Tulip trees are fall-foliage stars that get their name from the resemblance their flowers bear to the classic tulip flower. Native to North America and the state tree of Kentucky, Tennessee, and Indiana, Tulip trees can be most easily identified by the shape of their leaves, which boast a concave appearance at the ends where you would normally expect a point.
The flowers that give tulip trees their name are yellowish-green, with a touch of orange on the outside. The trees are best planted in early spring once the final frost has passed. They'll grow rapidly at first (more than 25 inches a year), then slow as they get older. In the spring, the tulip tree draws pollinators like hummingbirds and bees to the nectar in its flowers, while bobwhites, rabbits, squirrels, and other animals prefer to feed on the seed. The cone-like fruit the blooms leave behind also adds ornamental value.
|Botanical Name||Liriodendron tulipifera|
|Common Name||Tulip tree, tulip poplar, yellow poplar,|
|Plant Type||Deciduous tree|
|Mature Size||60–90 ft. tall, 30–50 ft. wide|
|Sun Exposure||Full sun|
|Soil Type||Rich, moist but well-drained|
|Soil pH||Neutral to acidic|
|Flower Color||Yellow-green, orange|
|Hardiness Zones||5–9 (USDA)|
|Native Area||North America|
Tulip Tree Care
Tulip trees have a storied history—in fact, you've probably seen them numerous times and not even recognized them, as they don't bloom until mature, at which point the flowers are so high up in the tall tree that they can barely be seen. A member of the Magnolia family, tulip trees are known for their massive height and sturdy wood. It used to be so well-loved by builders that it was used for railroad ties and fence posts and used by Native Americans and explorer Daniel Boone to make canoes—George Washington even planted several tulip trees at Mount Vernon.
Tulip trees can be purchased from a local nursery and planted any time between spring and early fall. They'll fare best in a sunny spot in moist, well-drained, compost-amended soil. Bark mulch or wood chips will protect their shallow roots and help to keep the soil moist—young trees need lots of water.
Size is a factor in deciding where to plant your tulip tree: They can reach 90 feet or more in height, with a canopy width just under one half their height at maturity. The branches begin rather far up the straight trunk and are often arranged symmetrically. However, the trade-off for their fast growth is relatively weak limbs, which can create a hazard in storms.
Tulip trees can be messy, as their flower petals will litter the area below just after blooming. The aphids that the tree attracts also make a mess with their honeydew secretion. They also are notorious for dropping sticky sap, so avoid planting a tulip tree near an area where cars will be parked—it's no fun trying to remove the sap from a car windshield.
Tulip trees prefer full sun or partial sun. Full shade can stunt the tree's growth and cause its leaves to turn brown. The sunnier the area where you plant your tulip tree, the better.
These trees prefer slightly acidic, well-drained, deep soil amended with plenty of compost. They can handle clay, sandy or loamy soils as long as the soil doesn't hold water too long. Don't plant a tulip tree in very dry soil, or soil that is too shallow.
As you get your tree started, water it regularly during dry, hot spells and keep an eye on its leaves. If you notice the leaves drop earlier than usual (early fall is typical), this could indicate the tree is not getting enough water.
Temperature and Humidity
Tulip trees like a temperate climate, which is why it can typically be found in the Eastern United States. While it prefers normal moisture levels, it can tolerate drought in locations with high humidity.
Granular, liquid, or stake type fertilizers are recommended for tulip trees. Newly planted trees respond well to fertilization, but older trees generally don't require fertilization.
Tulip Tree Varieties
Tulip trees are sometimes referred to as "tulip poplar" and "yellow poplar" trees, perhaps because their leaves shake in the breeze like those of poplars. However, they are not poplars at all and instead belong to the magnolia family, making them close relatives of magnolia trees. Family relations aside, Liriodendron and Magnolia are two different genera. Cultivars of tulip trees include:
- 'Arnold': This tree boasts a narrow, columnar crown and may flower at an early age.
- 'Fastigatum': The fastigatum tulip tree has a similar form to the 'Arnold,' but flowers at a later age.
- 'Florida Strain': Blunt-lobed leaves dot this varietal, which is also a fast grower and early bloomer.
- 'Leucanthum': The flowers on this varietal are white or nearly white.
Pruning Tulip Trees
Because tulip trees grow so fast, pruning is imperative in order to keep them shapely and controlled. Their large branches are not particularly sturdy and can pose a hazard to other trees nearby, not to mention people walking beneath them. Remove dead or weak growth in late winter and early spring, and do a thorough thinning every few years.
Propagating Tulip Trees
If you choose not to purchase your tulip tree from a nursery, you can instead propagate one using cuttings from a mother tree and following these steps:
Take cuttings in the fall, selecting branches that are at least 18 inches or longer. Cut the branch just outside of the swollen area where it attaches to the tree.
Place the cuttings in a bucket of water with rooting hormone added, following the directions on the label.
When you're ready to propagate, line a planter bucket with burlap and fill it with potting soil. Plunge the cut end of the branch approximately eight inches into the soil, then cover the cutting with plastic to hold in the humidity.
Place the bucket in a protected area that gets bright, indirect light. Check for root development a few weeks later. Your tulip tree should be ready for transplanting by spring.