Why is Tui Tomato Food not recommended for pots and containers?

Hi Diane, thanks for getting in touch. Tui Tomato Food is a blended fertiliser. Blended fertilisers are too concentrated for pots and containers (confined spaces) as there is no control mechanism - once applied it starts releasing the nutrients and can feed plants too quickly. For pots and containers use Tui Enrich Vege, Tomato & Herb controlled release fertiliser which is specially developed for growing plants in pots and containers. It releases only when the plant is actively growing and lasts for up to six months.