Seidenbaum ∗ The 10 best care tips and pruning

origin

The silk tree, botanically Albizia julibrissin, is a species from the genus Albizia, which belongs to the mimosa family. It originally comes from large parts of Asia, from the Middle East from Iran to the last Asian corner in Japan. It colonizes temperate habitats and is therefore conditionally hardy.

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Due to its largely independent distribution, especially in moderate climates in the USA, the silk tree is also a neophyte - it has also found new homes outside of its original areas of origin. For example, it has long been widespread as an ornamental plant in the Mediterranean area.

Due to the increasingly warmer global temperatures, it will also be able to penetrate increasingly northerly regions in the long term. With us in Germany it can actually be cultivated without any problems in not too frosty corners of the country.

Origin at a glance:

Silk tree originally comes from near to Far Eastern areas
As a neophyte but also spread in temperate zones of the USA
Very popular as an ornamental plant in the Mediterranean
We can easily cultivate them in areas with moderate frost risk

growth

The silk tree grows as a graceful tree, sometimes its habit is also described as a shrub-like one. Its delicate, slender trunk is encased in a dark gray bark and branches are set relatively far below, which form a swinging, sweeping crown with filigree branches. Overall, a silk tree can grow up to 6 or 8 meters high, but only under particularly favorable conditions. It grows 20 to 40 cm per year and is usually only around 30 years old.

Growth characteristics in brief:

Slender, richly branched shrub to tree-like growth
Spreading, swinging crown
Moderate maximum height of 6-8 meters
Maximum age about 30 years

leaves

Apart from the spectacular bloom, the silk tree is a feast for the eyes for lovers of filigree structures. Because its leaves delight with elongated, egg-shaped, fine double pinnate leaves that swing gracefully and gracefully in the wind. The individual leaflets have a sickle-like shape of 7 to 18 millimeters and are in 4 to 15 pairs on the petiole. Their edges are finely serrated, and the central ribs are clearly hairy. The entire leaf reaches a length of about 7 to 15 centimeters.

The leaves also have a curious property: they close at night and enter a kind of sleep mode. They open again at daybreak. This is why the silk tree has the nickname “sleeping tree”.

Blade properties in brief:

Double pinnate leaves with a very graceful filigree appearance
Single leaves 7-18 mm long, total leaf length 7-15 cm
Finely toothed margins, central ribs hairy
Close at night - hence the nickname "sleeping tree"

blossoms

The flowers of the silk tree surpass its range of graceful beauty - it is not for nothing that they give its name to its main name. In fact, their very fine, smooth texture gives them a silky appearance.

They are characterized by long, filigree stamens that form a fluffy tassel from 2 ½ to 3 centimeters in size. They stand individually, in twos or threes on 3 ½ to 7 cm long inflorescence shafts and have a 3 to 6 mm long bract. With their striking play of colors, which changes from a yellow center on the stamens into an intense pink to scarlet pink, the flowers stand out splendidly from the medium green foliage.

When is the flowering time?

As with so many beautiful things, the duration of the silk flower bloom is limited and therefore all the more precious. The tree shows the admirable structure only between July and August. If you don't want to miss the flowering season, you should better plan your summer vacation in June or the postseason!

Which location is suitable?

The silk tree likes it sunny, warm and protected. In the garden, you should plant it in a sunny to partially shaded place that is not too exposed. A place facing south to southwest is ideal on a house wall, where the delicate vegetation is not disheveled by strong gusts of wind.

If you cultivate the silk tree in a bucket, a parking space on a sheltered, south-facing balcony is also conceivable.

Location requirements in brief:

Warm and sunny
As far as possible protected from sharp winds
Not exposed

What soil does the plant need?

The silk tree has a moderate to high nutrient requirement and therefore needs a humus soil. If you plant it in the garden, you should enrich the planting hole well with compost and horn shavings (€ 6.39 on Amazon *). A good permeability is also necessary - therefore mix in sand with the potting soil if possible, especially if the soil at the planting location is rather heavy. This also prevents excessive dewatering, which can have a damaging effect on the root system when there is frost.

If you want to keep the silk tree in the bucket, it is also important to provide the soil with a decent amount of organic long-term fertilizer, i.e. compost and / or horn shavings. A proportion of sand is not wrong here either, but a little expanded clay (€ 17.50 at Amazon *) is even better suited for a good drainage in the narrower tub plant base.

Overview of substrate rules:

Silk tree needs relatively nutritious soil
When planting, add compost and horn shavings (€ 6.39 at Amazon *)
Loosen heavy soils with sand for good permeability
In bucket culture, also humus soil, loosened up with sand or expanded clay

Plant out

For planting, first choose a suitable, sunny and sheltered location. Provide the excavated planting hole with a good drainage layer of sand and, if necessary, some gravel. Fill up the rest with humus, loosened sandy soil. The best time to plant is in spring after the last frosts.

Hardy

The silk tree is conditionally hardy - that is, it can only tolerate frost to a certain extent; limit values of around -15 ° C are specified. In very cold areas of the country, permanent outdoor cultivation can therefore be critical.

Young, newly planted specimens in particular should be protected prophylactically against cold damage in winter. It is best to wrap the delicate trunk with raffia or sackcloth. Cover the root area with similar material or with fir branches. With increasing age the silk tree becomes more and more insensitive to frost.

