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The Grower's Glossary: Every Term You'll Meet, Decoded

LST, VPD, flushing, hermie, trichomes, DWC — the full dictionary of grow-speak so forums, videos, and our guides all make sense.

When
ANY
Level
beginner
Read
10 min
On this page6 sections

Grow culture speaks its own language. Here's the working dictionary — skim it once, then come back whenever a forum post reads like alphabet soup.

The plant itself

  • Cola — a main flowering bud site; the "top" every training method multiplies.
  • Node — where a branch/leaf meets the stem. Spacing between nodes signals light quality.
  • Fan leaves — the big solar panels. Sugar leaves — the small frosted leaves inside buds.
  • Calyx — the actual flower structure that stacks into buds. Pistils — the white hairs; they darken and curl as flower matures.
  • Trichomes — the resin glands (the "frost") holding cannabinoids and terpenes. Their color (clear → cloudy → amber) is the harvest clock.
  • Cotyledons — the first round seed leaves. They yellowing early is normal.
  • Taproot — the first root from a germinated seed. Snap it and the seed is done.

Genetics & seeds

  • Photoperiod (photo) — flowers when darkness hits 12 h. Autoflower (auto) — flowers on an internal timer regardless of light schedule.
  • Feminized (fem) — bred to produce ~99 % female plants. Regular seeds — 50/50 male/female.
  • Cultivar / strain — a named genetic line. Pheno(type) — an individual expression of it; two seeds of one strain can grow differently.
  • Hermie (hermaphrodite) — a stressed female growing male pollen sacs; can seed a whole tent.
  • Landrace — an old, region-native strain. Clone/cut — a rooted cutting, genetically identical to its mother.

Training & technique

  • LST (low-stress training) — bending and tying branches flat to multiply tops without cutting.
  • Topping — snipping the main tip so two colas grow instead of one. FIM — a sloppier top that can give 3–4.
  • SCROG — a screen/net the canopy is woven through for a flat, even table. SOG — many small plants flipped early.
  • Defoliation — strategic leaf removal for light and airflow. Lollipopping — stripping the shaded bottom third so energy goes topside.
  • Mainlining/manifolding — structured topping into a symmetrical hub of equal colas.
  • Super cropping — deliberately crushing/bending a stem softly to reset height (high-stress).

Environment & gear

  • VPD (vapor pressure deficit) — temp + humidity combined into one "how hard is the air pulling water from leaves" number.
  • RH — relative humidity. PPFD — light intensity actually hitting leaves. DLI — total light received per day.
  • Quantum board / bar light — modern LED formats. Blurple — old-style purple LEDs; usually a red flag.
  • Inline fan / carbon filter ("scrubber") — exhaust and smell control. Lung room — the room your tent breathes from.
  • Runoff — water that drains from the pot; its pH/EC hints at root-zone conditions.
  • EC / PPM — measurements of nutrient concentration in water.

Media & feeding

  • Medium — what roots live in: soil, coco coir, rockwool, or water (hydro/DWC).
  • Living soil / no-till — soil built to feed plants through microbial life, often water-only.
  • Super soil — heavily amended soil "cooked" in advance (see the Soil Lab).
  • Amendments — dry organic inputs: worm castings, kelp, alfalfa, bone/fish/crab meal, guano, rock dusts.
  • Top-dress — sprinkling amendments on the soil surface mid-grow. Tea — aerated microbe/nutrient brew.
  • Cal-Mag — calcium+magnesium supplement; the usual fix for LED-era rusty spots.
  • N-P-K — nitrogen, phosphorus, potassium: the three numbers on every fertilizer.
  • Lockout — nutrients present but chemically unavailable (usually pH). Flush — plain-water reset of a salted-up medium.
  • Mycorrhizae (Mykos) — root-partner fungi that extend nutrient reach.

Harvest & after

  • Flip — switching photos to 12/12 to start flower. The stretch — the height explosion in flower weeks 1–3.
  • Fade — the healthy late-flower yellowing as the plant spends its reserves.
  • Wet/dry trim — trimming at chop vs. after drying.
  • Cure — the slow jar-finish that turns "decent" into "excellent." Burp — opening jars briefly during cure.
  • 62 % pack — two-way humidity packs for jars. Loupe — the magnifier for trichome checks.
  • Larf / popcorn — small airy under-canopy buds. Bud rot (botrytis) — mold inside dense colas; the late-flower nightmare.

Bookmark this one — every other guide on the site will read twice as fast.

Deep dives on key concepts: pH for beginners · VPD & environment · nutrient deficiency chart · topping, FIM & mainlining · reading trichomes · drying & curing

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