The other 2 trees in the clump are fine. 3) If your birch tree exhibits yellowing leaves with sparse foliage at the top of the tree, branch or twig die-back and increased side growth on lower branches; you may have a Bronze Birch Borer which is the larvae of an iridescent olive brown beetle. The affected leaves can be stunted and have browning along the edges. On April 22nd 2018, the River Birch was looking very poorly again - almost no leaves on the upper branches and the few tiny leaves that had appeared on the lower branches had brown edges and were curling. You may also find D shaped holes and ridges on the tree truck and the branches. Around the base of the tree there was a lot of dead grass - perhaps june-bug larvae had been feasting on the roots of this tree. I do not see any webbing or holes in the trunk, leaves or branches. This early defoliation can kill young trees, but most mature river birches can survive leaf spot disease. Some trees may have naturalized in the wild from yards and gardens, but several populations in New England are native, and the species is listed as rare in New Hampshire and Massachusetts. River birch is hardy, grows rapidly, but tends to be short-lived (30 to 40 years) in many urban settings, possibly due to inadequate water supply. My young river birch have brown rusty edges on some of the lower leaves. Situate the tree so it receives adequate water. The largest tree has its leaves curling up and turning brown. Facts. Birch Leafminer. The spots may be circular in shape, or they can grow large enough to create clusters across the leaves of your river birch tree. Here on the west coast it grows to a mature height and width of 40’ to 70’, developing a spreading, rounded shape. Leafminers are a common insect pest of birch trees. Without treatment, the leaves will yellow and eventually drop. River birch is widely planted for its appealing, peeling bark and shiny, diamond-shaped leaves. The tree requires an acid soil, otherwise it becomes chlorotic. Although leafminers do not kill birches, they affect the tree's aesthetics, turning the leaves brown, and weaken the tree's ability to withstand an attack by bronze birch borers or survive extreme environmental conditions. The buds have since opened, the tree did its dangly birch flower thing, and the tree filled in with leaves. Q: I have a river birch that has 3 trees (clumps) together. River birch tolerates low soil oxygen, flooding, and clay soil, but needs moist conditions. I cut a few of the bottom branches off anyway to promote vertical growth, so that should get rid of a lot of the infected leaves. Shiloh Splash river birch (Betula nigra 'Shiloh Splash'): A compact form growing 10 feet high and 8 feet wide. It bears leaves 1.5”–3” long leaves which are simple, ovate, and arranged alternately on the stems. It looks like a fungal infection, probably from the humid weather (and made worse when I water the lawn in the evening after work). The foliage is variegated and has cream or ivory edges. River birch is native to the eastern United States growing from the northeast states, south to Florida and west to Minnesota. Heritage® river birch (Betula nigra ‘Cully’): Larger, glossy, dark green leaves, nearly white interior peeling bark, more heat tolerant. While mowing the grass today I noticed that a lot of the leaves were turning brown. I planted a clump of three river birches a little over a month ago. Trees grown near driveways or patios with a limestone base that is alkaline can be affected as the roots grow into the base. When the trees went into the ground they all had buds.