5 foot diameter, I added 26 kg of city compost. Is the reason one shouldn’t add shredded mulch that the mulch will smother the compost living matter? I guess that sort of mulch is ideal for a weedy area around flowers.
(Answer)
Thanks for contacting us again concerning composting and mulching your neighbour’s Beech tree. In your first question sent May 15 of this year, you asked if you should not add shredded mulch over the compost you have already added.
You may add mulch if you wish. It really doesn’t matter what form the mulch takes. Shredded mulch is often Cedar mulch (with a blend of other woods) but it could also be shredded leaves. Shredded mulches stay in place more easily than non-shredded especially in wet situations. They are often used in garden beds. Non-shredded mulch could be from the bark of trees or woodchips from lumber processing. Bark mulch, or pine nuggets usually have bigger particles and are often recommended for trees as they take longer to break down, thus they don’t need replacing as often. In all cases you should lightly cover the composted area with the mulch of your choice (around 3-5 cm) as you want the tree to be able to absorb water and air easily. And remember to keep mulch away from tree trunk.
You are correct that too much mulch may inhibit the speed in which the compost underneath breaks down. In the answer we gave you in November 2021, we suggested that mulching could occur over the compost after the ground is frozen. But you can add mulch now if it is convenient for you. We may have sent you previously this link to an interesting article about mulching mulching.
I hope this answers your question. I will answer your second question in a separate response. Best luck.