It appears to be Lichen, not harmful but it could be growing on the tree because the tree is having some health problems. If you add more mulch, keep it from touching the tree itself. And pull back the mulch that is already there. Mulch touching the tree can be causing the tree stress which would make it susceptible to disease.
Hi Paige (I like your mama, and I'm sure you are just as friendly)! Yes, that's lichen. Not a problem in itself, but could indicate the tree isn't as happy as it should be. Why not remove the mulch temporarily, fertilize the tree lightly with a fertilizer specifically for trees, and then re-mulch as Toni suggested. Mulch right up against the bark can lead to insect damage. Mulch around trees and shrubs should be like volcanoes, with a crater!
Thanks. I do mulch that way, but I guess the mulch tends to spread out when it's been a while since the last application.
Good suggestion, Toni. Ronni isn't proud of her daughter much is she? Yes, I also agree that it is lichen. Lichens are an interesting entity. Reading about them makes for interesting reading if you are botanically inclined. That word, botanical....that is exactly where the interesting bit begins. I am not going to go into what for me would be a riveting discussion about the nature of lichens, but to lift the corner of the curtain and tell you that a lichen is actually two organisms living in symbiosis-- fungus and algae. In the past, there has been speculation that the presence of lichen on shrubs, trees and so forth was per se a sign of "unhappiness" that a the "host" plant is experiencing. I use quotation marks here because the shrub or tree is not a host in the parasitic sense, as the lichen does not penetrate deeper than the bark. The outer bark is dead. I have not found this "unhappiness theory" to be entirely true (or entirely un-true). It can is some cases reflect excessive situations in the general milieu of the bush or tree. One of these situations can be the presence of an acidic influence. I am thinking here of the soil pH, mulching or fertilizer used as well as foliar sprays. In essence, folks can place their plants under stress by over-coddling them--doing it out of a good heart, but leading to a build-up of elements that the plants cannot handle. Sort of like over-watering our house plants. --Giving them something they need (water), just too much of it. We don't mean to do it, but who hasn't done that from time to time. BTW--I am not implying here that you are over-anythinging your Acer...just illustrating a point. On a less negative note, lichens can also reflect atmospheric conditions. They are; for instance, very sensitive to poor air quality. and so when the lichens are not doing well, you can deduct that there is something wrong where your plants are growing. Excessive dryness is not too good for them either. The presence of lichens can be helpful, because they can purify the air to a degree. I have often wondered if the appearance of lichens on one's plants, garden stones and wooden benches is a sign that The air or soil conditions around the garden is not right, and so they come to do their work... not because there is a problem with the plants themselves. In theory it could have something to do with over-fertilizing plants, lawns and so forth. It is interesting to note that for every condition that is good for one sort of lichen there is a polar opposite to a different type of lichen requiring the opposite conditions. Urmmmm......I am afraid that I have waffled on a bit too long, so I would just say, don't worry about those lichens and just leave them be to do what they do.
No, I really appreciate all the info and I find it fascinating too. The folks here are all so much nicer than I've encountered on some other forums. I posted a different question somewhere else recently, just a simple newbie question about new buds on trees, and was told to chill out and stop being so anxious.. Rude! Anyways, I've noticed during our walks around the neighborhood that many of the other red maples along our street have these lichens as well. They are the sidewalk trees, put in by the builder in front of every house, and all around 2-6 years old. Most homeowners aren't doing much with those trees (even though they are responsible for them) other than maybe a decorative border and some occasional mulch, but often not even that. So whatever is causing the lichens seems to something universal in the neighborhood regardless of the care the tree receives (or lack thereof). We do mulch ours twice a year and water it during the warmer months, but haven't fertilized or done any pruning so far. It has grown really well despite not much TLC on our part.
Paige, this is the friendliest and kindest forum you'll encounter (that's why you will fit in so well). Frank, Eileen, and Toni keep it that way! Sjoerd got me to thinking (a process I rarely indulge in) and I looked up lichens. It seems they often grow when the host plant undergoes drought, or extremes in temperatures. Judging by that, Texas should be covered by lichens!
I am so glad that the nature of this website is palpable to you. That is down to two main reasons---Frank and the monitors and the members themselves. Naturally your mum is so well-liked and a good participant on here helps too, I believe. Rudeness is not something that I encounter on here. Like Jane said--when a plant is stressed for whatever reason, its system is weakened, and it will be open to a number of bad influences. It was good to hear that you find the lichen subject interesting. It makes fascinating reading (to me at any rate) hahaha. At any rate, I suspect that the presence of lichen on the trees in your street does not represent any special sort problem. I hope that you will enjoy using this website.
