Why is my sweet potato not producing tubers?

Sweet potato tuber failure usually comes down to nitrogen excess — overfed plants produce beautiful vines with no underground storage. Use low-nitrogen, phosphorus-potassium-rich soil. Container must be at least 12 inches deep and 20+ litres. Sweet potato also needs a long growing season (90–120 days) — harvesting before leaves yellow gives small tubers. Varieties matter: Sree Bhadra and Kiran produce well in Indian container conditions.