Hi, I maintain the garden at a local cafe, and the redbud has steadily been declining over the past 2 seasons. The tree is about 7 years old. I suspect it may have been overwatering, as there were a number of irrigation lines in the bed from a previous planting layout, so the tree was getting watered every 2-3 days for about 10 to 15 minutes before we discovered the issue. However, the patio area was also redone with stonework 3 years ago, so I didn't know if the roots could have possibly been damaged during that work and if that is the culprit. If it does look like overwatering, will the tree recover or should I replace it? I removed the excess driplines this year, but the tree has not improved very much. Thank you!
It is hard to say exactly what is stressing your redbud and it may be a combination of factors.
We can't say the watering is implicated without knowing the rate of flow, but in general long, slow drinks spaced out are better than short intervals for a short time.
Redbuds don't like wet feet, but they do need regular and consistent moisture. How is the drainage? Decent soil?
More on the tree in general here: https://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?kempercode=h550
The installation of the sidewalk could absolutely disturb or cut needed roots or compact soil which you would expect to show up as wilting or dieback in the leafy canopy.
How deep is the soil there and what is underneath?
Too shallow a hole and planting/mulching too deeply can also lead to decline and slow death over time.
More possible cultural/environmental issues can be found here: https://extension.umd.edu/hgic/topics/cultural-and-environmental-0
We would let it go for a while longer to see if it improves. Keep it watered.
Here is our page that helps people decide when it may be time to remove a tree: