The 2018 SMA Urban Tree of the Year is native to much of the Eastern United States and is cold hardy to Zone 4 and heat hardy to Zone 8b or 9. You may associate it with forests, but not so much with urban forests. Yet it definitely has its place in cities so long as its basic needs are met. It is the majestic tulip tree (Liriodendron tulipifera), a member of the magnolia family that reaches 60 to 90 feet in height and 30 to 50 feet in width. It’s named tulip tree because of the shape of its leaves, which emerge first, and its showy flowers, which follow and can be borne higher up in the canopy and somewhat hidden from view by the leaves.
In the plus column, tulip tree is fast-growing and beautiful, offers great wildlife value, tolerates acid soils and somewhat alkaline soils, tolerates soils that are occasionally wet, can grow in partial sun, and healthy specimens do not commonly suffer from diseases or insects. It is readily available in the trade, and there are more compact cultivars available, like ‘Emerald City’ from J. Frank Schmidt & Son Co.
In the minus column, it’s not tolerant of salt spray or soil salt, it’s sensitive to both drought and chronically poor soil drainage, it needs a large soil volume to meet its needs as a large shade tree, and it can be weak-wooded and drop a lot of branches, especially after ice storms. If used in urban environments, the planting sites need to be places like parks, parkways, rights-of-way, and extra wide medians with shared soil volume where the roots have enough soil volume to meet the tree’s needs, especially for water. The foliage of tulip trees in droughty conditions will yellow and the tree will become stressed.
Liriodendron is Greek for “lily tree” (leirion is Greek for “lily” and is Latinized to “lirio,” and dendron means “tree”) and tulipifera is Latin for “tulip-bearing.” So one could say it’s a “tulip-bearing lily tree,” although the reference to lilies is not well understood—the tree is in the magnolia, not lily, family.
Dublin, Ohio Assistant Forester Jocelyn Knerr nominated the tree. “I nominated the tulip tree primarily because it’s a native tree to Ohio, which makes it suited to our climate as well as being good for our wildlife. We started planting the tulip tree ten years ago in Dublin, mostly in rights-of-way. Their present diameter at breast height (DBH) is 10” and they are a good 35 to 40 feet tall. We just recently started planting the upright cultivar ‘Fastigiatum’ in parking lots; we will see how they do there. The tulip tree has become a resident favorite because of its attractive leaf shape and flowers as well as its bright yellow fall color.”
The SMA recognizes the underutilized, attractive, and useful tulip tree for its service to urban forests and encourages its use when matched appropriately to site and as part of a diverse urban tree inventory. You can see the full list of past Tree of the Year winners on the SMA website, www.urban-forestry.com.