Silk Tree 'Ernest Wilson' (Albizia julibrissin) - The Silk Tree with "Extra Winter Hardiness"

A touch of the tropics that endures even in our latitudes: The Albizia julibrissin 'Ernest Wilson' is a special selection of the Persian Silk Tree (also known as Mimosa Tree or Sleeping Tree). It combines the breathtaking, exotic beauty of the species with genetically enhanced, significantly improved winter hardiness. This cultivar owes its name to the famous plant hunter Ernest Henry Wilson, who discovered it in the climatically harsher regions of Korea in the early 20th century.

Scope of delivery: One young plant in a 7cm pot (approx. 10cm)

Botanical Highlights in Detail

Growth and Picturesque Silhouette

'Ernest Wilson' grows as a large shrub or small tree, typically reaching a height of 4 to 6 meters with a similar width. Its crown shape is particularly picturesque: it naturally forms a broad, flat umbrella-shaped crown that provides light, shimmering shade. The growth is often multi-stemmed and elegantly spreading, making it the perfect solitaire plant for patios or Mediterranean garden areas.

The Delicate Foliage & the Fascinating "Sleeping Movement"

The bipinnate leaves resemble fern fronds or mimosa. They give the tree an incredible lightness. A fascinating phenomenon is the so-called sleeping movement (nyctinasty): In darkness or rain, the countless small leaflets fold together in pairs, as if the plant were "going to sleep." The next morning, they open again in the sunlight.

Spectacular Flower Powder Puffs

In midsummer (July to August), the crown transforms into a sea of blossoms. The flowers consist mainly of long, silky stamens that look like pink powder puffs with a white base. They have a delicate fragrance and are a magnet for bees, bumblebees, and butterflies.

The Secret to Success: Location, Hardiness, and Proper Young Plant Care

The Perfect Location

For 'Ernest Wilson' to develop its full splendor and winter hardiness, warmth is essential.

• Light & Warmth: Full sun, warm, and wind-protected is a must. A south-facing wall or a sheltered courtyard are ideal. The tree needs summer heat for the wood to ripen well by autumn.

• Soil: The soil must be excellently drained. Sandy-gravelly, rather lean soils are ideal. Heavy, wet clay soils and waterlogging (especially in winter) inevitably lead to frost damage or root rot.

Winter Protection in Practice: The Safe Way for Young Plants

Here lies the crucial difference between theory and practice. Although 'Ernest Wilson' is considered the hardiest cultivar, established plants tolerate temperatures down to approx. -18°C (Zone 7a). However: This does not apply to young plants. In the first two to three years, the wood is still soft and the bark thin.

Therefore, the golden rule is: play it safe and bring young plants indoors for winter!

Here's how to safely get your silk tree through the critical juvenile phase:

1. Pot Cultivation: Keep the silk tree in a sufficiently large pot for the first few years. This makes overwintering straightforward.

2. The Perfect Winter Quarter: Since the tree sheds its leaves in autumn, it is in a deep dormant phase. It needs no light in its winter quarters. You can excellently overwinter the young plant in a cool, dark, and frost-free room such as an unheated garage, a cool cellar, or a shed. The temperature should ideally be between 5°C and 10°C, but must not freeze permanently.

3. Care in Winter: During this dormant phase, the plant needs almost no attention. Keep the soil only minimally moist so that the root ball never becomes completely bone dry. Do not fertilize.

The Way Outdoors and into the Open Ground

• Spring: As soon as (from about April/May) there is no longer a threat of severe continuous frosts, the tree can be moved outside again. Initially, acclimate it slowly to the sun in a semi-shady spot to avoid sunburn on the young leaves.

• Planting Out: Only when the trunk is significantly thicker and the wood is hard (after approx. 3 years), should the tree be permanently planted out. Be sure to choose spring for this. This way, it has the whole summer to develop a deep root system before spending its first winter in the garden (which you then protect with a thick layer of leaves over the root area).

Use in the Garden

The Albizia julibrissin 'Ernest Wilson' is a classic solitaire plant that needs space to unfold its umbrella-shaped crown. It is an ideal shade provider for seating areas and fits perfectly into Mediterranean or exotic gardens. Due to the light shade it provides, it can be well underplanted with sun-loving, drought-tolerant perennials (e.g., lavender, sage) or grasses.