Little-leaf linden (Tilia cordata) trees can be charming additions to your garden. As the name suggests, these trees have smaller leaves than others in their genus, also making them ideal to be trained for bonsais. Though purely ornamental, they are also known as “small-leaved lime trees” in honor of their distinctly lime-yellow blooms, small nutlets upon which are attached 3-inch long leafy wings.
I. Appearance and CharacteristicsÂ
Tilia cordata, the small-leaved lime or small-leaved linden, is a species of tree in the family Malvaceae, native to much of Europe. Other common names include little-leaf or littleleaf linden, or traditionally in South East England, pry or pry tree. Its range extends from Britain through mainland Europe to the Caucasus and western Asia. In the south of its range it is restricted to high elevations.
Tilia cordata is a deciduous tree growing to 20–40 m (66–131 ft) tall, diameter 1/3 to 1/2 the height, with a trunk up to 1 m diameter. The largest known trunk circumference was a specimen in Närke, Sweden, that measured 8.35 meters diameter at chest height. Lindar in Germany is said to be over 1000 years old. The bark is smooth and grayish when young, firm with vertical ridges and horizontal fissures when older. The crown is rounded in a formal oval shape to pyramidal. Branching is upright and increases in density with age. The leaves are alternately arranged, rounded to triangular-ovate, 3–8 cm long and broad, mostly hairless (unlike the related Tilia platyphyllos) except for small tufts of brown hair in the leaf vein axils – the leaves are distinctively heart-shaped. The buds are alternate, pointed egg shaped and have red scales.
It has no terminal bud. The small yellow-green hermaphrodite flowers are produced in clusters of five to eleven in early summer with a leafy yellow-green subtending bract, have a rich, heavy scent; the trees are much visited by bees to the erect flowers which are held above the bract; this flower arrangement is distinctly different from that of the Common Lime Tilia × europaea where the flowers are held beneath the bract. The fruit is a dry nut-like drupe 6–7 mm long by 4 mm broad containing one, or sometimes two, brown seeds (infertile fruits are globose), downy at first becoming smooth at maturity, and (unlike T. platyphyllos and also T. × europaea) not ribbed but very thin and easily cracked open.
II. How to Grow and Care
Sunlight
Small-leaved lime trees like plenty of sunlight and ideally should receive 3-6 hours of light per day. You can plant it somewhere outdoors with sufficient sunlight, such as the sunny side of a house. Sufficient sunlight promotes tree photosynthesis and is conducive to its growth. Small-leaved lime can also grow normally in partial shade, but too little light will reduce the number of flowers or even prevent blooming. Seedlings and saplings are more shade-tolerant. You can add a shade net in summer to protect small trees from too-strong light.
Temperature
Small-leaved lime trees prefer to live in a mild, moist environment and are very cold-hardy. The tree needs to be kept well-hydrated in moist soil for growth. However, it does not tolerate waterlogging. If living in standing water for a long time, the tree can lose leaves or its roots can rot. It will also grow poorly in arid and swampy areas.
Watering
Small-leaved lime does not tolerate drought and prefers moist soil, but also does not like stagnant water. In early spring when there is little rain, dry weather, and strong transpiration, you should provide the tree with more water. During the rainy season, you should stop watering. In the early flowering, late flowering, and fruiting periods, make sure to give it enough water. At the beginning of winter, water thoroughly once and then stop to promote lateral growth and lignification.
Small-leaved lime has a deep root system and generally does not need watering after maturing. However, it will need more water if it encounters a long-term drought. If the soil dries out easily, you can spread an organic mulch on the surface. This reduces evaporation and keeps the soil moist.
Soil
Small-leaved lime has a deep and wide root system and grows best in deep, fertile, well-drained soil. The trees will not grow well in poor soils or waterlogged, non-aerated, clay soils. If the soil is clay-like, add coarse sand to improve its water permeability. The tree prefers alkaline to neutral soils, and can also grow in slightly acidic soils. However, it cannot grow in marshes or saline soils.
Fertilizing
Mix organic or slow-release fertilizer with the soil before planting, and apply nitrogen fertilizer every 20 days after transplanting until early fall. You do not need to apply very much fertilizer each time – just spread it evenly. Mature trees demand less fertilizing, so you can follow up with some phosphorus and potassium fertilizer depending on the tree’s situation to promote the growth of the branches and leaves and improve the plant’s resistance. If the soil is fertile, no fertilization may be necessary.
Planting Instructions
You can buy small-leaved lime seedlings at a garden center. If transplanting the seedlings is necessary, do it in early spring, as this is when they are ready to germinate and grow and the roots can also easily heal and regenerate. After a period of normal growth from early spring to late fall, the tree will have recovered from any transplanting injuries and be prepared for overwintering.
