Tuliptrees (Liriodendron tulipifera), also known as tulip or yellow poplars, occur throughout the eastern United States, dominating eastern forests as the tallest trees. Tuliptrees produce abundant, large orange and green flowers in the spring, revealing their close relationship to magnolia trees. Understanding the root system of the tuliptree and its function helps you to be able to better care for this magnificent forest tree.
The tuliptree reaches heights up to 100 feet, according to the University of Florida IFAS Extension, and it is no surprise that it has a root system to match. The extension describes the tree's root system as needing lots of room to grow, a factor to keep in mind when considering tuliptree plantings.
A study published in the May 2002 volume of Ecological Monographs looked at the amount of root branching on several tree species, including the tuliptree. Large amounts of root branching improve the tree's ability to absorb water and nutrients from the soil. The study found that tuliptree was the only species where fewer than 75 percent of the roots were lateral, branching roots. Ohio State University adds that tuliptree tends to have fleshy, coarse roots.
Tree roots, including those of the tuliptree, provide the tree with its water and nutrients. The outer layer of root cells absorbs water and, with it, dissolved minerals. The water and minerals pass into vascular tissue called xylem, which is pulled to the top of the tree when water evaporates from the leaves. Trees benefit from having maximum root surface area in contact with the soil for absorbing water and nutrients. Tiny fibers called root hairs and beneficial fungi called mycorrhizae increase the tree's ability to absorb water.
Tree roots can pose problems to property owners if surface roots lift driveways and sidewalks. However, according to the University of Florida IFAS Extension, the roots of the tuliptree do not normally cause problems. Because tuliptree roots do not develop extensive lateral branches, they are more susceptible to drought and prefer moist locations. However, the Ohio State University reports that mature trees do adapt to drier conditions, although they may lose their leaves during droughts.
A serious root disease known as Verticillium wilt can affect tuliptrees. Fungi invade the tree's root system, plugging up the vascular tissue and preventing water from reaching the top of the tree. Trees wilt and, eventually, die. There is no cure for the disease. Avoid wounding tree roots or trunks with lawn equipment, as this provides easy entry for the pathogen.