Mongolian lime (Tilia mongolica) is an ornamental tree that is popular for its small size, making it ideal for gardens. Its serrated leaves offer several seasons of interest as they emerge as bronze, turn to green in summer, and then to yellow in the fall. The common name, “Mongolian lime,” and specific epithet, mongolica, refer to this plant’s native range in Mongolia.
I. Appearance and Characteristics
Tilia mongolica Maxim., commonly known as Mongolian lime, is a tree native to mountains of northern China, growing up to elevations of 1200–2200 m.
Mongolian lime is a small slow-growing deciduous tree of rounded, compact habit, usually reaching < 10 m in height. The dense, twiggy growth and glabrous reddish shoots bear leaves 4–7.5 cm long, typically coarsely toothed with 3–5 lobes, superficially resembling ivy or maple leaves. The emergent leaves are bronze, turning glossy green in summer, and bright yellow in autumn. The greenish-white flowers are borne in clusters of 6–20 in June and July.
History of discovery and cultivation
1863: In the summer the mongolian lime was first collected by Pere David on slopes of the Baihua mountain in the Taihang mountain range about 120 km west to Beijing city center. The specimens collected by David can be seen in the herbarium of the National Museum of Natural History, Paris.
1871: 12 July it was collected by Nikolay Przhevalsky on the southern slope of Muni-ula in western part of the Yin Mountains in Inner Mongolia. One of Przhevalsky’s specimens is held as an isotype in the herbarium of the Kew Gardens, London.
1877: Again collected on the Baihua mountain by Emil Bretschneider.
1880: Karl Maximovich published the first scientific description of the tree based on the specimens collected by Przhevalsky and Bretschneider.
1880: Bretschneider sent seed to the Jardin des Plantes at Paris.
1882: Bretschneider sent seed to the Arnold Arboretum at Boston.
1896: A tree in the Jardin des Plantes, raised from the seed sent by Bretschneider, flowered. Some of the gathered seed were sent to the Kew Gardens.
1907: A tree raised in the Kew Gardens flowered while only 1.5 m high.
1913: Тhe mongolian lime was introduced to commerce in the UK by Harry Veitch at the Coombe Wood Nursery from material collected for him by William Purdom in northern China.
II. How to Grow and Care
Mongolian lime is considered an easy-to-care-for species, adaptable to various conditions. Key care needs include full sun to partial shade exposure and well-drained soil. Special care points for mongolian lime involve ensuring adequate water during dry spells and providing mulch for root protection. Pruning is minimal, only to remove dead or diseased branches.
Sunlight
Mongolian 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. Mongolian 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
Mongolian 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
Mongolian lime thrives in conditions that mimic its native environment, which includes moderate humidity and occasional rainfall. This species is adapted to withstand brief periods of drought, maintaining a balance between moisture retention and tolerance to drier spells. Accordingly, mongolian lime benefits from watering once every two weeks. As an outdoor plant often found in temperate regions, mongolian lime’s growth cycle is attuned to the changing seasons, requiring less water during its dormancy period in colder months.
Soil
Mongolian 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 mongolian 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 mongolian 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 mongolian 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
Mongolian lime is a member of the Tiliaceae family, showcasing heart-shaped leaves and fragrant floral displays. When propagating, cuttings are an effective method. For successful root development, select healthy semi-hardwood stems. Utilize a rooting hormone to enhance root growth, and consider a well-drained soil mix for planting. Adequate moisture and indirect sunlight support robust growth during the rooting phase. Patience is essential as mongolian lime can take time to establish a strong root system.
Transplanting
For mongolian lime, the prime period for relocating is nestled between the warm embrace of late spring and the nurturing onset of early summer, ensuring optimal root establishment. Choose a site with well-drained soil, shielded from harsh winds. If needed, enrich the planting area with organic matter to encourage vitality.
III. Uses and Benefits
Mongolian lime wood is slightly soft and easy to work. It can be used to make general furniture, interior decoration, and other materials. If you keep bees, the tree’s linden flowers are a good place for them to collect nectar. Mongolian lime nectar is abundant and of good quality, which can be used to make honey jams and snacks. You can also gather linden flowers in the summer and dry them to make linden tea.