It is best to plant small-leaved lime in the sun, in a 50 to 60 cm deep hole, with sufficient base fertilizer. After planting young trees, fill in the soil and compact it, or create a 10 cm-high soil mound at the bottom of the trunk to keep the soil around the young trees moist and warm. Then, water the tree thoroughly and follow up often to always keep the soil moist. You can also use sticks and iron frames to support the tree in case the wind threatens to blow it down.
Pruning
To keep the small-leaved lime trunk straight, start cutting lateral branches and one-third of the branches growing upward during the first winter or the spring of the second year after planting. Stop when the trunk height reaches 5 to 6 m. Every spring, completely cut off new shoots and branches that sprout near the ground on the trunk as early as possible.
Otherwise, these buds can consume too many nutrients and negatively affect trunk growth.
To shape the canopy nicely, prune the trees in winter. Cut overgrown lateral branches, thin the overcrowded branches, and completely cut off diseased and dry branches. To control the overgrowth of lateral branches growing to 20 cm, remove their top buds in early summer.
Propagation
Cuttings taken from younger lindens can be a more efficient way of propagation. Take these steps:
- In the summer, find a branch that has new growth on it. Find the part of the branch that’s semi-hardwood, meaning it’s not green, but not fully brown, either.
- With a sterile cutting tool, take a 6- to 8-inch long cutting.
- Remove the leaves except for two at the top of the cutting.
- Cut two vertical lines on the base of the cutting and dip the cutting into rooting hormone.
- Plant the cuttings into sandy beds outdoors or in gallon pots with drainage holes.
- Keep the medium moist.
- Roots should form within six weeks.
How to Grow from Seed
If you have only older little-leaf lindens, they may not be ideal for cuttings, so you may want to propagate with seeds. You’ll need lots of patience to propagate little-leaf linden from seeds and you may not find many to harvest. If you choose to go this route, take these steps:
- Collect seeds in the fall from the nutty fruits the tree drops.
- Remove seeds from inside nuts. These nuts can be very tough to crack to extract the seed.
- Scarification and stratification of the seeds is necessary. Start by soaking the seeds in hot water for 24 hours.
- Stratify the seeds for three months in baggies with sand.
- Either sow the seeds in small pots with potting mix and wait for the seeds to germinate, which can take nearly two years.
- Or sow the stratified seeds in the ground fall, winter, or early spring. Sow a group of 10 seeds every 20 to 30 feet.
Pests and Diseases
Common Pests & Diseases
Fortunately, this low-maintenance tree presents no serious insect or disease problems. Verticillium wilt is infrequent, though when this wilt does happen it can be fatal. Other diseases to keep an eye out for are powdery mildew, leaf spots, blight, canker, anthracnose, and Phytophthora.
In hot, dry periods spider mites may appear. Other pests that may feed on little-leaf linden trees include the following:
- Aphids
- Borers
- Caterpillars
- Gall mites
- Gypsy moth
- Horse chestnut scale
- Japanese beetles
- Lace bugs
- Leaf miner
- Sawflies
- Scale
Common Problems With Little-Leaf Linden
This low-maintenance shade tree poses very few problems. However, it can show signs when it’s experiencing a couple of problems.
Browning Leaves
Browning around the leaf’s margins is a result of leaf scorch. Leaf scorch is caused by drought conditions, which means that not enough water has made it to the leaves during hot summer months, but this condition typically resolves over time and does not kill the tree.
Stunted Growth
The tree is likely stressed. It may be planted where it is experiencing too much urban pollution, wind, and road salt spray.
III. Uses and BenefitsÂ
- Ornamental use
Small-leaved lime (Tilia cordata) is a popular ornamental tree loved for its elegant shape. It makes for a great shade tree due to its dense foliage. This is a good standalone ornamental garden tree and is also a popular street and avenue tree. Because of its dense foliage, small-leaved lime can also be trimmed into hedges and screens, making an eye-catching combination when paired with sweet gum or walnut.
- Culinary uses
Linden flower tea
In the countries of Central, Southern and Western Europe, linden flowers are a traditional herbal remedy made into an herbal tea called lime tea or linden tea in Britain, tilleul in France.
Honey
A monofloral honey is produced by bees using the trees and is widely used all over Europe. “Linden honey” is said to be nutritious and to have medicinal qualities.
Leaves
The young leaves can be eaten as a salad vegetable. Often cattle graze upon them.
- Linden wood
The white, finely-grained wood is not a structurally strong material but a classic choice for refined wood carvings such as those by Grinling Gibbons for medieval altarpieces, such as the Altar of Veit Stoss. Linden wood was the prime choice for the carvings in St. Paul’s Cathedral, Windsor Castle, and Chatsworth. It is also commonly used for lightweight projects such as carved spoons, light furniture, bee hives and honeycomb frames.