Yellow Leaves on a Hawaiian Umbrella Tree

Watering

• The Hawaiian umbrella features an aerial root system, a style that grows above the ground. This style of root makes it easier to grow these plants in rocky areas, but also means they will have very specific watering requirements and improper watering is a common cause for leaf yellowing. The amount and frequency of watering will depend greatly on the amount of sun and heat the plant is exposed to. The sunnier or hotter a climate, the more water is necessary. Keep the soil damp, but don’t allow water to stand at the base of the plant. A good rule of thumb is to water every two to three days as needed and don’t allow the soil to dry out. Water only when the plant requires it, not on a specific schedule.

Humidity

• Humidity is a key factor in keeping leaves of the Hawaiian umbrella tree green and healthy. Indoor plants, particularly those located in areas that are dry will require misting, a process that will increase dampness in the air. Misting by hand requires the use of a spray bottle and a frequency or amount determined by local conditions and needs of the plant. A humidity tray is filled with water and placed near the plant. The water evaporates and keeps the leaves moist. Never place an umbrella tree near a vent or in a drafty area.

Fertilizing and Nutrient Deficiency

• Nutrient deficiency, particularly when iron or nitrogen are in short supply, is among the most common causes of yellow leaves on Hawaiian umbrella plants. Fertilize on a bi-weekly schedule with a full strength, water soluble fertilizer. It is essential that this process be started when the plants start actively growing and continues as long as new growth is present. Both iron and nitrogen are key to producing chlorophyll within the leaves. Without these elements, leaves will turn yellow, brown, then drop completely.

Pests and Illness

• Most plants, indoor or outdoor, will experience pest problems or illness at some point. These are the two most common causes of health decline and foliage problems in plants. When grown outdoors, pests are not usually a problem, but indoor grown umbrellas often fall victim to scale, spider mites and mealy bugs. When left untreated and present in large numbers, each of these will potentially cause foliage to become discolored. Preventing these problems is key to maintaining overall health and starts with removing any fallen or dead debris from the base of the plant. Spider mites are part of the arachnid family and are almost invisible to the naked eye. They come in a range of colors, including red, brown and green, and are difficult to get rid of on indoor growing plants. Any infected areas must be removed, bagged and discarded and the plant wiped or sprayed down once per week until the pests are gone. Standard oils and soaps are ineffective. Scale is another pest that is more harmful to indoor umbrellas than their outdoor counterparts. These are also noted for causing leaf damage and yellowing, but are treated with horticultural oils or soaps applied during the dormant stage of life.