Q.Yellowing leaves on hibiscus plant recently purchased.
Plant was made into a topiary. Just repotted from pot purchased in. Soil seems rich and damp but plant is a bit puny.
Certified GKH Gardening Expert
Make sure you choose a pot just 1 or 2 sizes larger than the existing pot. Use a good quality potting soil.
These articles will help you.
https://www.gardeningknowhow.com/ornamental/flowers/hibiscus/answers-to-what-causes-hibiscus-leaves-turning-yellow.htm
https://www.gardeningknowhow.com/ornamental/flowers/hibiscus/how-to-care-for-hibiscus-plants.htm
https://www.gardeningknowhow.com/ornamental/flowers/hibiscus/hibiscus-fertilizing.htm