I've been using fallen leaves for mulch around my JM. Now I've read that it might not be a good idea to use leaves as mulch as they can harbor disease and fungus. Thoughts? When the leaves are dry and crispy I crunch them up until they dissolve into tiny bits of pieces. When they are wet and soggy (ie in the fall/winter) I shred them up and further cut them with bypass pruners. I try to make them as small as possible so they degrade as fast as possible. Also I'm not sure if some types of leaves maybe harmful as mulch. The leaves that I've used include the following: japanese maples, maples (the large ones, not sure of the species), japanese cherries (prunus species), rhododendron, kousa dogwood, tulips, lavender, osterspermum, etc. I've also used grass clippings and clippings from prunning cuts to the JM. This is added in conjunction to the pine bark nuggets I use as mulch. Please let me know if I should not use any of the above as mulch. Any comments are appreciated! Thanks
Ok,I admit I consider myself as a relative newbie to maples and am always learning more here.However as a relative newbie I do sometimes have opinions which can be disputed,but I have to put them forward to find out more. We may all have been gardening for years&years,growing all sorts of plants and shrubs,applying common garden practices and common sense with good results.However when getting into the wonderful world of JMs, I at least start acting rather strangely and doubting all that has gone before. I'm sure we commonly go about our gardens adding compost,mulch,leaves,a little fertiliser here and there,I don't see any reason why to treat the Jm any differently.After all it is another woody plant which I'm sure,like many others we grow just requires a well drained medium.The only 'finicky' requirement I see is the sheltered positioning sometimes required. If you didn't sweep up the leaves,where would they be?...I'm sure if you went into a maple forrest(haven't got them here)you'd see a vast carpet of leaves.Sure there'll be a lot of fungus and perhaps some diseases in there,but it is natures way of recycling.There are some species of plants that have leaves that inhibit growth of competing plants,I don't know if any are included here but I don't think they have much effect on already established plants. I do feel that a lot of the worries we have and read about on the web are more to do with container culture,which does require closer monitoring.I also wonder at times if we should step back and look at what we're doing to our maples.Could it be that many of the cultivars,and many of our maples have spent their whole lives in the relatively sterile container world,and are losing their resistance to any stress and diseases.We are now asking ourselves this about our own offspring.It has been mentioned here that all Jms have verticillium,and I'm not about to dispute that.Infact I feel that it may be a good thing,and if kept under control will give the plant at least some resistance to the disease. Sorry I've gone a little off track there,but I had to get it off my chest :)
Chopped leaves make for great mulch - I like oak leaves because they breakdown very slowly, but maple leaves (and many others) are very good as well. As you pointed out there are some genera whose leaves are unsuitable. Walnut trees produce a substance known as juglone which creates an allelopathic relationship with some plants. Silver maples are sensitive to juglone, but most other maples are listed as "not sensitve." In any event, I'd never use walnut leaves for mulch on any plant. Also, I'd leave-out the grass clippings. They are very high in nitrogen and will tend heat up as they begin to compost. They're also mat-forming and will retard water infiltration.
I'd also thought I'd post a pic of my mulch. You can also notice that it's a Sango Kaku. One of the thing about using leaves is that I often find slugs underneath them.
I have masses of leaves every year and have an abundance of leaf mould as a result. It makes for a great mulch. Only problem can be the need to continually pull out the new 'trees' trying to grow.......
I am an organic gardener and don't use any synthetic fertilizers in my garden. I consider them harmful in the long run. To make my soil fertile I use all kinds of organic mulches. If I were you, I would rather worry about the area outside of the mulched circle. The mulch inside the circle provides food and shelter for the soil organisms that make the soil fertile (see kootenaygardening.com/soil_organisms.htm) . There is not much for them outside the circle. As a minimum, I would at least leave the grass clippings on the lawn. As for pine bark nuggets, are you sure they are not treated with anything that could be harmful to your tree? I use wood and bark chips too, but am very careful where I am getting them from. In any case, if you will have any problems with your tree, it would not be because of the mulch you use, unless it contains herbicides or some other harmful substances.
The only problem I have with the leaves is that sometimes they can get really deep around a maple or anything else. Then I have problems with voles and moles digging around all winter long and sometimes find bark eaten by other little "beasties" that live around. We have the woods all around us and you can really get a deep blanket of leaves. Chopped up they are a wonderful mulch, but I usually don't have time in the fall to do that. I try to leave some leaves, but rake where the leaves are really deep or where I see a lot of mole runs, or other activity. If the cover isn't too deep, I'm hoping they will be prey for an owl, hawk, or whatever. Kay