Linden tree: growing & caring for Tilia trees
Linden trees are easy to care for, cope well with warm, dry weather and are a sign of ancient woodland. Here is everything you need to know about the lime tree.
Linden trees (Tilia), also known as lime trees or basswood trees, were once very common in Britain. Today, they are considered a remnant of ancient woodland, and if you spot one in the woods, it could be a sign that you are in a rare habitat. The grand trees tend to be found in urban spaces and parks nowadays instead.
Lime trees are extremely hardy, insect-friendly and come in a wide range of sizes – so there is something for everyone! Read on to find out how to plant linden trees in your garden, what their characteristics are and how to care for them.
- Flowers, leaves and characteristics of linden trees
- The most beautiful linden species and varieties for the garden
- Planting linden trees: location and method
- Caring for your linden tree properly
- Common pests and diseases of the linden tree
Flowers, leaves and characteristics of linden trees
Linden trees are part of the mallow family (Malvaceae). There are about 50 species worldwide, found natively in the temperate regions of North America, Europe, and Asia. In the UK, the main species of Linden tree are the large-leaved lime (Tilia platyphyllos), the small-leaved lime (Tilia cordata) and a hybrid of the two, called the common lime (Tilia x europaea).
Tip: A special feature of the Linden tree is its foliage, which falls in autumn. This foliage not only smells good, but decomposes well, making excellent compost.
Linden trees grow between 15 and 40 metres high, depending on their species and variety, and can live for over 1000 years. This is in part due to their ability to resprout, even after damage and disease.
The leaves of many linden species are heart-shaped, which is why linden trees are also called trees of love. Their fruits, which are round-oval nuts, fall off whole, and their dry-skinned bracts help disperse seeds in the wind.
In their first years of growth, lime trees develop a taproot. With age, however, the plant forms secondary roots and its root system becomes heart-shaped. These secondary roots are important, because lime trees have little protection against fungi, which can decompose their trunks, and leave them hollow. The secondary roots grow down through the trunk, carrying water and nutrients, so that the fungal attack does not kill the tree.
Despite this life-line, linden trees are uncompetitive, which is why they are rarely found in modern forests.
When do linden trees blossom?
Linden trees need hot summers to flower and seed. The large-leaved lime begins to flower in June, followed by the common and small-leaved limes in July, signalling the beginning of high summer. With up to 60,000 creamy white, sweet-scented flowers, linden trees are not only beautiful, but a haven for insects. For bees in particular, lime trees are a great source of pollen when most other trees are faded.
The most beautiful linden species and varieties for the garden
In addition to species like Silver Linden (Tilia tomentosa) and American Linden (Tilia americana), Europe is home to large-leaved, small-leaved and hybrid lindens. There are several varieties of these lime species, each differing in size and crown width.
Small-leaved linden trees often have splendid foliage in autumn. They do not require a lot of nutrients and are adaptable to different soil types. What is more, these lindens tend to tolerate urban climates and short dry periods well.
- Tilia cordata ‘Greenspire’: One of the best known linden varieties in cities. Growing 13 to 20 metres tall, ‘Greenspire’ has an oval, closed crown, that grows up to 13 metres wide. This variety is particularly drought and heat tolerant.
- Tilia cordata ‘Rancho’: Reaching only 8 to 12 metres tall, ‘Rancho’ is even smaller than ‘Greenspire’. Ideal for the garden, this variety grows slowly. It is wind resistant and usually unaffected by aphids. The crown of ‘Rancho’ is initially narrow, but rounds with age, growing up to 8 metres wide.
- Tilia cordata ‘Monto’: One of the smallest varieties of the small-leaved linden, ‘Monto’ grows very slowly and reaches a height of only 4 to 5 metres. This variety has a unique, spherical crown. ‘Monto’ rarely flowers or fruits, and is susceptible to leaf spot diseases.
Large-leaved linden trees
Large-leaved linden trees are much more demanding than their small-leaved counterparts. They require evenly moist, deep, and nutrient-rich soils; and are susceptible to frost, dry air, drought, air pollution and soil salinity. As such, these varieties are only suitable for select locations.
- Tilia platyphyllos ‘Fastigiata’: With steep, upright branches, this variety has an interesting, narrow, pyramidal crown. Under the right conditions, ‘Fastigiata’ reaches 25 to 30 metres tall, but remains only 3 to 4 metres wide.
- Tilia platyphyllos ‘Zelzate’: Reaching only 12 to 20 metres tall, ‘Zelzate’ is a small but fast-growing, disease-resistant variety. It is characterised by its dense, oval to pyramidal crown, which grows 4 to 5 metres wide.
