How Much Weed Does One Plant Produce?
“How can I grow as much weed as possible?” You know that’s what’s on your mind when you ask or wonder about plant yield. Old and new marijuana growers (and scientists and politicians ) alike want to know how to get the highest yield per plant and per grow. Planning and practice can make a huge difference– especially when you are only growing one plant!
But, ultimately let’s not forget that the cannabis plant is a sentient being. She’s alive! Her growth is dependent on many factors and the same plant can produce a pound in one situation and a couple grams in another. Below we will detail the known factors that impact yield and potency, discuss where things can go wrong, and where things can grow right.
What is yield? (wet vs. dry yield)
Yield is the amount of weed you get when you harvest your marijuana plants. This is only the buds themselves, removed from the stems. This is most often measured once your marijuana buds are dried and trimmed. This is generally measured in grams, ounces, and pounds. The “lid” is not a used measurement anymore.
One of the most know measurements currently is an 1/8th (of an ounce) which is 3.5 grams. This is commonly found in dispensaries as well as something one might purchase from their friendly neighborhood weed guy. In this picture below, only two perfectly grown and cured buds were needed to reach this weight!
Wet and dry cannabis does not weigh the same.
Immediately upon harvesting, your buds will be quite heavy. That’s because, like humans, freshly harvested cannabis flowers are 75 – 80% water by weight. Once dried and cured, the actual harvest you get is about ¼ of the wet weight. So, if your harvest weighs out at an ounce at first cut, when it’s all said and done, you will have a quarter ounce of homegrown weed to smoke.
To estimate your dry yield from your wet yield, just multiply the wet yield by 0.25 to get an idea of what you’ll have to share with your friends (or stash away for yourself)!
This varies slightly depending on if you grew a sativa-dominant or an indica-dominant strain. Sativas are notoriously more airy so if you weigh your sativa harvest wet, you will get 20 – 22% dry. Indicas tend to be a bit chunkier so if you weigh your indica harvest wet, you will get 22 – 25% dry.
Yield vs. Potency
Yield is an important factor to consider because cannabis is an annual crop; there’s only one harvest per plant. After harvest, the plant is dead and returns to compost. Yield is the weight of the buds that you harvest. Yield should not be confused with the potency of these hefty green nuggets. Potency is the strength of the cannabinoids found in the trichomes on your cannabis buds.
In other words, you can have a high yield of low potency buds. Or you can have a low yield of high potency buds. In a perfect world, you’d get a high yield of high potency buds and we are going to discuss how to make that happen!
What to do to increase your weed plant’s yield?
Let’s get the most out of your homegrown medical (and recreational) marijuana. Best plant performance and yield are the result of growing the right strains under the right conditions. The most important factors being: light, plant density, fertilizer, temperature, duration of the flowering growth stage, and plant variety. In sum, the TLDR version is:
blast as much light as you can afford, grow less plants to fill your space appropriately, feed your plants just enough but not too much, keep the space not too hot and not too cold, don’t harvest early, and don’t buy shit genetics
(bag seed gamblers are included!)
Light to Increase Weed Plant High Yield
The yield from an indoor-grown cannabis plant largely depends on the light the plant receives. Cannabis plants, being photosynthesizers, receive all their energy to function from light.
The type, quality, and amount of light you provide your marijuana plant directly influences yield and should not be taken lightly (see what we did there?)
Sunlight is the most powerful light us earthlings have access to, so if you are able to give your plant direct sunlight, do it! Sunshine is also free, and that is a big plus. The only downside is that we cannot control cloudy or rainy days and winter makes it challenging to grow with the limited amount of sunlight (the freezing temperatures also don’t help).
Moving to an indoor grow environment, w hen it comes to lighting fixtures, it does not benefit you to get the cheaper option. And we know how challenging it is to pick the right light- – there’s so many options out there! (incandescent, CFL, HPS, LEDs)
We do not encourage growers to use incandescent light bulbs when growing indoors. To get enough energy for your plant, the bulb would put off too much heat and not be fun to see on your electric bill. CFL bulbs are equally useless. Stick to new technology to protect your plants and your wallet.
While HPS light fixtures are historically the choice for those who want to maximize their indoor cannabis crop harvest, they are slowly fading out from commonplace. An experienced grower can expect to harvest a gram of weed from each watt of HPS light provided to the plant. This means that if the light is a 400-watt HPS bulb, then 400 grams of weed could potentially be harvested. However, LED light technology is getting more advanced. LEDs are: 1) cheaper to run than HPS and 2) run cooler than HPS which also lowers the cost of air conditioning and 3) reduces the likelihood of burning your plants with too much light.
