Like most birches, "Whitespire" does have a preference for slightly to moderately acid soil. River birch is the birch species with the greatest need for low pH. Use the diagnostic hint supplied by heptacodium, as well as a soil test, to determine this. If you do end up wanting to adjust the pH downward, my recomnmendation is to use soil sulfur. This granular form can be simply spread on the soil surface. If you have the tree(s) in a mulch bed, you may be able to work some of the material into the mulch, but otherwise, don't worry about that. Sulfur is slowly converted into sulfuric acid by bacteria in the soil. This of course, brings dowwn the pH. Because it is a slow process, it can also be fairly long-lasting. But, in the long run, due to their buffering capacity, soils will tend to return to their former condition eventually. Still, as I always say, for a few trees in your yard, it is a simple matter to reapply a few years down the road. Birch are funny trees in that, when grown in peoples yards, they can seem finicky as to their requirements, while in nature, they get along easily. On my land, I've got lots of paper birch which BTW, is a far superior tree to Whitespire, IMO, and they do just fine. There are young saplings coming up in sunny openings all over the place. Good luck.......+oM

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.

Enclyclopaedia Botanica describes Whitespire as a "cultivar of very upright growth with clean white bark". From the photos I've seen it is quite unlike the weeping birch we are probably more used to seeing - much more upright, pyramid shape and, in mature trees, a multi-trunked appearance. The larger leaves are probably just a feature of new growth.

If rocks of any size are touching the root crown or buttress roots they may presents problems over an extended period of time, as the rocks retain excessive moisture. This excessive moisture is just the environment fungi, bacteria, and mold are looking for. The root crown flare should be exposed and not covered with rocks, wood mulch, plants, or anything else. The large rocks around the white birch look pretty good, but the city owned tree root crown is totally covered in a mound of rocks. Rocks and wood mulch incorporated together would be fine. Wood mulch by itself works too. Just expose that root flare and do what you think looks best. I personally prefer wood mulch, fallen leaves and stems, as it mimics what we see naturally. The 5-6' from the tree base is just a general guideline. The closer you get to the base of the tree, the larger and more important the root structures become. Driving a shovel near the base of the tree to create a planting hole can have consequences to the lifespan and health of the tree if large roots are cut. If you don't want to severely shorten the lifespan of the white birch, do not cut one of the four main trunks. This will do little to reduce the size of the root system and will surely kill the whole tree sooner than later.