Ask Mr. Smarty Plants

How do we feel about the willow? Let us count the ways.  While there are some members of the Salix (willow) native to North America, landscape willows are most often either Salix matsudana (Globe Willow) or Salix x sepulcralis (Weeping Willow). We have been asked about both trees numerous times, and we can only remind you that the Lady Bird Johnson Wildflower Center is dedicated to the growth, propagation and protection of plants native not only to North America but to the areas in which those plants grow natively. Here are extracts from two of our many answers on questions regarding these trees:

Non-native to the United States, Salix x sepulcralis is a hybrid of a Chinese species (Peking willow) and a European species (white willow), and is said to grow in Zones 5 to 8 in the United States. It is weak-wooded, fast-growing and, therefore, short-lived. It has aggressive roots, can lift sidewalks and interfere with sewer lines, often growing on soil surfaces, making a problem with mowing. It is susceptible to a number of pests and diseases, and notorious for littering the ground beneath it. You might check out this University of Florida Extension website on Weeping Willows for more information as well as this Q&A from North Dakota State University Extension on weeping willows.

Salix matsudana, Globe Willow, is a native of eastern Asia. Willows generally are fairly weak, short-lived trees, susceptible to many insects and diseases, as well as dropping a lot of litter. The globe willow is often infected with slime flux, a bacterial disease that is soil-borne.

To answer your question, you say you have recently planted your willow. The best probability is that it is suffering from transplant shock. It may have been planted in weather too hot or too cold for the exposed roots, damaged in transportation, or in the wrong soils for it. If it is putting on new buds, we would say just let the browning leaves drop off on their own.