When choosing an LED light fixture for your weed plants you are up against a surplus of options and information.
The most important metrics to look for in a lighting fixture are PPF, PPFD, and energy usage/efficacy . If none of these are present, you may want to look at a different fixture.
PPF, PPFD, and photon efficiency are measurements related to PAR. PAR is photosynthetic active radiation. PAR is not a unit of measurement but instead defines the type of light needed to support photosynthesis.
PPF is how much PAR a lighting system produces each second. This is not often listed as it does not show how much of the measured light actually lands on your plants but is a useful metric to calculate how capable a light fixture is at creating PAR.
PPFD (photosynthetic photon flux density) is the measurement of how much PAR actually arrives at your plant. This is a spot measurement and is typically highest at the center point beneath the light and decreases as light ripples outwardly. This changes with the distance away from the plant. Ideally, the higher the better but a single measurement won’t tell you much– you want the average taken from many measurements throughout the coverage area.
Photon efficacy is a way of defining how good a lighting fixture is at converting the electrical energy into PAR light that your plant can actually consume. This is not often listed in the spec sheet for most lights. Instead, most light manufacturers list the wattage, either total electrical watts or watts per square foot. Knowing the wattage is good to budget the main cost of your indoor cannabis grow. But the wattage doesn’t give the best information about the quality of light as watts are a measurement of the energy coming into the light fixture (from your electric bill) where photon efficacy is how good the light is at giving your plant energy.
We suggest paying attention to whether or not the company you want to buy a light from lists the actual wattage or the watt equivalent. (Hint: if they are only disclosing the watt equivalent, the light is most likely not strong enough for cannabis.)
LED wattage and incandescent wattage aren’t the same.
Many LEDs are marketed with their “incandescent equivalent” wattage, referring to the brightness of the LED. For example, a 10 watt LED may say “75 watts” on the package and in fine print say that the brightness is equivalent to a 75 watt incandescent. But for growing cannabis, you’re going to want an actual real 75 watts (or higher!) from your LED lamp .
Can I give my weed plant too much light?
The answer in fancy, science talk:
Effectively, within the range of practical indoor PPFD levels—the more light that is provided, the proportionally higher the increase in yield will be. Therefore, the question of the optimum LI [light intensity] may be reduced to more practical functions of economics and infrastructure limitations: basically, how much lighting capacity can a grower afford to install and run? – Victoria Rodriguez-Morrison, David Llewellyn , and Youbin Zheng
In plain English:
No, not really! For a vegging photoperiod cannabis plant, you will want to give her a minimum of 18 hours of light a day– some give 20 hours or even keep the lights on 24/7. We know that a lot of good growth happens during the dark period when the cannabis plant has time to rest so we suggest either a 18/6 or 20/4 light cycle for photoperiod cannabis in the vegetative stage.
Same goes with autoflowering cannabis, with an autoflower seed indoors, you’ll want to give it 20 hours light / 4 hours darkness each day.
When it comes to using light to maximize yield, maximize the light intensity to meet your budget.
Grow Less Cannabis Plants to Get More Weed
In some ways you may think that if you pop more marijuana seeds or get more clones that you will get a bigger harvest in the end. This is not always true.
Each cannabis plant wants her own space. Planting more than one seed in a pot leads to competition between plants for the shared nutrients and reduced yields. As seen in this photo below where two seedlings starved each other and both ended up dwarfed:
The size of the container that you grow your pot in matters, too. Outdoor plants have the potential of reaching extreme oak tree size when planted directly in good soil (which can be hard to find) and allowed to flourish in an open, sunny space. Indoor cannabis plants, become much like a goldfish in either a fishbowl or an aquarium or an ocean, you will grow a different size plant from the Mini Complete Pot Grow Kit (1/2 Gallon) to the Medium Complete Pot Grow Kit (5 gallon) or the Large Complete Pot Grow Kit (35 gallon) . The bigger pot, the bigger plant (and the more pot).
Growing in a grow tent, consider the total space as well as the size of your containers. It may sound like a good idea to pack a small 24’’ x 48’’ x 60’’ tent with as many pots as possible but this will limit the canopy space for your plants to fill. Best to give each pot space for the plant to fill out.
