Answer: In my experience, these shrubs can take a year or so to settle in and as a rule do not grow terribly fast so the growth rate you are seeing could be close to normal for the first year. However the leaf loss bothers me. Usually this type of foliage problem is caused by over or underwatering. You need to water them carefully so that the soil is moist but not soggy; the rule of thumb is an inch or two of water a week from either the sky or the hose. It is best applied in a slow deep soaking rather than daily light sprinklings and you might want to dig down and see how effective your watering is so you know how much to apply at a time. A few inches of organic mulch over the root zone (but not touching the stem) will help keep the moisture in and the soil cool.
Although it is unusual, you might also take a very close look at them and make sure there is no insect problem; look carefully along the undersides of the leaves and along the stems and branches.
Good luck with your burning bushes!
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