If you use coconut in your garden, make sure to keep the coconut moist at all times and add hydroponic fertilizer (preferably organic) if needed. If you use coconut in your garden, make sure to keep the coconut moist at all times and add hydroponic fertilizer (preferably organic) if needed. The biggest problem with coconut as a plant medium, above ground, or a pure hydroponic system is that it doesn’t contain any nutrients. If you decide to make the leap to hydroponic growing from the ground, using coconut is an easy way to make the transition from one to the other, as you already know how to feed your plants with nutrient-rich water.