Guide · Buyer guides
Indoor, greenhouse, light-dep and smalls: THCA grades explained
Indoor, greenhouse and light-dep name how the plant was grown; smalls names a bud size, which any of the three can produce. No regulator defines these grades as of 3 October 2026, so a grade label tells a buyer where to look, and the lot’s COA and size mix tell what was actually grown.
Reviewed 2026-10-03.
The grades side by side
| Grade | How it is grown | Light | Harvests per year (typical) | What varies most |
|---|---|---|---|---|
| Indoor | Closed rooms, electric light, controlled temperature, humidity and CO₂ | Electric only | Several room cycles | Grower skill; drying and curing |
| Greenhouse | Under glass or plastic film | Sun, sometimes with added electric light (“mixed light”) | 1–3 | Season, structure, pest pressure |
| Light-dep | Greenhouse or hoop house with blackout covers that shorten the day | Sun, controlled day length | 2–3 in a season | Timing of each run; late-season humidity |
| Outdoor (sun-grown) | Open field | Sun, natural day length | 1 | Weather in the last weeks before harvest |
| Smalls | Not a method: buds under about 1.5 cm, sorted from any grade | As the source grade | As the source grade | Which part of the plant they came from |
| Trim / shake | Leaf and broken material from trimming and handling | As the source grade | As the source grade | Leaf share; stem content |
Indoor
Indoor flower grows in closed rooms where the grower sets light, temperature, humidity and CO₂ for the whole cycle. Weather does not reach it. That control usually shows as dense buds, intact trichome coverage and a consistent look across a lot.
What indoor does not guarantee:
- Potency. Cultivar and harvest timing move THCA more than the room does. Read total THC on the lot’s COA.
- Cure. A well-grown indoor crop can be ruined by a fast dry. Check water activity (0.55–0.65 aw is the range in ASTM D8197) and smell for hay.
- Cost logic. Electricity and climate control make indoor the most expensive grade to produce. That cost is in the price whether or not the lot is better than a good light-dep run.
Greenhouse and mixed light
Greenhouse flower grows under sunlight filtered through glass or plastic. “Mixed light” means added electric light extends or strengthens the day. Structures range from glass houses with climate systems to simple hoops, so this grade has the widest spread in quality.
What to check:
- Pests and mold. A partly open structure lets more in. Ask for the microbial and mycotoxin results on the COA, not potency alone.
- Bud structure. Greenhouse buds are often less dense than indoor. Less density means more volume per gram, which matters if you sell by the jar.
- Lot consistency. Ask whether the lot is one harvest from one structure. Blends of several houses can vary bud to bud.
Light-dep
Light deprivation is a scheduling technique. Cannabis flowers when nights are long. A light-dep grower pulls blackout covers over the crop each evening to create long nights in mid-summer, so the plants flower months before the outdoor season ends. That allows two or three runs in one season and lets growers finish before autumn rain and cold.
What to check:
- Run date. Early runs finish in summer heat; late runs finish in autumn humidity. Ask which run the lot came from and when it was harvested.
- Moisture and mold. Late-season runs dry in humid air. Check water activity and the microbial panel.
- Trim. Light-dep volume often goes through machine trimmers. Look for flattened buds and stem length; see the stem test in Buying THCA by the pound.
Smalls
Smalls are buds below a size cut, commonly around 1.5 cm, sorted out of indoor, greenhouse or light-dep lots. A smalls lot should name its source grade: “indoor smalls” and “greenhouse smalls” are different products.
For a bulk buyer, smalls have three uses:
- Rolling. Smalls grind evenly and cost less per gram than large buds of the same grade.
- Value by weight. Small buds of a good grade can be better flower than large buds of a poor one, at a lower price per gram.
- Testing a cultivar. A smalls lot from a known grade shows the cultivar’s smell and smoke at a lower cost.
What to check:
- The COA for the smalls lot itself. Smalls often grow lower on the plant, where less light reaches, and can test lower than the top buds of the same harvest. A COA from the large-bud lot does not cover them.
- Leaf and crumbs. Small buds carry more sugar leaf per gram. Sift a sample and weigh the fines.
- Size floor. Ask for the smallest size included. “Smalls” that are mostly crumbs are shake.
Grade is not potency
The grade label describes the process. Potency is a separate measurement, and it is on the COA:
| Question | Where the answer is |
|---|---|
| How strong is this lot? | Total THC % on the COA (0.877 × THCA + delta-9 THC) |
| Is it clean? | Pesticide, heavy-metal, microbial and mycotoxin panels |
| Is it cured correctly? | Water activity on the COA or your own meter |
| How big are the buds? | Size breakdown by weight, or your own sort of a sample |
| Is it the lot I paid for? | Client lot number on the COA, the listing and the bag label |
What changes on 2026-12-11
The grade does not change the law. From 2026-12-11 (P.L. 119-37 §781; date set by H.R. 6500) the federal hemp test counts THCA, so flower of any grade above 0.3% total THC is no longer hemp in any state (CRS IF13136). In states with adult-use cannabis, the licensed-dispensary lane continues under state law. Flower sold in the hemp-retail lane after that date must test at or below 0.3% total THC on a dry-weight basis.
In this store
Every lot in the Shop is listed under one grade, with its COA linked on the product page, and every buyer sees the same HP and LB prices. Orders of 5 lb or more go on the same order sheet: see Large orders.
Sources
- 7 CFR 990.1: total THC definition used by USDA.
- ASTM D8197: water activity range for dried cannabis flower.
- CRS IF13136, 2026-08-17: the 2026 federal hemp definition.
Questions
What is the difference between indoor, greenhouse and light-dep THCA flower?
Indoor is grown in closed rooms under electric light with full climate control. Greenhouse is grown under glass or plastic with sunlight, sometimes with added lights. Light-dep is greenhouse or hoop-house flower whose daylight is cut with blackout covers to force flowering on a schedule.
Are THCA smalls a lower grade?
Smalls are a size, not a grow method. They are buds under roughly 1.5 cm from any grade. They often come from lower on the plant and can test lower than the top buds, so check the COA for the smalls lot itself.
Is there an official grading standard for THCA flower?
No federal or industry-wide grade standard exists as of 2026-10-03. Grade names are seller conventions. The COA, the size mix and the bud itself are the evidence.