Mongolian lime

Mongolian lime: how do you recognise it?

Habit

Small to medium deciduous tree, 10–12 m tall and 6–8 m wide, with a dense, rounded crown.

Leaves

Small, 4–8 cm, deeply triangular-lobed and toothed; glossy dark green, yellow in autumn.

Flowers

Small, scented, creamy-yellow flowers in little clusters, in July.

Fruit

Small nutlets hanging from a pale bract, ripening in autumn.

Bark

Grey and smooth on young trees; becomes finely furrowed with age.

Flowering: July · Plants: March–April and October–December · Pruning: December–February

Why grow it?

• At 10–12 m it suits smaller gardens and streets better than the big limes.
• Scented flowers in July, a feast for bees and bumblebees.
• Fine, glossy, deeply lobed leaves give an airy, elegant effect.
• Little trouble with aphids and sticky honeydew: tidy above a terrace or parking space.
• Fully hardy and not fussy about soil.

Mongolian lime: where does it grow best?

• Sun to partial shade; it flowers most freely in sun.
• Sand, loam or clay, acid to chalky, preferably humus-rich and well drained. It tolerates drought fairly well but not wet feet.
• Normally moist soil; water young trees in dry summers.
• Allow for a spread of 6–8 m and keep at least 5 m away from buildings, pipes and paving.
• Fairly sheltered from strong, dry wind.

Light

Sun and partial shade

Soil type

Sand, loam or clay

Acidity

Not fussy

Moisture

Normal

Size

12 m tall, 8 m wide

Hardiness

Hardy (to -35 °C)

Goes well with

• Crocus: Flowers in February–March under the still bare crown.
• Hosta: Big leaves in the partial shade beneath the tree.
• Ferns: Fresh, green underplanting.
• Hydrangea: A shrub that flowers in the light shade next to the tree.

Mongolian lime: when and how to plant it?

Plant in March–April and October–December.

1. Plant in March–April or from October to December, when the soil is neither frozen nor too wet.
2. Dig a hole twice as wide as the root ball but no deeper, and loosen the sides.
3. Set the tree at the same depth as in the nursery or container; the root flare must not be buried.
4. Fit a stake and tie the trunk loosely with a tree tie. Check it every year.
5. Water in with 15–20 litres straight away and spread a 5 cm layer of wood chips or leaf compost around the base, keeping it clear of the trunk.

Care

Water

For the first 2–3 years give a thorough 15–20 litres every week in dry spells. After that it usually copes on its own.

Feeding

Not needed in good soil. In poor soil spread a layer of compost under the crown in spring.

Mulching

A ring of wood chips or compost keeps the soil moist and the grass away from the trunk.

Trunk care

Do not mow or trim right up against the trunk; wounds in the bark open the door to disease.

Fallen leaves

Fallen leaves can be reused as mulch or added to the compost.

Tip: It is a good choice if you want a lime without the huge crown of the common lime: it stays around 10–12 m. Still do not plant it too close to the house; these roots need room too.

Mongolian lime: when to prune it?

Pruning months: December–February.

When: Prune during dormancy, from December to February, on a dry, frost-free day. A young tree is shaped in its first years; after that it needs hardly any pruning.

How:

• Train a straight trunk with a single leader and remove competing leaders.
• Take out dead, crossing and damaged branches; cut just outside the branch collar.
• For a taller clear trunk along an avenue or above a terrace, remove the lowest branches gradually over several years.
• To keep the crown even, light trimming is enough.

Caution: Never prune during flowering in July, when the bees are in the tree. Leave major work to an arborist.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Seed

The seed needs a long winter rest. Sow the nutlets outdoors in autumn; germination can take a year or two.

Grafting

Nurseries propagate selected forms by grafting onto a rootstock. This is usually too difficult at home.

Mongolian lime: how does it get through the winter?

Hardy to −35 °C.

• Fully hardy, to about −35 °C: no protection is needed in Belgium.
• Protect young trunks in their first winters with a guard against rabbits and deer.
• It grows too big for a pot and belongs in open ground.

Diseases and pests

• Aphids and honeydew: It suffers less than other limes. If you do see sticky leaves, ladybirds and hoverflies usually clear them.
• Drought stress: Brown leaf edges or early leaf fall after a hot summer. Give young trees enough water and mulch the soil.
• Leaf spot: Brown spots on the leaves in a damp summer. Clear the fallen leaves in autumn; treatment is rarely needed.
• Bark damage: Rabbits and deer gnaw young trunks and mowers damage the base. A tree guard solves this.

Through the year

• January: Prune on a frost-free day. Check stake and tie.
• February: Last chance to prune before spring.
• March: Planting is possible again. Apply mulch.
• April: Plant until mid April. Water new trees in dry weather.
• May: Leaves fully out. Watch for aphids.
• June: Water young trees in dry weather.
• July: Flowering: scented blossom and plenty of bees. Do not prune.
• August: In drought, water young trees every week.
• September: Fruits ripen; collect seed if you wish.
• October: Yellow autumn colour. Planting is possible again.
• November: Leaf fall; clear the leaves or use them as mulch. Plant.
• December: Plant in open weather. Start winter pruning.

Good for wildlife

Bees

Nectar and pollen for honeybees and wild bees.

Did you know?

• The species name mongolica refers to Mongolia, where the tree grows wild.
• The leaf is so deeply lobed that many people mistake it for maple rather than lime.
• Lime flowers are visited by many kinds of bees, and lime honey is known worldwide.