Leptospermum SCOPARIUM

Leptospermum SCOPARIUM - Broom tea tree, Manuka, New Zealand tea tree.

Can be trained as bonsai!

Leptospermum, or tea tree, is a genus of evergreen shrubs and small trees in the myrtle family (Myrtaceae), comprising about 85 species. The vast majority are endemic to Australia, with a few species native to New Zealand and Southeast Asia, where they colonize heaths, sandy plains, rocky slopes, and watercourse margins.

The shrubs branch densely, with rough bark on older branches that often peels in strips. The leaves are small, stiff, sessile or on very short petioles, rich in essential oils and releasing an agreeable fragrance when crushed.

The five-petaled flowers resemble tiny stars or wild roses, colored white, pink, or red, borne singly in leaf axils and densely coating the branches. The fruit is a dry woody capsule that splits into valves, containing numerous very fine seeds.

Leptospermum scoparium is a species native to New Zealand and southeastern Australia, including Tasmania, where it grows in scrub, on hillsides, and along bog margins. It is a densely branched evergreen shrub or small tree, readily shaped into a compact bush in cultivation. The leaves are small, stiff, lanceolate, sharply pointed, and emit a pronounced pleasant scent when bruised.

Flowering is profuse and long-lasting: branches are heavily smothered with five-petaled white, pink, or red blossoms, often double-flowered in garden selections. The fruit is a dry woody capsule that can persist on branches for years, eventually opening to shed dust-fine seeds.

Leptospermum seeds are extraordinarily minute, almost dust-like - which is how the genus received its botanical name. Soaking them is unfeasible: such fine seeds are easily lost in liquid and damaged, so the substrate itself is sanitized: before sowing, it is drenched with a weak solution of potassium permanganate and dried slightly. Scarification and stratification are not required.

Sowing is done on the surface of a moistened acidic lime-free substrate amended with sand or perlite - seeds are merely pressed gently onto the surface without burying. The sowings are misted from a spray bottle with a growth stimulant solution: SUPERthrive, HB-101, Aminozol, Epin, or Zircon, covered with plastic wrap or set in a propagator, and germinated in light away from direct sun at room temperatures of 20-24 °C (68-75 °F) with daily airing.

First seedlings under favorable conditions emerge in about 3 weeks; primary germination usually spans 1-2 months, while individual seeds may delay up to three months. The seedlings develop slowly and are sensitive to surface drying. Pricking out is carried out once several true leaves have developed, moving them into individual small pots with acidic substrate.

© Greeniverse. All rights reserved.

Leptospermum requires a bright, sunny position. In summer, moving the plant outdoors to a warm, well-lit spot shielded from strong winds is beneficial.

In winter, a cool, bright resting period at 4-10 °C (39-50 °F) is essential - this dormancy ensures prolific flowering the following season. In warm winter quarters, the plant etiolates, sheds foliage, and hardly blooms.

During active growth, watering is copious and must use soft water - Leptospermum cannot tolerate lime. Allowing the root ball to dry out completely is fatal, yet standing water is equally unacceptable. Misting with soft water during high heat is well received.

The substrate must be acidic, loose, and well-aerated, free of lime: ready-made soil for rhododendrons and azaleas is suitable, or a mix of acidic peat, leaf mould, and coarse sand with added perlite. Drainage is laid at the pot base. Repotting is carried out in spring as roots fill the pot, taking care to preserve the root ball.

Fertilizing is performed once every two weeks during active growth using a rhododendron fertilizer or another formula designed for acid-loving plants. Feeding is suspended during dormancy.

The plant tolerates pruning well and easily trains into a compact bushy specimen, which is why it is favored for bonsai culture. In addition to seeds, Leptospermum can be propagated by semi-ripe cuttings in spring.