Average Yield of a Cannabis Plant

Indoor vs. Outdoor Yields: Cannabis yields vary enormously with growing conditions. Under controlled indoor conditions (as in the photo below), a typical photoperiod plant will usually produce on the order of a few hundred grams of dried flower. One review reports indoor yields roughly 50–450 g per plant under good conditions. By contrast, outdoor-grown plants are generally much larger: a well-tended outdoor specimen often averages 300–1000 g (0.66–2.2 lb) per plant, with optimal plants easily exceeding 1 kg (2.2 lb). These ranges are consistent with many grower reports. In practice, indoor harvests “pale in comparison” to outdoor yields if plants are not space-limited. (One study found actual commercial yields ranged from <20 g/ft² to >60 g/ft², averaging ~39.5 g/ft², which corresponds roughly to 400–750 g/m² per cycle.)

Cannabis plants growing under HPS lights in an indoor grow room. Indoor yields per plant typically fall in the low hundreds of grams – for example, around 0.5–1.0 g per watt of light. In fact, experienced commercial growers often target up to 1 g of dried bud per watt of HID/LED lighting, though beginners often see only ~0.5 g/watt. In concrete terms, a 400 W HPS setup might yield ~200–400 g from one plant. By comparison, outdoor plants powered by full sun commonly produce far higher yields – multiple hundreds of grams per plant and even kilograms per plant for tall sativa genetics.

A mature outdoor cannabis plant in full bloom. Outdoors, plants have unlimited root space and sunlight, so exceptionally large specimens are possible. For instance, some sativa-dominant varieties can reach over 3 m tall and yield well over 1 kg per plant in ideal conditions. In contrast, typical indica varieties are bushier and usually yield closer to ~500 g per plant outdoors. On average, outdoor plants in a good climate and season often give hundreds of grams up to a kilogram each, whereas indoor plants (even big ones) more commonly yield in the few-hundred-gram range.

Photoperiod vs. Autoflower Yields

Cannabis genetics and flowering type also strongly influence yield. Photoperiod plants (which flower when day length is reduced) can be vegged indefinitely and generally produce larger plants and buds. One grower’s guide notes photoperiod plants average 400–700 g per plant (across indoor/outdoor). By comparison, autoflowering varieties (which switch to bloom on a fixed clock) typically remain smaller and faster-growing, yielding roughly 100–300 g per plant under comparable conditions. ILGM estimates indoor autoflowers often yield only about 50–120 g per plant (and outdoor autos perhaps 100–200 g). This reflects the fact that autoflowers have limited veg time.

However, photoperiod plants require more care (light-cycle management, training, etc.), so many growers choose autos for ease even at the cost of yield. In any case, adjusting light schedules can dramatically boost yields: one study found that lengthening the flowering photoperiod from 12 h to 14 h light (at least early in bloom) more than doubled cannabinoid yield in some varieties. This suggests that giving a plant more light hours during bloom often increases its final bud weight.

Factors Affecting Yield

Many variables impact yield. Key factors include:

Genetics/Strain: The single greatest factor. High-yielding varieties (often sativa-dominant or hybrid “monster” strains) can be capable of producing 1+ kg per plant outdoors. By contrast, many indica-dominant or fiber/hemp strains yield far less (hundreds of grams). Even within a strain, breeder claims vary; checking the expected max yield for your genetics is wise.

Lighting (Intensity & Spectrum): Light is fuel for bud growth. More powerful lights (or natural sun) generally mean more yield. A rule-of-thumb is ~1 g dry bud per watt in a well-optimized setup. Lights like HPS or high-output LEDs are commonly used. For outdoor growers, the sun provides roughly equivalent to thousands of watts.

Light Duration (Photoperiod): As noted, the length of daily light in flower can alter yield. Some research shows that extending bloom lighting (longer daylight) can substantially raise final yields. Indoors, growers often use 18/6 or 20/4 light cycles in veg and 12/12 in flowering, but novel schedules (e.g. 14/10) are studied for higher output.

Nutrients and Medium: Plants need balanced N-P-K and micronutrients. Both underfeeding and overfeeding can hurt yields. Hydroponic systems sometimes speed growth, but in practice soil-grown plants with compost/organics can match those yields with less risk. The medium size (pot size) also limits root growth, so larger containers generally allow bigger plants (up to ~15–20 L pots indoors, and large in-ground outdoors).

Grow Techniques: Training methods (topping, LST/Scrog, supercropping, Sea of Green, etc.) can dramatically improve yield by exposing more bud sites to light. For example, a well-executed Screen-of-Green (Scrog) can turn many small plants into a uniform canopy, often raising yield per watt or per square meter.