- Tilia platyphyllos ‘Örebro’: Its name speaks to its Swedish heritage: ‘Örebro’ has been propagated in Sweden since 1935. It grows slowly, to a height of 15 to 18 metres, with side branches that grow upright at first, and then bend down after about 10 years, giving the tree its oval crown. Notably, this variety flowers profusely with an intense fragrance.
Some other interesting species
- Henry’s lime (Tilia henryana): This species, originally from China, grows up to 12 metres tall. Henry’s lime has distinctive, hairy, deeply serrated leaves and does not flower until August, making it very popular among beekeepers. When young, this species must be protected from frost. However, older trees are fine to about -12°C.
- Japanese linden (Tilia japonica): Japanese linden is native to eastern China and Japan and is very similar to the small-leaved linden. In fact, the only difference between the two is that Japanese linden has twice as many chromosomes as small-leaved linden.
- Common lime (Tilia x europaea): Common lime is a natural cross between the large-leaved and small-leaved linden. It grows up to 40 metres tall and has a variable, broad crown. It is one of the more frost-resistant species, but is susceptible to aphid infestation.
Tip: Large-leaved and small-leaved linden trees can look alike. However, there are some differences. For example, small-leaved linden leaves are hairless on their upper sides, while large-leaved linden leaves are not. Small-leaved linden fruit tends to be soft and crushable; large-leaved linden fruit is hard and ribbed. Finally, the bark of small-leaved lindens is often raised, ribbed, and deeply furrowed in early life. Meanwhile, large-leaved linden bark remains finely furrowed, even at midlife.
Planting linden trees: location and method
Lindens are undemanding trees that cope well with an occasional dry spell. However, they do prefer warm and sunny to semi-shady locations, and grow best in well-drained and well-aerated soil.
Importantly, there are a few differences between large-leaved and small-leaved linden trees. For instance, small-leaved lindens tolerate alternating moisture, while large-leaved linden trees need more warmth, nutrients, and less acidic soil. Because of this, it can be useful to limewash the large-leaved limes before planting them, and at regular intervals afterwards.
In sum: think carefully about which linden tree suits your location before planting! There must be enough space for the tree’s crown to spread. And, because many linden trees are attacked by aphids when flowering, you should not place parking spaces, pools, or seating areas under any linden trees. The aphids do little harm to the tree, but can secrete a sticky honeydew.
Planting linden trees:
- The best time to plant a linden tree is in autumn, before the first frost.
- Dig a hole at least twice the size of the root ball.
- Mix the dug soil with a good potting soill, like our peat-free Plantura Organic All Purpose Compost.
- If the tree is root-balled, open the cloth or wire mesh but do not remove it. Remove the tree from the pot, and place it in the hole so that the root neck is even with the soil surface.
- Stake large linden trees using two stakes.
- Fill the hole with the soil mixture and press down with your foot.
- Form a watering ring from excess soil and water generously.
- In the following year, water the tree during dry spells.
Tip: Plantura Organic All Purpose Compost is an excellent aid to linden trees that are planted in heavy and dense soil or light and sandy soil. Packed with organic matter, this compost loosens the earth and increases its water and nutrient storage capacity.
Linden tree in a pot: It is possible to grow a linden tree in a pot. However, there are several things to bear in mind. First, it is important to select a suitable linden variety. For instance, ‘Monto’ and ‘Green Globe’ are suitable potted linden varieties because they are small and grow slowly.
The tree should be protected in winter, watered regularly and have a large enough pot throughout its life; as the tree grows, so too should its pot. In fact, after a few years, the pot should hold at least 600 litres! Further, your linden pot should drain water well, to avoid waterlogging.
Finally, it is vital to use a good potting soil. Our Plantura Organic All Purpose Compost is an excellent choice. It is peat-free, which saves up to 60% CO2 in production.
Caring for your linden tree properly
Overall, linden trees are very easy to care for. In fact, once their root system is well established, they do not need watering or fertilising. The trees are also very tolerant of pruning and can be shaped into almost any form.
Lindens in winter: As a rule of thumb, lime trees are very hardy. However, in their first few years, the trees can be susceptible to the cold. As such, it is a good idea to place some mulch around the tree to protect it in its early years.
Watering and fertilising linden trees
Lindens must be watered during hot, dry spells when they are young. However, as they grow, the trees become more independent.
Once they are large enough, you will not need to fertilise them either, although young, large-leaved lime trees are happy to receive a few extra nutrients in spring. Our Plantura All Purpose Plant Food, which slowly releases feed over three months, is a great choice for this. Alternatively, you can use ready-made compost.
