4 Pieces Assorted 14.5" Glass Plant Watering Bulbs - Blue, Green, Multi, Red. What a wonderful gift for the plant lover. These beautifully hand blown glass watering bulbs function as a supplemental water device for your potted plants. Just fill the bulb through the stem with water. Then make a hole in your potted plant with a stick (do not use plant bulb) and insert stem gently into the hole. Now sit back and watch as nature takes it course. The plant bulb will release water to the roots as the plant needs it, so you can easily go away for a weekend and not worry about watering your plants. For larger potted plants, we suggest using more than one plant bulb. Each plant bulb comes in a gift box ready to be given as a gift.