The Liriodendron, or tulip poplar, is a genus of two species of characteristically large deciduous trees in the Magnolia family (Magnoliaceae). The tulip poplar is sometimes know as a “Tulip Tree” or “Yellow Poplar”, and the wood simply referred to as “Poplar,” although it is not closely related to the true poplars of the genus Populus.
The tulip poplar species is a major honey plant in the Eastern United States, yielding a dark reddish, fairly strong honey which gets mixed reviews as a table honey but is favored by bakers. The tulip poplar is also the state tree of Indiana, Kentucky, and Tennessee.
Seasonal information: April marks the start of the flowering period in the Southern USA. Tulip poplar trees at the northern limit of cultivation begin to flower in June. The flowers are pale green or yellow (rarely white), with an orange band on the tepals; they yield large quantities of nectar.
Location: The tulip poplar does best when growing in moist soil that drains well. Deep and nutrient rich soil is ideal for most trees and this species is no exception; however, the tulip poplar can adjust to ordinary drier soils with a slightly alkaline pH level. Tulip poplars require partial sun to full sun to thrive and will not do well in the shade. Someone who purchases a tulip poplar as a landscaping tree should make every effort to avoid planting it in hot dry areas of their property. Conversely, the tree will not prosper if the soil is constantly saturated with water.
Planting instructions: When planting, prevent your roots from drying. In many cases, the damage that occurs to roots happens when the trees are planted. Plant your tree with damp roots and minimize root pruning. The more healthy, active roots a seedling has, the better it will survive and grow. Therefore, dig a large hole to make plenty of room for the roots. It is better to dig a big hole to accommodate all the roots than to cut roots for a smaller hole. The hole should be twice the width and height of your tree’s root system. Spread out the roots evenly in the hole and surround them with dirt so that there are no air pockets. If pockets of air are present, the roots of your trees will dry out. Plant your tree so that the roots of the tree are covered and the stem is above ground level. Be sure to cover up to one inch of the stem of your tree. When watering the soil will compact and sink. Pack the loose soil firmly around the roots.
Watering: When young, make sure your tulip poplar tree gets water during extended dry spells, particularly in the summer months. Drooping branches are a sign of both over- or under-watering, so take great care of your tree.
Fertilization: Tulip poplar trees love fertilizer. Use only slow-release fertilizer tablets for the first growing season. Do not use stronger fertilizers until your tree becomes more established. You can use Miracle Grow, a 10-10-10 or 20-20-20 fertilizer. Fertilize twice a month when the tree is coming out of dormancy, then once a month during the summer. Stop fertilizing before the tree goes back into dormancy.
Weed Control: Keep weeds and grass two to three feet away from the tree in the first year. The grass will compete with your tree for nutrients in the soil. Pull the weeds initially, and then you can use a growing mat or mulch. Do not spray RoundUp on a young tree, and be careful that wind does not blow chemical drift on the tree.
Pests and Disease: The tulip poplar’s most common enemies are the fusarium and nectria canker, and the yellow-polar weevil.
Pruning: Cut off any damaged branches. To check whether a tree branch is healthy and living, scrape the wood with a knife. Greenish white underneath the bark indicates a living branch. Brown or black means the branch is dead. Make a 45-degree downward angled cut to a healthy outward-growing branch. Cut off any branches that are growing outside of the designated planting area. To cut off a branch, make a cut right next to the branch collar. The branch collar is the swelling that attaches the branch to the trunk. Remove any competing leaders. Tulip trees generally will grow with one strong central leader (vertical growing shoot); however, if there are other competing leaders cut them off near the trunk. Examine the tree for fungal infections. Fungal infections such as tree cankers caused by the fungus myxosporium create swellings on branches. To remove, dip your pruning tool in a mixture of 70 percent denatured alcohol and 30 percent water in between cuts to avoid spreading the disease.
Pollination: The poplar flowers in the early spring. They are found at the ends of the leafy twigs high up in the tree canopy (often you have to use binoculars to see them!). These beautiful flowers are pollinated especially by honey]]bees. The fruit that forms from these pollinated flowers is a cone-shaped mass of many, one- to one-and-a-half-inch, narrow-winged samara (seeds plus “wings” to aid dispersal). These samara begin to be shed in the autumn and will continue to fall to the forest floor through the winter.