There are many uses for baking powder in the garden. Take a tablespoon of baking powder and add to 3 litres of water. Use this as a fungicide, pesticide or herbicide in the garden. It also makes the soil alkaline. It helps to get the soil off your hands once you have finished gardening. Make a solution with of 3 teaspoons in 3 litres of water and use this water to clean bird baths, but don't forget to rinse them once you have scrubbed them clean. Pour some of this into ant holes and and wait a half an hour before pouring some vinegar into the same hole. If your compost heap is smelly, spray some of this onto the heap. If you are having a problem with cabbage worms in your vegetable patch, then mix some baking powder with some flour and sprinkle that on the ground around the plants. All worth a try!