Orchid cuttings: what works and what will not grow

When to propagate an orchid

Each method has its own timing, rather than a season. Moth orchids (Phalaenopsis) propagate in three ways, only two accessible to amateurs:

• natural keikis detach when roots reach 2.5–5 cm (1–2 in)¹;
• induced keikis start after flowering, with hormone paste on a spent spike node²;
• division of overgrown plants takes place during repotting¹.

The third route, growing spike sections on nutrient agar, needs a sterilized flask: a laboratory technique¹. All these methods produce plants identical to the parent¹.

Keikis: separating a spike plantlet

Detach a keikiA plantlet on an orchid spike or base, with its own leaves and roots; Hawaiian for “baby”. only once rooted. It arises from a dormant spike bud and develops roots soon after appearing¹. The RHS waits for several good roots before separation².

1. Wait for roots 2.5–5 cm (1–2 in) long, Stephen Batchelor's threshold in the American Orchid Society bulletin¹.
2. Cut with sterilized pruning shears, or detach with a sharp wrist movement¹. Disinfect blades between plants using flame or diluted bleach³.
3. Pot in orchid substrate, water lightly at first and mist leaves daily².

Left on the parent, a keiki keeps growing and may flower surprisingly quickly¹. A spike producing a keiki rather than flowers may have been too warm: spikes under 10 cm (4 in) grown at 28 °C (82 °F) or above may develop plantlets or lose buds⁴.

Une hampe qui porte un keiki ne se coupe pas : la page pruning an orchid explique où couper les autres.

Inducing a keiki with hormone paste

Special hormone paste on a spent spike node may produce a plantlet. The RHS calls this delicate work²:

1. With a scalpel, split the bractSmall brown triangular scale covering each spike node and protecting its bud. vertically over the node without cutting the bud beneath.
2. With tweezers, separate the bract's two halves.
3. Apply a little paste to the exposed bud.
4. Allow six to eight weeks: a plantlet may form.

Buy paste from specialist orchid suppliers; ordinary rooting hormone does not work². Choose an unused node, its bract still flat against the stem⁵.

Dividing an overgrown orchid

A moth orchid growing too high above its pot can be divided into top and base. It is monopodialGrowing upward from one growing point, without pseudobulbs or a rhizome, like a moth orchid., offering few division points: cut between the rooted base and top¹.

Batchelor recommends doing this at repotting, when plants are too tall for roots to fit properly in the substrate. The upper section takes its own roots, grown above the pot rim; remove a few lower leaves if necessary to avoid burying them¹.

A vigorous headless base often restarts one or more growing points, treated as keikis¹. Use a flame-sterilized, disinfected or new blade, then dust the wound with fungicide: a clean, dusted cut resists infection better¹.

Écorce neuve, pot à la bonne taille et tri des racines : repotting an orchid accompagne chaque division.

Spike sections, leaves and roots: what will not grow

Sources always describe new plants arising from nodes or growing points. None describes moth orchid leaf or root cuttings¹².

Spike sections do work, but not in water: a section bearing dormant nodes goes into a sterilized flask on nutrient agar; a node develops over a few months¹. None of the sources describes spike sections growing outside such flasks.

Bamboo orchids belong to another genus, Dendrobium; keikis grow along their canes¹. See bamboo orchid care.

Helping a rootless orchid regrow roots

An orchid that has lost its roots can regrow them under a bag, kept dry. Ned Nash of the American Orchid Society keeps air around leaves humid and substrate fairly dry, maintaining firmness until roots can feed the plant⁶:

1. Repot in the smallest pot accommodating remaining roots.
2. Water substrate, then cover with a plastic bag, held above foliage by a wire loop inserted in the pot.
3. Keep in shade until roots appear.

Allow a few days to a few weeks, longer with shortening days, from late September to January in the AOS source’s seasonal example, than in its spring or summer; interpret those months by local light and growth⁶.

Add your orchid: Floralens reminds you when to check keiki roots and repot, season by season in Pro mode. Get reminders

Frequently asked questions

How do I root an orchid cutting?

Moth orchids do not grow from leaf or root cuttings: separate keikis with roots 2.5–5 cm (1–2 in) long, or cut the rooted top from an overgrown plant¹. Pot keikis in orchid substrate, water lightly initially and mist leaves daily².

How do I help a rootless orchid grow roots?

Repot in the smallest possible pot, keep substrate fairly dry and cover with a plastic bag held above leaves, in shade, until roots appear. Depending on season, this takes a few days to a few weeks⁶.

How do I propagate a bamboo orchid?

Bamboo orchids are dendrobiums, rather than moth orchids: their keikis grow along canes and detach once roots form, as in moth orchids¹. See bamboo orchid for care.

What should I do with orchid roots?

Leave aerial roots extending beyond the pot: they are normal and should not be cut. At repotting, remove only dead, damaged or discolored roots⁷.

Can I root orchid cuttings in water?

No source describes moth orchid cuttings in water. Spike sections grow only in sterilized flasks on nutrient agar, a laboratory technique¹.