To use bean cake as fertilizer, it is necessary to ferment the bean cake separately and fully in advance before it can be mixed with flower soil to grow flowers. Because bean cake fermentation will release a lot of heat, which will burn the roots of flowers and lead to the death of flowers. The correct fermentation method is to mix the bean cake with the same amount of garden soil and water, and it is advisable not to drop water by hand, then put it into a plastic bag, seal it and naturally ferment it in the shade. Summer may take more than a month to completely decompose. When it is used in the future, it should be mixed with flower soil as fertilizer as appropriate. If you put it in the open air without sealing, it will definitely attract flies to lay eggs. Dig out the bean cake quickly, or the flowers will die.