Growing less plants means:
- A longer vegetative stage. This means bigger plants. Bigger plants have bigger harvests and higher yield. When growing photoperiod cannabis indoors, it is time to transition your tent to flower when the tips of the leaves of each plant begin to touch. More plants touch each other faster.
- Less plants to manage! You know each one personally and can tell when even the slightest thing is off which means you can catch pests and diseases before they become a major problem. This also means that you will have more time for defoliation and advanced pruning techniques to maximize your yield!
In the same space with a 600 watt HPS lamp, you can either get 37.5 grams from 16 plants, 150 grams from four plants, or a pound from one single plant! Don’t compromise on plant density; the more space you give a single plant, the more she can blossom.
Best Grow Mediums to Maximize Harvest
Yield can also vary based on the particular grow medium you use. It has been clearly documented that using hydroponics to grow marijuana can result in 20 percent more yield compared to using soil indoors.
Hydroponics increases yield because it is the most efficient way to feed plants. The grower supplies all the nutrients that the plant would naturally need to find for herself in the soil.
But, hydroponic systems are also 1) more expensive to set up and run, 2) can take time (like several runs) to dial in a nutrient feeding schedule and 3) can go wrong if your plants are fed too much.
At the simplest level, fertilizers come in varying NPK (Nitrogen, Phosphorous, and Potassium) formulations. Fertilizers that are richer in nitrogen are ideal for the vegetative phase, and those richer in potassium are better suited to the flowering phase. Growing hydroponically you need to know which nutrients your cannabis plants need during their different stages of growth and have that ready.
Whether you opt for organic, inorganic, or a mixture of the two is more of a personal decision. The important thing is that your marijuana plants receive enough nutrients to give you a higher yield per plant, but never too much. Unlike light intensity, there is a sweet spot for nutrients when it comes to growing marijuana. Too much of a good thing can negatively impact your plants. Unfortunately, finding the right balance between enough nutrients and excess nutrition usually comes with experience.
Soil grown marijuana can pull down some epic yields as well. But not all soils are created equal. For example, one person growing marijuana in loam soil may have a richer harvest since loam soil is easy for the roots to penetrate. On the other hand, clay soil could lead to a dismal yield since it doesn’t easily drain and can be quite compact, making it difficult for cannabis roots to grow.
That’s why a Pot for Pot specially formulated our Superb Soil to contain just the right amount of nutrients to maximize cannabis growth. With a Pot for Pot kits, there’s no need to add additional fertilizer because their soil has everything your plant needs from seed to harvest . It isn’t just easy to use, it’s optimized for marijuana growth.
Our complete grow kits include everything you need to go from seed to your very own supply of high grade medical cannabis.
Cannabis sativa L.
Source: James A. Duke. 1983. Handbook of Energy Crops. unpublished.
A multiple-use plant, furnishing fiber, oil, medicine, and narcotics. Fibers are best produced from male plants. In the temperate zone, oil is produced from females which have been left to stand after the fiber-producing males have been harvested. Leaves are added to soups in southeast Asia. Varnish is made from the pressed seeds. Three types of narcotics are produced: hashish (bhang), the dried leaves and flowers of male and female shoots; ganja, dried unfertilized inflorescences of special female plants; and charas, the crude resin, which is probably the strongest. Modern medicine uses cannabis in glaucoma and alleviating the pains of cancer and chemotherapy. More resin is produced in tropical than in temperate climates. Lewis lung adenocarcinonoma growth has been retarded by oral administration of delta-9-tetrahydrocannabinol, delta-8-tetrahydrocannabinol and cannabinol, but not by cannabidiol. (J.N.C.I. 55: 597-602. 1975). The delta-9 also inhibits the replication of Herpes simplex virus.
