Description of Water Care for Hibiscus Roots

How Much Water

• Hibiscus plants need 1 inch of water a week, according to the National Gardening Association. This water comes from the rain, irrigation system or the gardener. To find out how much rain or irrigation water your plant has received, place tuna cans next to your hibiscus plant. Measure the amount of water in the can and supplement any water. Gardeners can also check the hibiscus plant's soil before watering by pressing their fingers into the first 3 inches of top soil. These tropical plants need moist, but not saturated, soil.

Watering Plants in the Ground

• Hibiscus plants need to be watered so that the soil is moist 12 to 18 inches deep in the ground, according to the University of Florida. To apply this moisture, use a drip irrigation system or slowly apply water. Apply the water on the hibiscus dripline. The dripline is that area that is directly underneath the tips of the foliage. Dig an 18-inch hole after applying water to make sure that the soil is moist. Note how long the irrigation system was on to achieve moist soil at that depth.

Watering Container-grown Plants

• Container-grown hibiscus plants must be watered by lifting them off their saucer. Pour water around the diameter of the container until water drains from draining holes. Place the container on a saucer that has a 1-inch layer of pea gravel. The pea gravel aids in drainage and increases the humidity around the plant. Also, do not let the water that collects in the saucer touch the bottom of the container. Fungal diseases are more prevalent when the bottom of the soil in the container is kept moist.

Other Considerations

• Overwatered hibiscus plants are at risk for contracting a disease called root rot. Root rot is caused by either fungal spores or bacteria. Hibiscus plants kept in a soil medium that drains poorly or have been overwatered are at greatest risk for the disease. Gardeners that have infected hibiscus plants may notice an overall health decline for the plant. To check to see if your hibiscus has root rot, lift the plant out of the soil. Black or brown mushy roots indicate the hibiscus is infected with root rot.