Strelitzia Problems

Root Rot

• Strelitzia occasionally suffers from root rot when planted in moist soils or exposed to high humidity. Armillaria fungal root rot affects the plant's ability to transport water and nutrients. The first symptoms are usually noticed aboveground, and include undersized, or off-colored leaves, mushrooms around the base of the plant, and premature leaf drop. Both the fungi Rhizoctonia and Pythium cause soft, mushy roots which can no longer support aboveground foliage, which turns yellow and dies.

Bacterial Diseases

• Some bacterial diseases strike Strelitzia. Bacterial wilt is caused by Pseudomonas, a bacteria that initially produces small, watersoaked areas on leaves. Later, the necrosis spreads and affects the entire plant, causing it to eventually die. The bacteria enters through an existing wound. Bacterial leaf spot is caused by the bacteria Xanthonomas, and produces yellow to rust-colored, watersoaked spots on leaves, which expand to form large blighted areas. Plants eventually die.

Sucking Insects

• Sucking insects on Strelitzia are often difficult to locate because they hide under leaves or in the crotches of leaves or stems. Scale insects resemble small helmets under which the insects are protected. They are found under leaves and along stems. Mealybugs look like cottony masses and are found under leaves and along stems. Aphids are normally transparent green or brownish fleshy insects found on leaves. All these insects pierce plant parts and suck vital juices. In small numbers, leaves may turn yellow and die. In large numbers, plant growth is slowed and plants may eventually die.

Flying Insects

• Flying insects on Strelitzia are often easier to see than sucking insects, since they often fly about when the plant is disturbed. Whitefly is usually a greenhouse problem, but can be found in landscapes as well. As the name suggests, these tiny flies are pure white. Glassy winged sharpshooters are brownish oblong insects with wings that resemble paned glass. Both insects suck sap from the leaves or fleshy stems, and can cause yellowing and premature drop of leaves. Where there are large insect populations, plants may die.

Other Problems

• Other problems may affect Strelitzia. Crown borers bore holes into the crown of the plant. Eggs are laid in the hole, and when larvae emerge they eat the plant flesh. The foliage, as a result, turns yellow, then wilts and dies. Botrytis is a fungus that causes flowers to become discolored and infected leaves may discolor or drop. Sooty mold is a secondary fungal infection which causes a black coating on leaves, but it grows in honeydew left behind by leaf-sucking insects, not the leaf itself.