Medicinally, plants are tonic, intoxicant, stomachic, antispasmodic, analgesic, narcotic, sedative and anodyne. Seeds and leaves are used to treat old cancer and scirrhous tumors. The seed, either as a paste or as an unguent, is said to be a folk remedy for tumors and cancerous ulcers. The decoction of the root is said help remedy hard tumors and knots in the joints. The leaf, prepared in various manners, is said to alleviate cancerous sores, scirrhous tumors, cold tumors, and white tumors. The plant is also used for mammary tumors and corns (C.S.I.R., 1948-1976). Europeans are said to use the dregs from Cannabis pipes in “cancer cures” (Watt and Breyer-Brandwijk, 1962). Few plants have a greater array of folk medicine uses: alcohol withdrawal, anthrax, asthma, blood poisoning, bronchitis, burns, catarrh, childbirth, convulsions, coughs, cystitis, delirium, depression, diarrhea, dysentery, dysmenorrhea, epilepsy, fever, gonorrhea, gout, inflammation, insomnia, jaundice, lockjaw, malaria, mania, mennorhagia, migraine, morphine withdrawal, neuralgia, palsy, rheumatism, scalds, snakebite, swellings, tetany, toothache, uteral prolapse, and whooping cough. Seeds ground and mixed with porridge given to weaning children.
Most varieties contain cannabinol and cannabinin; Egyptian variety contains cannabidine, cannabol and cannabinol, their biological activity being due to the alcohols and phenolic compounds. Resin contains crystalline compound cannin. Alcoholic extracts of American variety vary considerably in physiological activity. Per 100 g, the seed is reported to contain 8.8 g H2O, 21.5 g protein, 30.4 g fat, 34.7 g total carbohydrate, 18.8 g fiber, and 4.6 g ash. In Asia, per 100 g, the seed is reported to contain 421 calories, 13.6 g H2O, 27.1 g protein, 25.6 g fat, 27.6 g total carbohydrate, 20.3 g fiber, 6.1 g ash, 120 mg Ca, 970 mg P, 12.0 mg Fe, 5 mg beta-carotene equivalent, 0.32 mg thiamine, 0.17 mg riboflavin, and 2.1 mg niacin. A crystalline globulin has been isolated from defatted meal. It contains 3.8% glycocol, 3.6 alanine, 20.9 valine and leucine, 2.4 phenylalanine, 2.1 tyrosine, 0.3 serine, 0.2 cystine, 4.1 proline, 2.0 oxyproline, 4.5 aspartic acid, 18.7 glutamic acid, 14.4 tryptophane and arginine, 1.7 lysine, and 2.4% histidine. Oil from the seeds contains 15% oleic, 70% linoleic, and 15% linolenic and isolinolenic acids. The seed cake contains 10.8% water, 10.2% fat, 30.8% protein, 40.6% N-free extract, and 7.7% ash (20.3% K2O; 0.8% Na2O; 23.6% CaO, 5.7% MgO, 1.0% Fe2O3, 36.5% P2O5, 0.2% SO3; 11.9% SiO2, 0.1% Cl and a trace of Mn2O3). Trigonelline occurs in the seed. Cannabis also contains choline, eugenol, guaiacol, nicotine, and piperidine (C.S.I.R., 1948-1976), all listed as toxins by the National Institute of Occupational Safety and Health. A beta-resercyclic acid derivative has antibiotic and sedative properties; with a murine LD56 of 500 mg/kg, it has some aritiviral effect and inhibits the growth of mouse mammary tumor in egg embryo (Watt and Breyer-Brandwijk, 1962).
Non-users may suffer muscular incoordination (9 of 22 persons), dizziness (8), difficulty concentrating (8), confusion (7), difficulty walking (7), dysarthria (7), dry mouth (7), dysphagia (5), blurred vision (5), and vomiting (1), following oral ingestion of THC disguised in cookies (MMWR, October 20, 1978). People working with the plant or the fiber may develop dermatitis. In larger doses, hemp drugs may induce catalepsy, followed by coma and DEATH from cardiac failure (C.S.I.R., 1948-1976).
Annual herb, usually erect; stems variable, up to 5 m tall, with resinous pubescence, angular, sometimes hollow, especially above the first pairs of true leaves; basal leaves opposite, the upper leaves alternate, stipulate, long petiolate, palmate, with 3-11, rarely single, lanceolate, serrate, acuminate leaflets up to 10 cm long, 1.5 cm broad; flowers monoecious or dioecious, the male in axillary and terminal panicles, apetalous, with 5 yellowish petals and 5 poricidal stamens; the female flowers germinate in the axils and terminally, with one 1-ovulate ovary; fruit a brown, shining achene, variously marked or plain, tightly embracing the seed with its fleshy endosperm and curved embryo. Fl. summer; fr. late summer to early fall; year round in tropics. Seeds weigh 1.5-2.5 gm/100 seeds.
