Q.Globe Thistle
When does globe thistle begin to grow again? My thistle foliage turned yellow and limp. There is no sign of continued growth yet. What could cause this? Should I replant new globe thistle? The area is dry and receives a lot of mid to late afternoon sun.

Loss of plants can be due to many different reasons, not always can it be determined.
Watering issues, pests or fungus can present with yellowing leaves.
Here is a link to refresh you on the care requirements.
https://www.gardeningknowhow.com/ornamental/flowers/globe-thistle/growing-globe-thistle-plants.htm