Hi, 

Thank you for using Ask Extension.

Based on the symptoms you are describing across multiple plants (tulips, roses, groundcover, and a small tree), it is unlikely that a single infectious disease, such as tulip blight, is the primary cause. Instead, the pattern you are seeing is much more consistent with environmental stress due to the drought we have been experiencing throughout this past winter and spring. 

The recommendations going forward:

Begin deep, consistent watering as allowed by the current water restrictions, especially for the tree and roses

Continue to monitor new growth, plants should recover from the stress as moisture improves

Prune out the dead wood on the tree and roses once you see signs of recovery

Avoid fertilizers until the plants are showing signs of recovery

If the tulips fail again next year replanting may be necessary

Happy Gardening,

Elizabeth, Jeffco Master Gardener