- Perfect for a variety of plants in the garden & on the balcony
- Promotes healthy plant growth & an active soil life
- Long-lasting fertiliser that is free from animal products - child & pet friendly
Pruning linden trees
It is possible to grow linden trees in rows as a hedge. However, it is worth noting that linden trees do not store any tannic acids or toxins in their wood, which makes them very susceptible to insect and fungal attack. This susceptibility is exacerbated with pruning. To compensate, lindens sprout vigorously after being cut.
The best time to prune limes is in early autumn or spring, before flowering. This is because the tree stores less material in these months, and therefore sprouts less. To prune the tree, remove old and rotten branches completely, and then shape as desired.
Note: If you prune a linden tree frequently, it can become hollow from the inside out, leaving it unstable in old age. Without pruning, limes grow into large, stately trees.
Common pests and diseases of the linden tree
Most linden tree diseases are caused by fungi. The three most common diseases are:
- Leaf browning: Leaf browning is caused by the pathogen Apiognomonia tiliae. It appears as brown spots on the linden’s leaves. These spots have dark edges and often originate from insect galls. If you find these spots, rake up infected, fallen leaves and destroy them, pruning any infected branches when the tree is dormant.
- Cercospora leaf spot: Caused by the fungus Cercospora microsora, cercospora leaf spot is characterised by small, 3-4 mm large, brown spots. The spots have dark edges and form on leaves. These spots can occasionally appear on the stems and branches of a lime tree as well. If you spot them, rake up infected, fallen leaves in autumn and destroy them to avoid reinfestation in spring, and prune out any twigs that display necroses.
- Branch dieback: Caused by the fungus Stigmina pulvinate, branch dieback prevents linden trees from sprouting in spring and causes many branches to die. Usually linden trees can survive branch dieback, and, by the end of the growing season, the tree should have a closed crown again. However, this does not mean that the tree is healthy. Unfortunately, there are no standard measures to control for branch dieback, but vigorously pruning the infected branches can help.
Some pests also attack linden trees. Here are three of them:
- Aphids (Aphidoidea): Aphids like the linden aphid (Eucallipterus tiliae) like to attack linden trees and feed by sucking fluid from the tree. Aphids secrete a sticky fluid called honeydew, which attracts bees. However, it also sticks to everything underneath the linden trees and can hinder photosynthesis by causing sooty mould fungi to colonise. Usually, this problem is self-regulating, thanks to ladybirds. However, small, young linden trees can be treated with a neem preparation.
- Linden burncow beetle (Ovalisia (Scintillatrix) rutilans): It can be difficult to identify a linden burncow beetle infestation in its early stages. Symptoms include: the withering of leaves in the crown, irregular swelling of the bark and sap flow. It is only in the later stages that the tree’s bark will burst open and parts will fall off. If you look closely, however, you may also notice the pest’s slanted boreholes that appear on the tree’s trunk. Because linden burncow beetles are protected, the best control against linden burncow beetle is to ensure your tree is as healthy as possible.
- Linden spider mite (Eotetranychus tiliarium): Linden spider mites are almost invisible to the naked eye. However, you should be able to spot their webs. For prevention, a greased band can be placed around the trunk in winter. Alternatively, if your tree is already infested, use natural enemies of spider mites, such as predatory mites (Mesostigmata), for control.
Caring for linden trees in a nutshell:
- Young linden trees need to be watered regularly during dry periods.
- Fertilise young trees in spring.
- If you want your linden tree to have a certain shape, it is best to prune it in early autumn or spring.
- Various pathogens and fungi can attack linden trees. Infestation is often tolerated.
You can propagate linden trees via seeds or cuttings. However, growing the tree from seed requires years of patience, and has a low success rate. This is because linden seeds develop strong germination inhibitors that must be overcome.
Propagating a linden tree from a shoot is much easier because the trees sprout new shoots on their own from superficial roots. Once you have found such a sapling, dig it out carefully with a spade, and plant it in its new location or temporarily in a pot.
If you do not want to wait until you find a linden sapling by chance, you can stimulate your tree to sprout from the base of its trunks. This method is also known as propagation via offshoots.
- Make shallow cuts in the trunk. This will stimulate the tree to sprout.
- Pile substrate around the lower part of the trunk, like wood chips, bark mulch or moss.
- Keep the substrate moist until new shoots grow. These will form their roots in the piled substrate.
- In autumn, carefully inspect the roots of any new shoot. If the roots are well developed, carefully cut off the sapling and transplant it into a pot filled with a more nutrient-rich soil, like Plantura Organic All Purpose Compost.
- Provide your sapling with plenty of water and nutrients, before moving it into the ground. It is also important to protect young trees from frost during their first winters.
Linden trees are not only beautiful, and a haven for insects, but their leaves and flowers can be used in food and medicine. Read our article on the uses of linden trees to find out more.