The tulip tree (known as tuliptree, American tulip tree, tulip poplar and yellow poplar) can adapt to most habitats except for desert climates. It is native to the eastern United States, and is known for its late spring, 2-inch, yellow tulip-like flowers. In landscape design, it is used mainly as a large shade tree, whose foliage turns bright yellow in the fall. Insects that can cause a problem are the tulip tree aphid and the tulip tree scale.
This columnar deciduous tree can reach a height of from 60 to 80 feet, and a spread of from 30 to 50 feet. As the tree matures, the trunk becomes large with furrowed bark. Its growth rate is moderate. The tulip tree requires full sun, and tolerates clay, loam, sand or acidic soils (soil must be well-drained.) This large tree does not do well in drought conditions--it may shed interior leaves prematurely. It is hardy in zones 5 through 9A.
Tulip Tree Aphids
Aphids are a common pest, which attack a vast variety of plants and trees--there are more than 350 species of aphids. The tulip tree aphid is green and it can be found feeding on the underside of the tulip tree leaves. This particular species of aphid can grow in numbers quickly.
What Aphids Do
When you have an aphid infestation you will notice leaf distortion on new growth, honeydew deposits, and sooty mold. These sap-sucking insects can cause the leaves to die or curl up/wilt. Aphids excrete honeydew--honeydew is waste material. Sometimes the honeydew becomes more of a problem than the insect. Honeydew is a sticky substance. It can cover not only the leaves and branches of the tree but walkways and patios. The honeydew then attracts various other insects: ants, yellow jacket wasps, flies and bees. Sooty mold also forms and grows on the honeydew, which further affects the appearance of the tree.
Controlling Tulip Tree Aphids
The natural enemies of the tulip tree aphid are parasitic wasps, lady beetles, flower fly larvae and lacewing larvae. Frequently, the aphid’s natural enemies take care of the infestation. In severe cases applying an insecticide or insecticidal soap can control the tulip tree aphid.
Tulip Tree Scale
Tulip tree scales are found on the branches of the tree. This soft scale will not kill the tree--the tree will become less vigorous. Female scales are approximately 1/3-inch in size, hemispherical in shape, and brown in color. Male tulip scales are smaller, flat, and gray in color. Infestations begin in September. According to the Connecticut Agricultural Station, “ They are less than one-fourth grown when winter arrives. Spraying with horticultural oil before growth starts in the spring will control the scales.” The best defense against an infestation of tulip tree scale is to maintain a healthy tree, as these scales usually attack a weakened or stressed tree.
- United States Department of Agriculture Forest Service: Liriodendron tulipifera ulip tree
- Purdue University Plant & Pest Diagnostic Laboratory: Tulip tree scale
- The Connecticut Agricultural Experiment Station: Tulip tree (Liriodendron)
- University of California: Pests in gardens and landscapes
- University of Kentucky: College of Agriculture: Tulip tree scale