Yes. I'd make a clean cut with a saw. Deformed roots due to careless container production is pandemic where I live, not limited to clump birch trees by any means. Even field-grown stock often has them, due to the plants being grown (too long) in small pots before being planted out in fields.

Jaansu, What is the model of the sprinkler head?

That root you see is most likely seeking the moisture, which the mulch is holding. Three years ago, I planted three single trunked Heritage river birch trees in an area which sometimes gets flooded to an about 4 inch depth whenever the area experiences frequent rain periods. In the hot humid summers the soil dries out well. The Soil is a silty loam, and when I planted these trees I found that the soil had been hard packed by the frequent yearly flooding. The planting turned out to be a lot of work because of the effort it took to dig that hard of soil. This was especially hard since at the same time I installed 5 "T" stakes for keeping the wind from whipping the young trees and tearing their roots. This is on a vacant, slightly larger than half acre residential lot. That means any watering I give any of the trees I plant on that lot has to be trucked there. For this reason, I have not supplimental watered these riverbirch trees. Still, during the last three years, I have never seen any surface roots, growing from these birch trees, along the surface of the soil. Three years ago I could not find any clumped Heritage birch trees at any of my local nurseries. And many of my local nurseries did not have any birch trees for sale. The nursery owners, at that time, told me that the demand for birch trees had drastically decreased, so it was no longer affordable to stock birch trees. The reason for this decreased customer demand? Several nursery owners told me that customers found out that roots from birch trees they had planted did too much damage to their sidewalks and other concrete structures. Even though no nursery would sell me a 10-15 gallon sized clumped Heritage River birch, I still wanted that tree for this area on my lot where no concrete or asphalt stuctures would ever need to be installed near enough for the roots to damage. That is why, once I found a nursery who had 3 gallon sized potted single trunked Heritage birches for sale, I purchased three of them and planted them in a triangle about 2 feet apart. Since planting, our area has encountered a couple very dry and hot years with drastic sudden drop and rising of temps during those year's winters. We even experienced one winter event where light rain fell off and on for three days in 28-32 degree temps. This created heavy layers of damaging ice on the local trees' branches and even trunks. Many of these trees suffered massive branch failure, and some on some of the trees in the area, their main leader trunks even snapped off. Last winter when I checked my property for ice damage, I found that my Heritage birch trees needed to have a few broken branches pruned away. After pruning they looked quite bare. This years' growing season has turned out to be one of the wettest years I can remember occuring locally. So now those well established birch trees have recovered and look the strongest I have have ever seen them. Even with all the stress my trees have encountered, they still are not showing any signs of growing surface roots. I do not know why. Maybe it could be due to fact that, after the breakdown of the first application of mulch I gave them, I never reapplied any mulch under these birch trees. The only reason I have been able to get away with not continuing to mulch them might be because, growing nearby my birch trees on the neighboring property, there is a multi-trunked pecan tree, which provides afternoon shade for them.

Well, asian jasmine is a pretty tough ground cover if you want something with small glossy leaves. It takes it 2 or 3 years to get established really well in clay, but once it is well established, it crowds out anything else that tries to move in. I had it in black gumbo clay in Fort Worth for years and years. It was under a big old oak tree at the back corner of the yard and it got morning sun until about noon, then shade all afternoon, and late afternoon sun from 5 p.m. on. I didn't improve the soil, I didn't mulch it and it had to make do on rainwater after the first year. Last year, I made some lists of plants that do well in clay soil for Emily. I've linked the ground cover list below. Not all of them would work in your location, but I think many of them would. Any of them probably would need irrigation for the first year or so to help them become well-established. And, by the way, the toughest groundcover we have in our red clay soil here in the woods under tons and tons of mature trees is Virginia Creeper. It is not evergreen and it mostly creeps on the ground, but will climb trees and walls if it gets the chance. It is, though, able to go with the flow and handle everything from prolonged drought to flooding rains once it is well-established. When you have really dense tree roots, often shrubby or vine-type ground covers do really well there. Also, plants with really large bulb or tuber type roots can compete well with dense tree roots. Among those type are cannas (they won't die and you can't kill them, but they aren't evergreen) and four o'clocks (their root tubers get bigger every year...I have some in my narrow band of sandy soil that have tuberous bulbs as big as my head). In clay, under tree and shrub roots, I have purple winter creeper in clay soil that stays so dry in the summer that it cracks. In similar soil (pH of 6.8) I also have virginia creeper, trumpet creeper, several types of creeping junipers and liriope. Dawn Here is a link that might be useful: Ground Covers for Clay Soil