Potted Salix has only produced leaves at the end of the stems so far this year

Question

I was given a potted salix last year and it grew well. So far this year, only the ends of the stems have leaves (probably about 25% of the length of the stems). There are nubs along the stems where I would expect the rest of the growth to appear, but no sign of anything further. I topped up with compost a couple of weeks ago. Am I being impatient, or do I need to do something else to encourage more growth. The leaves that have appeared look healthy and green. Thanks