Provided is a device for displaying the timing for water supply for soil which has a simple structure and notifies a user of the appropriate timing for water supply for soil based on an amount of moisture in soil. The device for displaying the timing for water supply for soil includes: a post member formed in the shape of a cylinder a head member which is connected to an upper end portion of the post member, and is formed in the shape of a calyx a water expansion member which has a lower end portion fixated to a lower end portion of the post member, has an upper end portion fixated to an upper end portion of the head member, and is made of a material expanding if the material absorbs water and contracting if the material dries a fixation member which is installed on the upper end portion of the head member and allows an upper end portion of the water expansion member to be fixated thereto a support member which is installed to be able to vertically move in the head member, allows a lower end portion of the fixation member to be inserted and joined to the inside thereof, and has a joining groove formed on an upper end portion thereof an elastic member which is installed between the support member and the head member, and is installed to be in a state of applying upward force on the support member and display members in the shapes of petals, which have lower end portions installed on the head member to rotate, have tips of the lower end portions inserted into the joining groove of the support member, and repeat gathering and spreading motions while the display members rotate as the support member vertically moves.COPYRIGHT KIPO 2016간단한 구조로 토양 내부의 수분 양에 따라 물주는 시기를 적절하게 안내하는 것이 가능하도록, 원통형상으로 형성되는 기둥부재와, 기둥부재의 상단에 연결되고 꽃받침형상으로 형성되는 머리부재와, 하단부는 기둥부재의 하단에 고정되고 상단부는 머리부재의 상단에 고정되고 수분을 흡수하면 팽창하고 건조되면 수축하는 재질로 형성되는 수팽창부재와, 머리부재의 상단에 설치되고 수팽창부재의 상단부가 고정되는 고정부재와, 머리부재의 내부에 상하로 이동가능하게 설치되고 고정부재의 하단이 내부에 삽입 결합되고 상단부에는 결합홈이 형성되는 지지부재와, 지지부재와 머리부재 사이에 설치되고 지지부재에 위쪽으로 힘을 가하는 상태로 설치되
