Hi all I have totally fallen in love with Japanese Maples. I moved house about 6 years ago and my new garden had a lovely, what I think is Katsura tree that is around 10 years old. I didn’t really appreciate it until my dad flew over to here to Oxford from Denman Island BC to help me with the move. He pointed out what it was and I started to admire it for myself. Over the last 6 years I have been to all the nurseries and garden centres within a 50 mile radius collecting ones that catch my eye, which is pretty much all of them and obviously that I can afford. I have one 15 year old Bloodgood in my front garden planted in the ground and the other 20 or so in containers. They range from 2 year old babies to 10-15 year old 5-6ft beauties. They give me huge amounts of pleasure. I have problem with at least 2 of my older trees. I have been looking through many of the posts on here and there is so much information to sift through that it really is quite overwhelming. I have noticed that these 2 trees have not put on any new growth over the past 2 years or so so I decided to have a closer look at them. They have what appears to be a greenish grey fungus. I will try to attach a few photos. I hope someone can help identify this and offer some advice on what to do. I do look forward to enjoying this forum and sharing my experiences with you all. Luke
Hi Luke, can I ask if your Maple is in deep shade or in too wet conditions or a confined area? If it is I think it is Lichens. As you are in England have a look at the RHS website on Algae,Lichens and moss on trees and shrubs. This will give you all the advice you need. The woodland trust is another good web site to look at. To put your mind at rest Lichens and Moss will not harm your tree. A good airflow will help. Glad you are enjoying Japanese Maples, they are addictive, we have been collecting for 40 years now and still find yet more new cultivars to buy.
Hi Acerholic and thank you very much for the reply. They are out in the sun and in quite an open area so get lots of fresh air blowing through. There is a possibility I have overwatered them though?? I will have a look at the websites you have suggested. Definitely feel relieved that it may not be something harmful. Thanks again.
I agree, lichen. Harmless. My climate is very similar to that of Oxford. It even appears every winter on my teak table and bench that sit outside in full sun year 'round, giving them a 'been-here-forever' appearance that I like a lot.
Hi, yes thanks for that. I have just had a look at Lichen on google etc. and I’m certain that’s what it is. Phew.
When they stop growing and only have foliage at the tips it usually indicates the soil is staying too wet. Drain hole could be getting clogged or the soil mix is holding too much moisture limiting oxygen. Put the pot on a stepping stone or base could help allow the pot to drain more freely. Vertical mulching can help get oxygen to the roots and curve many soil problems. A high quality organic based slow release fertilizer is great in getting more fullness and dense growth of the canopy. I have found Japanese maples appreciate such a fertilizer with beneficial microbes and rhizosphere bacteria. They are usually understory plants and their native forests are teaming with beneficial microbes from the natural breakdown of Forrest leaf litter. Our suburban lots and potting soil totally lack these microbes. And chemical fertilizer depletes the soil of any benifical microbes. I have not drawn a clear link, but I do find that these microbes improve the intensity and duration of Spring colors. They also improve overall health and disease/pest resistance. Here in the US we have PHC Roots 7-7-7 and PHC Roots healthy start available. It's the best thing that's happened to all my Japanese maples, dwarf conifers, azalea, rhododendron, bonsai, landscape, container grown maples, along with our extensive collection of dwarf perennials, hosta, ferns, and woodland perennials. I researched and tested many fertilizers over 10 years from the common chemical slow release fertilizer that are extremely popular to the stuff the professional growers use that's $100+ a bag. Also several organic fertilizers. I recommend based on experience and do not benefit in any way for my recommendation. Just sharing what works best but couldn't care less what people decide to spend their money on (I really do care about maples and want to see people successful in growing them). But based on my research I would no longer use chemical nitrogen on Japanese maples due to their high susceptibility to bacterial outbreaks, winter die back, and Summer stress. Growers use chemical forms of nitrogen because they want the largest maple in the shortest time to make the most money. They have methods of minimizing stress and the ability to provide the perfect amount of moisture and protect from seasonal extremes. This is not sustainable for the long term life of a tree, especially when planted in a natural environment outside of a nursery.
