Some shrubs won't regrow a new flush of leaves if pruned after the first flush, so it's normal for them to not put out new growth in that case until the following spring. Fortunately, the close-up photo of the branch tips shows flower buds, so the plant did at least form those for next year's bloom period, which is good.

Mountain-laurel have a reputation for being picky about soil conditions; they need acidic (low pH) soil to thrive, but more importantly, they require good drainage. During drought, they do want to stay moist via supplemental irrigation, but accidental over-watering can kill roots, since they don't tolerate wet roots for very long. Similar to watering for other plants, feel the soil to help determine when watering is needed. Check about four inches down (compared to around six inches for plants not as shallow-rooted as Mountain-laurel), and if the soil becomes somewhat dry to the touch at that depth, watering is probably needed.

Yellowing and shedding leaves on evergreens can have several causes, so it can be hard to diagnose. Usually, it's either environmental stress (too wet or too dry) or part of the acclimation process for new plants, but the latter condition tends to only last a few weeks. Some of it is also normal, and might be exacerbated by stress earlier in the season. Evergreens do shed leaves seasonally, just to a lesser extent than for deciduous plants. In the case of azaleas and hollies, this shedding tends to occur in spring; for Mountain-laurel, pine, and some others, it occurs in autumn. What is shedding are the older leaves, which on a more established and denser plant, will be largely hidden from view. Since it's the oldest growth being shed, when pruning removes younger foliage, those older leaves will be more prominent when they yellow and fall. That appears to be what is happening here. Since Mountain-laurel are not highly drought-tolerant nor wet-soil tolerant, we don't think over- or under-watering is the sole cause for yellowing, though we can't rule out that it might be a minor factor in causing stress. Primarily, though, this looks like typical leaf shed that is common this time of year. As such, it should wrap-up in the coming weeks.

The leaf spotting is quite common on Mountain-laurel (and a wide variety of other plants, especially late in the season) and they can contract one or more fungal infections. Despite being an eyesore, generally, they are not too harmful to the plant's long-term health. If heavily-infected leaves cause some premature leaf shed during the growing season, then that could weaken a plant if it goes through multiple successive years of disease, but leaf spot infections tend to be very weather-dependent, and might not reach outbreak levels each year. This spring, when infection may have taken place (even if symptoms appeared later), the weather was wetter for a period of time. Wet leaf surfaces can be more vulnerable to infection by pathogen spores.

There is no need to remove infected leaves or attempt treatment, as fungicides will not be able to cure existing disease. While fungicides can sometimes be successful and preventing infection on new growth, their use may risk other organisms (like pollinators, if flowers are contaminated), and repeated applications would be necessary to maintain protection, so they are not practical to try in many circumstances and we generally don't recommend them.

If we have a dry winter (or periods of mild, dry weather during winter), check the shrub occasionally for watering needs. While it won't need watering nearly as often as it might in the growing season, it's still best to not let it (especially as a plant that hasn't been in the ground very long) get too dry during dormancy, so the foliage and flower buds don't dehydrate to the point of being damaged.

If deer visit the yard, keep an eye out for browsing damage, as they sometimes consume Mountain-laurel. In winter, deer will sometimes eat plants (especially evergreens) that they would otherwise pass by in favor of other options in summer.

Miri