Protection against the cold is of course even more important in bucket culture, but it is also easier to achieve. Either wrap the bucket with burlap, etc., or place the plant in a wintering place where there are no two-digit minus temperatures, such as in a cold house.

To note:

Silk tree hardy to around -15 ° C
Young trees in particular should be protected preventively in winter by wrapping the trunk and covering the roots
Also wrap the specimens kept in the bucket and cover or place them in a place that is protected from the cold

Watering the silk tree

In the field cultivation you don't actually need to water the silk tree, at most in prolonged periods of drought.

With bucket culture, the plant is more dependent on your water supply. Make sure he gets regular water, either from the rain or from your watering can.

Fertilize the silk tree properly

You do not need to fertilize a planted silk tree. If the planting base is reasonably humic, that is sufficient as a nutrient base. In the case of poor or heavy soil, it is all the more important to supplement it with a lot of compost and horn shavings when planting and, if necessary, to top it up again in spring.

In the bucket culture, apart from the organic long-term fertilizer, you can also use a universal liquid fertilizer during the growth period, which you add to the irrigation water about every 2 to 4 weeks. Regular use of compost or your own nettle manure also works.

Overview of fertilizing:

In the field only organic long-term nutrient supply
During the growth period, add liquid fertilizer in the bucket every 2-4 weeks or add compost or nettle liquid from time to time

Cut the silk tree correctly

Whether you prune the silk tree depends on whether you want to keep it in the form of a bush or let it grow into a tree. If you prefer a shrubby, more compact and lower habit, prune the silk tree every spring. Do not proceed too intensely, just remove long, disturbing shoots. The silk tree can also tolerate radical pruning if necessary.

If you want to grow the silk tree into a pretty little tree - which is also particularly recommended for airy and atmospheric shading of a seat - cut out dried twigs at most after winter to give the plant a vital boost.

To note:

Silk tree can be cultivated in a shrub shape through regular spring pruning
When letting the tree grow out: no or only clearing cut

bonsai

Due to its good cut tolerance, the silk tree is also suitable for bonsaiists. It can easily be grown in a pot to form an artistically shaped mini tree. All common methods including wires can be used. However, you have to be careful when wiring - the wood of the silk tree is somewhat soft and, in combination with the rather rapid growth, wires grow in easily.

Multiplication

You can propagate the silk tree either by cuttings or by sowing.

Cuttings

With this tried and tested method, cut head cuttings from the crown in spring, defoliate them in the lower area and put them in a container with potting soil. For the rooting, keep the substrate evenly moist, possibly under foil. However, the ambient temperature should be relatively high, around 25 ° C is ideal.

Seed cultivation

But a silk tree can also be propagated well via seeds. You can easily get seeds yourself from the elongated fruits that the tree forms after flowering. You release the seeds from the fruit in autumn and dry and store them in a cool, dark place over the winter. In the spring, soak them in lukewarm water first. You can also roughen the seed coats a little beforehand - this makes it easier for the seedling to “hatch”.

The seeds prepared in this way are placed in planters with potting soil and only cover them lightly, as they are light germs. Place the planter bowls in a light place, also around 25 ° C. Keep the substrate evenly moist. A cover with foil or a mini greenhouse for a protected microclimate is recommended.

When the trees have reached a size of about 15 to 20 centimeters, you can transplant them, but not yet outdoors. To do this, you should be significantly larger.

Cultivation

See section “Propagation - Seed cultivation”

Is silk tree poisonous?

Unfortunately, the silk tree is not a completely harmless candidate for gardens in households with small children and pets. Its fruiting bodies and seeds contain toxins that can be dangerous to curious gardeners in summer and autumn.

tip

In order to promote straight growth in a sapling culture, it is advisable to tie the delicate trunk to a support post after planting. However, do not use a coarse cord, but rather a soft, wide jute ribbon to prevent it from growing in.

sorts

Albizia julibrissin Ombrella

The name of the variety A. j. Ombrella is somewhat misleading in this common spelling, as it suggests a particularly shadow-affine or shadow-throwing property. The notation A. j. Umbrella provides information: The specialty of this variety is the umbrella-like growth that distinguishes the crown. As a result, despite the naming that was not motivated by it, it is suitable as a romantic roofing over a shady place. Their long leaflets are very decorative with their numerous structures.

In July and August the pink, large clump flowers that are slightly scented appear.

The A. j. Ombrella can grow up to 8 m high and needs a sunny location. It is a little less hardy than its conspecifics and should be well protected in strong frost.

Albizia julibrissin Summer Chocolate

What does this variety have to do with chocolate? Very simple: its leaves are colored a reddish dark brown, so that they can awaken real chocolate dreams in summer. In terms of size and structure, they have the same feathery appearance as their conspecifics.

The A. j. Summer Chocolate also blooms in July and August - with light pink to pink-colored clusters of flowers that stand out very attractively from the brown foliage and spread a pleasant scent. With a maximum height of 4-6 meters, the variety is slightly smaller than the A. j. Ombrella.

Albizia julibrissin Ernest Wilson

This variety is refreshing with the graceful color contrast of its leaves and flowers. The filigree pinnate foliage is rich, muted dark green, from which the flowers stand out very attractively with their delicate pink and white base. The A. j. Ernest Wilson remains in a rather shrubby habit with a height of about 4 to 5 meters and a width of about 5 to 6 meters. Because of its particularly good winter hardiness, it is interesting for those who live in colder regions of the country.