Troubleshooting
Rounded Sweetgum problems — and how to fix them
Rounded Sweetgum (Liquidambar styraciflua 'Rotundiloba') is generally forgiving once you match its basics, but a few issues come up again and again. Here is what each one looks like, why it happens, and the fix.
Chlorosis (yellowing leaves)
Caused by high soil pH preventing iron uptake. Test soil pH and amend with sulphur or acidifying fertiliser if above 6.5. Chelated iron foliar spray can provide quick relief.
Leaf spot fungi (Cercospora, Actinopelte)
Brown or purple spots with yellow halos appear in wet seasons. Usually cosmetic; rake and dispose of fallen leaves, improve air circulation, and avoid overhead watering.
Root girdling / poor transplant establishment
Sweetgums have a deep taproot and dislike transplanting. Plant balled-and-burlapped stock in spring, water diligently for 2–3 seasons, and avoid planting in confined spaces where circling roots can develop.
Prevent rounded sweetgum problems before they start
Most rounded sweetgum issues are care-mismatch, not bad luck. Dial in the basics:
Rounded Sweetgum problems — FAQ
Why is my rounded sweetgum chlorosis (yellowing leaves)?
Caused by high soil pH preventing iron uptake. Test soil pH and amend with sulphur or acidifying fertiliser if above 6.5. Chelated iron foliar spray can provide quick relief.
Why is my rounded sweetgum leaf spot fungi (cercospora, actinopelte)?
Brown or purple spots with yellow halos appear in wet seasons. Usually cosmetic; rake and dispose of fallen leaves, improve air circulation, and avoid overhead watering.
Why is my rounded sweetgum root girdling / poor transplant establishment?
Sweetgums have a deep taproot and dislike transplanting. Plant balled-and-burlapped stock in spring, water diligently for 2–3 seasons, and avoid planting in confined spaces where circling roots can develop.