Root cuttings are sections of root — not stem or leaf — taken during dormancy and used to produce new plants. Per NC State Extension, root cuttings work on a specific group of plants that have the capacity to generate adventitious shoots from root tissue. Not all plants can do this; the method is useless on species that lack this capability (most conifers, most annuals). But for the species that work, it is extremely simple: dig in winter, cut roots, plant in rooting medium, wait for new shoots.
How root cuttings work
Per Penn State Extension, root tissue in appropriate species contains meristematic cells (capable of cell division) distributed through the root parenchyma. When a root section is isolated from the parent plant and placed in a warm, moist environment, these cells produce adventitious shoots at the proximal end (the end that was closest to the crown) and adventitious roots at the distal end.
This polarity — shoots from the top, roots from the bottom — explains why orientation matters for thick root cuttings: they must be planted right-side up.
Timing
Per NC State Extension:
- Best window: Late fall through early winter (November—January in zones 5—7)
- Logic: Roots are dormant, fully charged with stored carbohydrates, and have maximum potential for regeneration
- Avoid: Taking root cuttings when the plant is actively growing — root reserves are depleted and success rates are low
In zones 6—7 (including Long Island, mid-Atlantic), late November through January is ideal. The ground is workable, plants are fully dormant, and root carbohydrate reserves are at peak. In zone 4—5, wait for a thaw window in November or December rather than digging in frozen soil — root tissue that freezes during collection has reduced cell viability. In zone 8—9, root cuttings can be taken as late as February before growth resumes.
Root cutting types
Thick-rooted species (roots 1/4 inch or larger)
Used for: Papaver orientale (Oriental poppy), Echinops (globe thistle), Anchusa, Verbascum, Phlox paniculata, Acanthus, Baptisia, Anemone × hybrida (Japanese anemone).
Method:
- Dig and expose roots in late fall—winter; the plant does not need to be fully removed — expose enough root to take cuttings, then replace soil
- Cut root sections 2—4 inches long
- Make a straight cut at the proximal (top) end; angled cut at the distal (bottom) end — this helps you keep track of orientation
- Plant vertically, right-side up (proximal end up), with the top end just at or slightly below the medium surface
- Cover with 1/2 inch of grit or coarse sand
- Root in cold frame or unheated greenhouse; do not provide warmth yet
- Shoots emerge in 4—10 weeks as temperatures warm in spring
Thin-rooted species (roots under 1/4 inch)
Used for: Primula denticulata (drumstick primrose), Phlox subulata (creeping phlox), Anemone hupehensis, Eryngium (sea holly), Limonium (sea lavender), Romneya (tree poppy).
Method:
- Dig and expose fine roots in late winter
- Cut 2—3 inch sections
- Orientation does not need to be maintained (lay horizontally)
- Place horizontally in rooting tray with 1/4 inch of medium over them
- Keep at 55—65°F; shoots emerge more quickly than thick-root cuttings
Species list
Per NC State Extension and University of Missouri Extension:
| Species | Root type | Notes |
|---|---|---|
| Papaver orientale (Oriental poppy) | Thick | The classic root cutting candidate; very easy |
| Anemone × hybrida (Japanese anemone) | Thin | Standard method; difficult to divide |
| Echinops (globe thistle) | Thick | Easy; 2-in. sections |
| Eryngium (sea holly) | Thin—medium | Lay horizontally |
| Phlox paniculata (garden phlox) | Thin | Good alternative to division |
| Primula denticulata | Thin | Very easy; horizontal placement |
| Acanthus (bear's breeches) | Thick | Easy; roots are persistent and very thick |
| Baptisia (false indigo) | Thick | Deep, thick roots; very easy to propagate |
| Anchusa azurea | Thick | Root cuttings are the standard method |
| Gypsophila paniculata | Thin—medium | Cuttings in autumn |
| Verbascum | Medium | Late winter; easy |
| Romneya coulteri (tree poppy) | Thin | West Coast only; standard method |
| Rubus idaeus (raspberry) | Thin | Root sections in pots; shoots emerge readily |
| Ailanthus altissima | Thick | Unwanted; this species regenerates aggressively from any root fragment — know this when removing it |
What doesn't work
Per Penn State Extension, root cuttings fail on:
- Most monocots (grasses, irises, lilies) — monocots lack the root parenchyma tissue needed to generate adventitious shoots
- Most conifers — with the notable exception of some Abies and a few other genera, conifer root tissue does not produce adventitious shoots reliably
- Most annuals — root systems are too small and the plants lack the perennial carbohydrate reserves that power shoot regeneration
- Species with contractile roots designed not to regenerate (many bulbous plants)
If root cuttings are not listed as a method for a species, they probably don't work. The presence of root suckering behavior in a mature plant — Ailanthus altissima, sumac (Rhus spp.), black locust (Robinia pseudoacacia), or raspberries — is a reliable indicator that root cuttings will succeed.
