There are a couple likely causes behind the discoloration. The reddening is normal and, while it can also be a sign of stress, it can be typical of young foliage, since the red pigment is a sort of "sunscreen" for the leaf as it matures. Sometimes these pigments are also a reaction to wounding, either from physical damage or infection. We don't see any indications of leaf spot or powdery mildew infections in the photos. The yellowing of foliage while the veins remain greener is called chlorosis. It is a type of nutrient deficiency, but it doesn't necessarily mean the soil itself is deficient. Instead, it could indicate that the roots are not functioning as well as they could be, or that the soil is not as acidic (having a low pH) as the plant needs it to be in order to access nutrients that are already plentiful in the soil. The only way to know for certain if the soil conditions are contributing to leaf yellowing is to have a laboratory soil test performed. (Home soil testing kits/probes are generally less accurate and less detailed, and sometimes the results are harder to interpret.) We can help to interpret the lab results if desired.

Dogwoods require an acidic soil to thrive, so if your soil's pH is too high, it could be lowered using garden sulfur. (Use the application rate recommended by the lab, if given, or the rate recommended on a sulfur package, which should indicate how much to apply to bring a given starting pH level down to a certain target pH level.) While chlorotic leaves don't always green-up after a nutrient deficiency is corrected, new growth produced after the adjustment should at least be a more normal, even green color. We don't recommend fertilizing the tree without learning what the pH level and current nutrient levels are, since it might not be necessary to supplement any nutrients.

Roots that are struggling to function well can be a cause of chlorosis and overall plant stress. Dogwood trees prefer evenly-moist soil that does not stay too wet, nor which is prone to drought (if it can't be watered as needed). This can be monitored by feeling the soil about six inches deep next to the root zone and watering thoroughly only once the soil becomes somewhat dry to the touch at that depth. How often that will happen depends greatly on weather and soil type/drainage, but as a very rough guideline, once we move into summer, in a stretch of hot dry weather, a soaking once a week might be on-target with what the plant needs. It's hard to say if this tree might have been kept too wet or got too dry at some point (perhaps neither), since symptoms can overlap between these and other sources of stress. Poor root development by the time the plant was sold is another possibility, though not one we'd be able to verify.

Some "transplant shock" stress is to be expected for most plants moved or planted in the weeks following installation, though the severity of that can depend on many factors, including weather trends. The recent period of overcast, somewhat-wet weather has been good overall for reducing shock to many plants going into the ground for the first time. There does appear to be a bit of scorch on some leaves, where the tips or margins are browning, which can occur when roots are too dry or even too wet. (Roots that are too wet for too long can't absorb what the plant needs, despite the abundant moisture, because the excess water displaces needed air in the soil pore spaces, so the roots "suffocate" and don't function well. Plants may recover in that situation if only a few roots are stressed or killed, but advanced root loss is usually fatal. There is no intervention possible once the plant reaches a tipping-point of too much root loss.) We don't think your tree has succumbed to root rot at the moment, but it's something to keep in mind as you monitor its watering needs or if it displays wilting symptoms while the soil is still moist.

We can't tell for certain from the photos, but it looks like the dogwood might be planted in full sun (6-8 or more hours of summer sun). If so, be aware that this can cause them more stress overall, at least during hot weather, as they are mostly adapted to woods-edge and open woodland conditions, where they receive a bit of shade from taller trees for part of the day. We have seen many mature dogwoods grown in full sun, so it's not a given that they will struggle, but just be aware that they are less adapted to those conditions and might need more long-term monitoring for watering needs than trees growing in semi-shade.

Planting depth can affect root health, both soon after installation and years after the fact. Make sure the tree's root flare is situated right at the soil surface and not buried a few inches below-grade. Similarly, make sure mulch is not piled against the bark, and that the layer is flat and only about 2-3 inches thick overall. If any herbicides are used on the lawn around it, making the mulch ring as wide as possible will not only reduce root competition between the tree and the grass, but also reduce the risk of root zone contamination from certain herbicides that might cause damage. Montgomery County does restrict lawn herbicide use, so the ingredients of most concern you probably aren't using, but we mention it just in case since we have seen dogwoods and other sensitive trees damaged by lawn herbicide applications that overlap their root zones.

For now, just keep an eye on the tree, make sure any stakes that came with the plant to sturdy its trunk for shipping are removed, and monitor the soil moisture level before assuming the tree needs water. New leaf/branch growth may be limited its first year or two since it will be directing lots of energy into root establishment. If any symptoms worsen or change, feel free to send us additional photos for evaluation. Even if no treatment is possible for other issues, we can try to determine what happened so it can be avoided in the future.

Miri