In a medium saucepan, combine the rhubarb, sugar, water, and lemon juice. Stir gently to combine.

Bring the mixture to a boil over medium-high heat, stirring occasionally to prevent sticking.

Once boiling, reduce the heat to medium-low and simmer for 20-25 minutes, or until the rhubarb is tender and the syrup has thickened slightly. Stir occasionally to prevent burning. The rhubarb should be translucent and easily pierced with a fork.

Remove the saucepan from the heat and let the candied rhubarb cool completely. The syrup will thicken further as it cools.

Once cooled, you can store the candied rhubarb in an airtight container in the refrigerator for up to a week. The candied rhubarb can also be frozen for longer storage.

For a more intense flavor, consider adding a pinch of vanilla extract or a cinnamon stick during the simmering process. Remove the cinnamon stick before cooling.