Introduction
'Glenleven' littleleaf linden grows in a cone shape about 50 to 70 feet tall and can spread 40 to 50 feet in most landscapes. This tree has a faster growth rate than other littleleaf lindens with a more open, canopy forming a moderately dense pyramidal to oval crown which casts moderate shade. Littleleaf linden is a prolific bloomer, the small fragrant flowers appearing in late June and into July. Many bees are attracted to the flowers, and the dried flowers persist on the tree for some time. Japanese beetles often skeletonize Linden foliage, in certain areas in its range. Defoliation can be nearly total and mature trees can be killed by repeated severe infestations. Planting linden in areas with severe infestations of this pest may not be wise. However, at least one reference reports that defoliation by Japanese beetles is common but control is seldom needed.
General Information
Scientific name: Tilia cordata
Pronunciation: TILL-ee-uh kor-DAY-tuh
Common name(s): 'Glenleven' littleleaf linden
Family: Tiliaceae
USDA hardiness zones: 4A through 7A (Fig. 2)
Origin: not native to North America
Invasive potential: little invasive potential
Uses: hedge; urban tolerant; container or planter; street without sidewalk; screen; shade; specimen; parking lot island > 200 sq ft; sidewalk cutout (tree pit); tree lawn 4-6 feet wide; tree lawn > 6 ft wide; highway median
Availability: somewhat available, may have to go out of the region to find the tree
Description
Height: 50 to 70 feet
Spread: 40 to 50 feet
Crown uniformity: symmetrical
Crown shape: pyramidal, oval
Crown density: moderate
Growth rate: fast
Texture: medium
Foliage
Leaf arrangement: alternate (Fig. 3)
Leaf type: simple
Leaf margin: serrate
Leaf shape: orbiculate, cordate
Leaf venation: pinnate
Leaf type and persistence: deciduous
Leaf blade length: 2 to 4 inches
Leaf color: green
Fall color: yellow
Fall characteristic: not showy
Flower
Flower color: yellow
Flower characteristics: showy
Fruit
Fruit shape: round
Fruit length: less than .5 inch
Fruit covering: dry or hard
Fruit color: brown, tan
Fruit characteristics: does not attract wildlife; showy; fruit/leaves not a litter problem
Trunk and Branches
Trunk/bark/branches: branches droop; not showy; typically one trunk; thorns
Pruning requirement: little required
Breakage: resistant
Current year twig color: brown, green
Current year twig thickness: thin
Wood specific gravity: unknown
Culture
Light requirement: full sun, partial sun, or partial shade
Soil tolerances: sand; loam; clay; acidic; alkaline; well-drained; occasionally wet
Drought tolerance: moderate
Aerosol salt tolerance: none
Other
Roots: not a problem
Winter interest: no
Outstanding tree: yes
Ozone sensitivity: unknown
Verticillium wilt susceptibility: susceptible
Pest resistance: resistant to pests/diseases
Use and Management
Small lateral branches arise from the single, straight trunk in an upswept curve but quickly bend gracefully toward the ground. Middle aged and old trees somewhat resemble the pin oak with its single trunk and drooping lower branches. Be sure to purchase and train Linden to one central trunk with well-spaced, small-diameter lateral branches. The cultivars 'Greenspire' and 'June Bride' have also been developed for their very straight trunk. Linden may sprout from the base and these will have to be removed from time to time.
The tree grows in sun or partial shade, will tolerate alkaline soil if it is moist, and it transplants well. It is not particularly tolerant of drought, scorching at the leaf margins in summer drought. But this apparently does little long-term harm. It is more tolerant of heat and compact soil than American basswood. Many communities plant linden along the streets due to its rapid growth rate and dense, symmetrical crown but littleleaf Linden is sensitive to road salt.
The wood of Linden is clear white, soft and often used for drawer sides in inexpensive furniture. Though not as soft as balsa wood, it sands poorly and is difficult to finish.
There are several cultivars: 'Chancellor'—upright when young but becoming pyramidal, fast growth, with a straight, single trunk: 'Greenspire'—straight trunk and radially produced branches-may be the least-maintenance cultivar; 'June Bride'—pyramidal, glossy leaves, profuse flowering; 'Pyramidalis'—widely pyramidal; 'Rancho'—narrow, upright growth habit, very small, fine textured leaf - a beautiful tree; 'Sterling' is supposed to resist Japanese beetles.
Pests
Despite susceptibility to various insects and diseases, control is usually not needed except for Japanese beetle.
Japanese beetles often skeletonize linden foliage, in certain areas in the northern part of its range. Defoliation can be nearly total and mature trees can be killed by severe infestations. Planting linden in areas with severe infestations of this pest is not recommended.
Aphids can be a problem on linden causing the production of honeydew. This is more of a nuisance than a life threatening problem.
Several caterpillars feed on linden. Have the insect identified then apply the appropriate control, if needed. Bacillus thuringiensis will not be effective against sawfly larvae. Fall webworm nests can be pruned out when still small.
Lace bugs cause discoloration of the leaves. The insects are found on the undersides of the leaves and can cause some early defoliation but are otherwise harmless.
Spider mites cause leaves to become stippled and yellowed. The mites are usually not discovered until there is a significant infestation.
Diseases
No diseases are usually serious.
Anthracnose causes elongated light brown areas next to the veins. The spots may be anywhere on the leaf but are most often near the tip. The spots are bordered by a distinct black band. Severe infections defoliate the tree. The disease does not require chemical controls every year but repeated severe infections may justify spraying.
Leaf blight causes leaves to brown and fall. The early symptoms are round, brown spots with dark borders. The spots become numerous leading to leaf browning and drop.
Several fungi cause cankers and dieback on branches and trunks. Remove infected branches as they occur and avoid wounding the tree. Fertilizing infected trees may help.
Powdery mildew forms a white coating on the leaves but is usually not serious and does not require treatment.
Verticillium wilt causes dieback and death of individual branches or the entire tree. Keep trees healthy with a regular fertilizer program to help prevent the disease.