Monster Cropping in Outdoor Grows
A high-stress training technique that uses flowering clones to produce bushy, multi-headed outdoor plants the following season.
Monster cropping is a real technique with real effects, but the internet has oversold it. Taking clones from a flowering plant and reverting them to veg does produce gnarled, bushy growth with lots of branching — that part is true. What's overstated is the yield math. Most of the gain comes from more bud sites and longer veg time, not magic. Outdoors, the main practical use is generating a free, late-season copy of a phenotype you already like.
What monster cropping actually is
Monster cropping is the practice of taking cuttings from a cannabis plant that is already in the flowering stage, rooting them, and reverting them back to vegetative growth under a long photoperiod (typically 18/6 or longer) or, outdoors, long natural daylight in spring and early summer.
Reverted plants look strange: leaves often come in with one, three, or five fingers instead of the usual seven to nine, and branching is dense and erratic. Once the plant fully re-vegetates, it develops a bushy, multi-headed structure with many potential bud sites Weak / limited.
Reversion (also called 're-vegging' or 'monstering') is well documented as a horticultural phenomenon in Cannabis sativa — the plant is a facultative short-day species and can be pushed back into vegetative growth by lengthening the photoperiod [1][2] Strong evidence. What is not well documented is the specific yield claim that monster cropping reliably outperforms a standard topped/LST plant. That part is grower folklore.
Why outdoor growers use it
There are a few legitimate reasons to monster crop outdoors:
- Phenotype preservation late in the season. If you find a standout plant in flower and didn't keep a mother, taking flowering clones is your only way to copy that exact genetics without seeds.
- Free bushy plants for next season. Cuts taken from a flowering indoor mother in late winter or early spring will revert during the long days of an outdoor spring, producing the dense, multi-branched structure many growers want for a SCROG or low-stress trained outdoor canopy.
- Naturally short, wide structure. Reverted plants tend to grow with shorter internodes and more lateral branching, which can be useful in windy or low-trellis outdoor setups Anecdote.
What it is not good for: a quick fix mid-season. Reversion takes 3–6 weeks before the plant grows normally again, and clones from flower root slower and less reliably than vegetative clones [3] Weak / limited. If your outdoor season is short, you do not want to spend a month waiting for a clone to figure out what month it is.
When to start
For outdoor growers in the Northern Hemisphere, the realistic timeline is:
- Indoor mother in flower: January–March. Take cuttings during weeks 2–3 of 12/12.
- Root and revert: 4–8 weeks under 18/6 or 24/0 indoors.
- Harden off: Late April–May, as outdoor daylight exceeds ~14 hours.
- Transplant outdoors: Once nighttime temps are consistently above ~10 °C / 50 °F.
Avoid taking cuts past week 4–5 of flower. Rooting success drops as the cutting commits more resources to bud development and less to root initiation Weak / limited. Trichome-heavy upper colas root worst; choose lower, less-developed side branches.
How to do it, step by step
- Pick a healthy donor in early flower. Weeks 2–3 of 12/12 is the sweet spot. The plant should not be heat- or nutrient-stressed.
- Select lower branches. Pick shoots that are 10–15 cm long, pencil-thick at the base, with at least two nodes. Avoid the dense, resinous tops.
- Cut at a 45° angle with sterile scissors or a scalpel, just below a node.
- Strip lower leaves and trim large fans to reduce transpiration. Leave 2–3 small leaves on top.
- Dip in rooting hormone (IBA-based gels or powders are standard; IBA improves adventitious root formation in many woody and herbaceous species) [4] Strong evidence.
- Place in a propagation medium — rockwool, peat plug, or aerated water (cloner). Keep medium at ~22–25 °C.
- Use a humidity dome at 80–90% RH for the first 7–10 days, venting daily.
- Light: 18/6 under low-intensity fluorescent or LED (~100–200 µmol/m²/s). Don't blast a reverting clone with high PPFD.
- Wait. Roots typically appear in 10–21 days — slower than vegetative clones. Reversion (normal serrated leaves returning) takes another 2–4 weeks.
- Pot up and train. Once the plant is producing normal foliage, treat it like any other veg plant: top, LST, or Mainlining as desired.
- Harden off and transplant outdoors when daylight is long and stable.
Common mistakes
- Taking cuts too late in flower. Past week 5, success rates fall off a cliff Anecdote.
- Using top colas. They look impressive but root poorly. Lower branches win.
- Over-watering rooting medium. Reverting clones are slow drinkers; soggy media causes rot.
- High light too soon. Reverting plants are metabolically confused. Strong light stresses them further.
- Expecting magic yield gains. A monster-cropped plant given the same veg time as a regular clone will not dramatically out-yield it. The yield bump people report is usually from longer total veg time and more bud sites — both achievable through standard topping and training Disputed.
- Skipping IPM. Flowering clones can carry powdery mildew, russet mites, or thrips from the flower room into your outdoor garden. Inspect and quarantine.
Related techniques
Monster cropping sits in a family of high-stress and structural training methods. Compare and consider:
- Topping: Simpler, more predictable way to get a multi-cola plant.
- Mainlining: Symmetrical manifold training; better for predictable yields.
- Low-Stress Training (LST): Gentle, reliable, and outdoor-friendly.
- Re-vegging a harvested plant: Different technique — same biological mechanism (photoperiod reversion) — but applied to the whole plant after harvest rather than to cuttings.
If your goal is bushier outdoor plants, topping + LST will get you 90% of the structural benefit with far less hassle. Monster cropping earns its place when you specifically need to clone a plant that's already flowering.
Sources
- Peer-reviewed Moher, M., Jones, M., & Zheng, Y. (2021). Photoperiodic response of in vitro Cannabis sativa plants. HortScience, 56(1), 108-113.
- Peer-reviewed Spitzer-Rimon, B., Duchin, S., Bernstein, N., & Kamenetsky, R. (2019). Architecture and florogenesis in female Cannabis sativa plants. Frontiers in Plant Science, 10, 350.
- Peer-reviewed Caplan, D., Stemeroff, J., Dixon, M., & Zheng, Y. (2018). Vegetative propagation of cannabis by stem cuttings: effects of leaf number, cutting position, rooting hormone, and leaf tip removal. Canadian Journal of Plant Science, 98(5), 1126-1132.
- Peer-reviewed Pacurar, D. I., Perrone, I., & Bellini, C. (2014). Auxin is a central player in the hormone cross-talks that control adventitious rooting. Physiologia Plantarum, 151(1), 83-96.
How this page was made
Generation history
Drafting assistance and fact-check automation are used, with a human operator spot-checking on a weekly basis. See how articles are made.
Related
- Low-Stress Training (LST) — A gentle plant training technique that uses bending and tying to flatten the canopy and ex...