As Cannabis sativa has been cultivated for over 4,500 years for different purposes, many varieties and cultivars have been selected for specific purposes, as fiber, oil or narcotics. Drug-producing selections grow better and produce more drug in the tropics; oil and fiber producing plants thrive better in the temperate and subtropical areas. Many of the cultivars and varieties have been named as to the locality where it is grown mainly. However, all so called varieties freely interbreed and produce various combinations of the characters. The form of the plant and the yield of fiber from it vary according to climate and particular variety. Varieties cultivated particularly for their fibers have long stalks, branch very little, and yield only small quantities of seed. Varieties which are grown for the oil from their seed are short in height, mature early and produce large quantities of seed. Varieties grown for the drugs are short, much-branched with smaller dark-green leaves. Between these three main types of plants are numerous varieties which differ from the main one in height, extent of branching and other characteristics. Reported from the Central Asia, Hindustani, and Eurosiberian Centers of Diversity, marijuana or cvs thereof is reported to tolerate disease, drought, fungus, high pH, insects, laterite, low pH, mycobacteria, poor soil, slope, and weeds. (2n = 20, 10, 40.)
Native to Central Asia, and long cultivated in Asia, Europe, and China. Now a widespread tropical, temperate and subarctic cultivar and waif. The oldest use of hemp seems to be for fiber, and later the seeds began to be used for culinary purposes. Plants yielding the drug seem to have been discovered in India, cultivated for medicinal purposes as early as 900 BC. In medieval times it was brought to North Africa where today it is cultivated exclusively for hashish or kif.
Plants very adaptable to soil and climatic conditions. Hemp for fiber requires a mild temperate climate with at least 67 cm annual rainfall, with abundant rain while seeds are germinating and until young plants become established. Thrives on rich, fertile, neutral to slightly alkaline, well-drained silt or clay loams with moisture retentive subsoils; does not grow well on acid, sandy soils. Of the many types of hemp, some are adapted to most vegetated terrains and climates. Ranging from Cool Temperate Steppe to Wet through Tropical Very Dry to Wet Forest Life Zones, marijuana is reported to tolerate annual precipitation of 3 to 40 dm (mean of 44 cases = 9.9 dm), annual temperature of 6 to 27°C (mean of 44 cases = 14.4), and pH of 4.5 to 8.2 (mean of 38 cases 6.5) (Duke, 1978, 1979).
Propagation mainly by seed. Experimentally, drug plants have been propagated from cuttings but such plants do not come true as to drug content of parent. Seeds stored in cool, dry place remain viable for up to two years. Hemp seed sown as early in spring as possible. Before sowing, land is plowed (in fall) several times to a depth of about 20-23 cm and repeatedly harrowed the land. In spring the land is harrowed again and rolled, making a firm tilth over the entire surface. In some areas a first plowing is done in the fall and red clover or lupin planted; in January or February a second plowing turns these under as a green-manure. Generally sown in March, seeds germinate at low temperature, but not below 1deg.C. Rate of seed sown varies with type of fiber desired; for coarse fiber for cordage and coarser textiles, 2.5 bu/ha is used; for finest fibers, 7.5-10 bu/ha used. Seed sown by machine in rows from 12 cm upwards, placing the seed at depth of 3.5 cm at rate of 40-60 kg/ha. In many countries seed sown broadcast. When grown for seed (oil), seed sown by drills; then such plants sometimes reach height of 5.3 m with thick stems up to 5 cm in diameter, much-branched. For fiber, stems up to 2 m tall and 0.5 cm in diameter are best; larger stems tend to get woody and have lower fiber content. Besides, they are more difficult to handle during harvesting, retting and scutching. Plants require little cultivation, except for weeding during early stages of growth. Hemp grows rapidly and soon crowds out weeds. After plants are 20 cm tall, weeding is abandoned. Hemp tends to exhaust the soil of nutrients. Some nutrients are returned to the soil after plants are harvested. On medium fertile soils a dressing of farm manure or a green-manure crop should be added and turned under. Chalk, potash, or gypsum may be applied to the soil to add the needed nutrition. Sodium nitrate and ammonium along with potassium sulfate have a beneficial effect on the fiber crop. Fiber-producing plants should always have plenty of proper nutrients, especially nitrogen, which is the most important element needed. Irrigation is seldom practiced.
