Answer: I think the leaves are behaving normally. They tend to be a lighter green after they've unfurled. I found a photo on the web: http://www.uafortsmith.edu/Arboretum/HarryLaudersWalkingStic...
When you pull up the page you'll see a larger photo of the entire shrub and a smaller photo of the leaves. Click on the smaller photo and a new window will come up with a larger version of the photo. If your plant looks like this, it's perfectly fine. If the foliage is a lighter green than in the photo you might try feeding it. Use a water soluble fertilizer such as Miracle Gro and dilute it to half-strength. Use this in place of one watering once a month and you should see a difference in the foliar color.
It sounds as though you've done everything right in terms of planting, watering and sun exposure. It's possible your plant didn't produce catkins last winter because it was too immature. I'll bet it will produce some this year.
Best wishes with your contorted filbert!
Q&A Library Searching Tips