Published · Updated
How to Divide a Staghorn Fern Pup: Tools, Pulling, Cutting, Aftercare
Which tools to have ready, why most pups come off by pulling rather than cutting, how to cut when the roots are tangled too deep to see, and a day-by-day plan for light, water and air through the first two weeks.
With timing decided, what is left in dividing a staghorn fern (Platycerium) is the hands-on part: which tools to have ready, how to pull or cut a pup free, and how to care for it through the first two weeks. Timing is covered in When Is a Staghorn Fern Pup Ready to Divide?.
Tools
A sharp blade (a craft knife, grafting knife or thin paring knife), wiped with alcohol or passed through a flame. A small handful of fresh sphagnum, soaked and wrung to barely damp. A small board or cork slab. Fishing line or cotton thread. Cinnamon or charcoal powder for the cut is optional. Also useful: a small clamp with an angled tip for pups still in a seedling basket, a lever-style weeding tool for pups already mounted, and an orchid net pot to root a divided pup. Do not tear a pup off with blunt scissors; a ragged wound rots far more readily than a clean cut. Have the pot, netting and medium ready before you cut; a pup left lying out once it is off loses water fast.
How to divide
Most pups come off by pulling; keep the knife for pups whose roots are tangled too deep into the mother's old shield fronds and moss to see which way they run. If the mother's moss has dried hard, soak the whole mount first; damp roots are far less likely to snap. Find where the pup joins the mother, usually a short rhizome buried between old shield fronds and moss, and part the medium to see where its own roots run. If there is a plastic mesh backing, cut it open and lift the whole piece out. Take off only as many pups as you can mount the same day.
Pull, do not cut. Scissors are more likely to injure the mother's root system, and a damaged root system is less likely to throw another round of pups. For a pup still in a seedling basket, slide a small angled clamp in from below, close it behind the growing point where root meets crown, and pull outward; the whole pup comes away with its roots attached. If several are stacked together, take the outermost one first. For a pup already mounted, use a lever-style weeding tool instead, setting its notch against the spot right behind the growing point and prying gently.
Cut only when you cannot see the roots. Cut from the mother's side, taking a small piece of old tissue and the roots along with the pup — better to take a little too much of the mother's old shield than to nick the pup's growing point. One decisive stroke, not a sawing motion. Let both cuts dry in the shade for a few hours to a day; the mother's wound needs no dressing, only airflow.
A clump taken off whole: be ready to cut fronds. Lifting a whole clump off an old board always breaks roots, and what is left cannot supply the leaf area the plant had, so it starts sacrificing fronds on its own. Trim away exposed roots that would show on the face of the new board, keeping the dense root mass inside the medium; cut back excess or overlong shield fronds by about half, keep two or three fertile fronds, and clear out any dried buds and dead fronds. Roots recover and new fronds arrive faster this way, and the new growth sets itself to the new board, so the plant ends up better shaped than if you had kept every old frond.
Mounting the pup: wrap the roots in barely damp sphagnum, set it against the board with the growing point upright and tilted slightly forward, and tie it on. Do not pack the moss tight or pile it so high that it covers the shield.
The first two weeks
A pup with a full set of roots can go straight onto a board, or be potted first in an orchid net pot filled with sphagnum, packed firm enough that it does not shift. Or layer it: bark chunks at the bottom for drainage, coir in the middle (soaked and rinsed through several changes of water first to flush out salts), and a thin layer of sphagnum on top to hold moisture; go airier where the air is still, and keep more moss where things dry fast.
Days one to three: no soaking. The moss went on damp and carries the pup through; mist the air around it, not the growing point. Bright filtered light, never direct sun, and gentle air. Days four to seven: give the first light watering only once the moss surface has dried, from the side. A shield collapsing flat means the roots have not taken. Week two: hold the same filtered light, gentle air and barely damp moss; most sources advise no feeding for the first month. A shield that tightens again, or a new root tip, means the pup has taken; full establishment usually takes two to three months. The mother needs the same restraint — hold off on heavy watering until her wound has finished drying.
The three problems that most often come up after dividing — too few roots, twin crowns, a blackening mother — are covered in Four Problems When Dividing Pups; timing is covered in When Is a Staghorn Fern Pup Ready to Divide?. For getting more pups from the mother and patching it afterwards, see mother baskets.
FAQ
Will the pup die after I remove it? What is the success rate?
If it met the three conditions, the cut was clean, it got no soaking for the first three days and sat in filtered light with gentle air, most survive. The three main killers are forcing off a pup too small, nicking the growing point, and soaking plus direct sun straight after division. We do not quote a percentage; species and conditions vary too much.
Should I water a pup right after dividing it?
Do not soak it. The sphagnum it was mounted in is already damp and carries it through the first three days; mist the air around it, not the growing point. From day four to seven, give a light watering from the side only once the moss surface has dried. Most sources advise no feeding for the first month, and the pup is established once a new frond moves, usually after two to three months.
My plant has pups on both sides. Can I take them all off at once?
Do not cut both sides at the same time. Thinning the rhizome in the middle (growers call it the keel) leaves the crown prone to snapping. Take one side, let the mother recover and push new fronds, then do the other; if the buds are too crowded to cut cleanly, leave them for now.
I wrapped a newly mounted pup in cling film. How long before it puts out a new shield?
A common figure among growers is about two weeks under the wrap before the roots settle and a new shield starts, but that is only an average. Cool weather, weak light, very few roots at division, or a board that holds little moisture can stretch it to three or four weeks or more. Go by the plant, not the calendar: a shield that has firmed up with a new tip showing at its edge means it has taken; a frond that is limp all over means the roots have not gripped yet, so keep it in bright shade with a gentle breeze and barely damp moss. Keep the wrapped plant somewhere airy and shorten the wrap in summer. Full establishment usually takes another two or three months, so avoid heavy feeding and frequent moves in that time.
An imported plant arrived as a tight clump of several pups. Should I divide them while I replace the medium?
Yes. After a long journey the old medium is usually loose and has to be replaced anyway, so separating the pups in the same handling means the plant only has to recover once. Strip off the packaging, ties and old medium, count the pups and see which way each one's roots run, then start from the outermost one: take one at a time, with a single clean cut. Err toward the mother's side so that each pup keeps a thicker piece of root mass. If the pups sit around a central rhizome and you would have to cut both sides to free one, follow the one-side-at-a-time rule above. Fronds broken in transit or very long can be trimmed. Wrap each pup's roots in barely damp moss and mount it straight away, then leave it mostly alone and water sparingly for the first two weeks. Pups fresh from shipping have few roots and results vary from plant to plant; handling the whole clump together gives better odds overall.
Three or four buds have come up crowded together in one spot. Can I just cut them apart in one go?
Not while they are small. Check two things first. Are the shields between the buds already wrapping each other, and are the roots knotted into one mass? The tighter they are, the more likely a single cut injures both sides. And does each bud have roots and fertile fronds of its own? A bud that is too small has nothing to recover with once it leaves the mother plant. Some growers do it in stages: cut a shallow slit between the buds without lifting them, push a little sphagnum into the gap to wedge it open, then cut a little deeper every so often, and only separate them fully once each has its own fronds and roots. Decide by the state of each bud, not by how many buds there are; waiting one more season gives the whole clump much better odds.