Hemp is ready for harvest four to five months after planting, rarely earlier for some varieties. Harvesting depends on the climatic conditions, the variety of hemp grown and whether the crop is being grown for hemp or seed. In temperate areas, hemp is usually harvested from mid July to mid August. Both male and female plants look alike until they flower; then the male plants turn yellow and die, whereas the female plants remain dark green for another month until the seed ripens. Male plants are ready to harvest for fiber when the leaves change from dark green to light brown. The best yield of fiber (and only male plants are used) is then obtained. Hemp is harvested when the staminate flowers are beginning to open and shed their pollen. Seed is harvested from the female plants when most of it falls off when the plant is shaken. Best time of day to harvest seed is in early morning when fruits are turgid and conditions damp. As fruits dry out by mid-day, seed loss increases due to shattering. Usually stems are cut and the seeds shaken out over canvas sheets or beaten with sticks to extract the seeds. For fiber, hemp plants are cut by hand with a hemp knife, similar to a long-handled sickle. Plants are cut 2-3 cm above the ground and spread on the ground to dry. In some areas, the entire plants are pulled up and laid out to dry. Hand cutting, one man can cut about one-fifth hectare per day. Sometimes specially designed harvesters with a tractor are able to harvest four hectares a day. In many areas several varieties of hemp are grown so as to spread out the harvest, one maturing in late July and used later for seed crop in September, a second crop maturing in mid August, and a third maturing near end of August. Fiber is extracted from the stems of hemp by retting by methods similar to those used for other fiber plants. Sometimes the stems are dried before they are retted. After plants have air-dried for 4-6 days, the root and flower ends are cut off and the remaining portions, with branches and leaves taken or beaten off, are made into small bundles. For retting, 15-20 of these smaller bundles are made into larger bundles. In other areas stalks are not dried before retting, green stems, after roots and flower ends have been cut off, are made into bundles, and retted immediately. Hemp can be water retted, dew retted, or snow retted, according to the climatic conditions. The retted hemp stalks consist of fiber in the outer rind and a woody interior portion. Fiber is separated from the stalk by a breaking process. Stalks are dried after retting and the woody shive is broken into short pieces called hurds. Eventually the fibers are separated from the interior woody pieces by scutching by passing the bundles through a number of fluted rollers and then past large revolving drums with projecting bars which remove any remaining pieces of wood. Machines are able to handle 3-3.5 MT dried straw every hour, producing 0.4-0.5 MT of cleaned fiber.
Yields and Economics
Yields of hemp per hectare depend on climatic conditions, variety grown, soil and nutrition, and spacing of plants in the field. Weight of dried stems per hectare is usually between 4.5 to 7.5 T, with a yield of fiber about 25% of the dried stalks. Usually the taller the plant, the longer will be the fiber with a greater yield per plant. In some areas fiber yields of 850- 1,700 kg/ha compared to 1,300-1,700 kg/ha seed and 30 kg ganja. The U.S.S.R. is the largest producer of hemp in the world, producing about 33% of hemp fiber, annually 105,000 MT compared to the world production of 255,000 MT (excepting China). France and West Germany are the chief importers, Italy and Yugoslavia exporters. Chile, China, Japan and Peru also produce hemp. Narcotic production is usually clandestine, but there is legal marijuana production in India. India is the main producer and exporter of oil from the seed.
In India, plants remaining in the field after harvesting for fiber are allowed to set seed. They are cut after the fruits are ripened and dried and threshed for seed collection. Grown solely for seeds, an average crop yields 1.3 to 1.6 MT/ha seed. The world low production yield was 288 kg/ha in Democratic People’s Republic of Korea, the international production yield was 613 kg/ha, and the world high production yield was 3,842 kg/ha in People’s Republic of China.
Among diseases of Cannibis are: Botryosphaeria marconii (stem canker, wilt), Botrytis cinerea (gray mold), Cylindrosporium sp. (leaf spot), Fusarium sp. (canker, stem rot), Gibberella saubinetii (stem rot), Hypomyces cancri (?root rot), Macrophominia phaseoli, Phomopsis cannabina, Phymatotrichum omivorum (root rot), Sclerotinia sclerotiorum (stem rot, wilt), Sclerotium rolfsii (southern blight), Septoria cannabis (leaf spot). Nematodes include: Ditylenchus dipsaci, Heterodera humuli, Longidorus maximus, Meloidogyne hapla, M. incognita, M. incognita acrita, M. spp., and Pratylenchus coffeae (Golden, p.c., 1984). Occasionally Orobanche ramosa is paratitic on the roots.