Rooting medium and storage
Per NC State Extension:
- Medium: 1:1 perlite + coarse sand for thick root cuttings; perlite alone or coarse sand for thin types
- Temperature during root development: 50—65°F; warmth is needed but not as high as stem cuttings
- Outdoor cold frame: Works well for winter-to-spring production; natural temperature rise in spring triggers shoot emergence
Avoid peat-heavy mixes — peat retains too much moisture and can promote rot in root cuttings before shoots emerge. If using a greenhouse for winter production, maintain 50—60°F rather than the 65—70°F typical for seedlings. Root cuttings stored in barely moist perlite at 35—40°F (refrigerator) can be held for 4—6 weeks before potting if timing is inconvenient — a useful option when garden conditions make December digging impractical.
Aftercare
Once shoots emerge (which happens before roots are well-developed on thick root cuttings):
- Move to brighter light — at least 6 hours of direct light or supplemental grow lights at 16 hours/day
- Do not over-water — roots are still establishing; the potting mix should feel slightly moist but not wet when you probe 2 inches deep
- Pot up individually when shoots are 1—2 inches tall and showing roots at drainage holes. Per NC State Extension, potting up before root development is adequate causes wilting when the cutting is removed from the humid rooting environment.
- Grow on in pots for 4—8 weeks before transplanting to the garden. In zone 5—7, root cuttings taken in December—January are typically ready for garden transplanting in April—May when soil has warmed and frost risk has passed.
Common problems
| Symptom | Cause | Fix |
|---|---|---|
| No shoots after 8 weeks | Cuttings taken during active growth; or wrong species | Timing is critical — collect in true dormancy only |
| Shoots wilt when they emerge | Root system insufficient; transplanted too early | Wait for more root development; keep in shade |
| Rot before shoots emerge | Medium too wet | Use coarser medium; reduce moisture |
| Planted upside down (shoots emerging from bottom) | Lost track of orientation | For thick cuttings, use the straight-cut-on-top system consistently |
Frequently asked questions
Does orientation actually matter? Per NC State Extension, yes, for thick-rooted species. Adventitious shoots emerge from the proximal end (top) and roots from the distal end (bottom). If planted upside down, shoots must travel through the rooting medium, which delays emergence and reduces success. Thin-rooted species placed horizontally avoid this problem.
Can I take root cuttings from trees? Some trees and shrubs will produce suckers from severed roots, and root cuttings from those species work. Per Penn State Extension, species that produce root suckers naturally — Ailanthus, poplar (Populus), sumac (Rhus), black locust (Robinia) — are amenable to root cutting propagation. Most ornamental trees are not.
How many root cuttings can I take without damaging the parent plant? Per Penn State Extension, take no more than 1/3 of the root system at one time. Dig carefully to expose roots without damaging the crown, take cuttings, and replace the soil. The parent plant will regenerate the removed roots within one growing season.
When should root cuttings be transplanted to the garden? Per NC State Extension, after 6—10 weeks in pots, once the plant has established a complete root-and-shoot system. In zone 6—7, this typically means plants rooted in December—January are ready for transplanting in April—May.
Sources
- NC State Extension — Propagation by root cuttings
- Penn State Extension — Root cuttings
- University of Missouri Extension — Plant propagation