Whether you want to grow marijuana commercially for profit, or grow some buds for recreation or medical marijuana to keep you healthy, setting up and using a planting room has many advantages. Unlike growing cannabis outdoors, growing cannabis indoors allows you to control all the key conditions that affect its growth, such as temperature, light, nutrition, and water. In addition, growing weeds indoors can keep them away from destructive four-legged pests, such as rabbits and deer, which may want your crop.

The following detail description are show your the conditions which it need for cannabis cultivation, hope it’s useful for you.

(1) Temperature

Cannabis has different requirements for temperature depending on the type of hemp. Generally, from sowing to process maturity, the accumulated temperature greater than or equal to 0°C is 1900-2000°C, and when the seeds are mature, accumulated temperature is required. 2700-3000℃; for early-maturing varieties, the accumulated temperature of 1600-1700℃ can reach process maturity. Cannabis seeds can germinate when the soil temperature is above 1℃, but the seedlings should emerge neatly.

Generally, it is better to sown when the soil temperature is above 8-10℃. The optimum temperature for the germination of hemp seeds is 25-35℃, and the highest temperature does not exceed 45℃. If the temperature is high, the germination will be fast and uniform.

Cannabis seedlings can withstand a short-term low temperature of -5, but it will seriously affect its growth process.

Suitable temperature for growth, 10-15℃ for seedling stage; 18-30℃ for rapid growth stage, 19-25℃ is the most suitable; 18-20℃ for flowering to seed maturity, and -1℃ low temperature during flowering period, flower organs are damaged , Below -2℃, the floral organs die, especially the male flowers die.

The seed can withstand low temperatures of 3-5°C and lower temperatures within 10-15 days after germination; at a low temperature of -5°C, its growth will be delayed. However, if sufficient water and nutrients can be supplied, the low temperature in the seedling stage has little effect on subsequent development and yield. After the emergence of cannabis in Shandong’s main hemp-producing area in 1957, it was frozen in a shower, and the growth of hemp was not affected. The northern part of Shanxi has the habit of sending seeds in the winter of the first year.

Winter sowing trials were successful in Heilongjiang and Jilin provinces. All these show that the ability of hemp seedlings to resist low temperature is quite strong. Cannabis is not tolerant to low temperature during the flowering period, and it is easy to die when it encounters minus low temperature during the flowering period, especially the death is extremely high.

During the growth period, the average temperature of day and night has a great influence on the growth of cannabis, especially from budding to the end of flowering, the stems grow the fastest, and the dry matter increases greatly; during this period, the optimal temperature should be kept at 16 (night)-25 ℃ (daytime) or so.

2) Water

Hemp is a high-stalk crop that consumes a lot of water. It consumes 300-500 ml of water per kilogram of dry matter, which is 1.5-2 times more than wheat and oats, and 3 times more than corn.

The water in hemp leaves is depleted. Will increase the content of carotenoids including lutein, so the leaves turns yellow and decreases photosynthetic capacity.

Cannabis is resistant to atmospheric drought but not soil drought, so irrigation is particularly effective. During the whole growth period of cannabis, 50-70 cm of precipitation is need.

During the germination period and the first 6 weeks of growth period, the soil should have enough moisture.

When the soil moisture is 70%-80% of the soil water holding capacity in the field, the growth and development are best, which is beneficial to increase the fiber yield.

Among them, the plants in the budding and flowering period are tall and consume a lot of water, accounting for 50%-55% of the total water consumption during the whole growth period.

In the case of late sowing, hemp grows faster than early sowing, and the water consumed during the main growth period accounts for 80-90% of the total water demand.

Therefore, increasing soil moisture during this period has a significant effect on increasing production. Light rain during seed maturity can increase seed yield; when the stem height is 50-70cm, it is more drought-tolerant, but drought and high temperature will promote early maturity, lower plant height and lower yield.

Excessive rain during the flowering period to the maturity of the male plants can easily cause the hemp stalks to become mildewed and black, and it is also not conducive to the maturation of the female plants’ seeds. Cannabis is not tolerant to water logging during its growth period, and water logging in hemp fields for two days and nights will cause hemp plants to die. Soil moisture not only affects fiber yield, but also has a close relationship with quality, and it also affects the content of cannabidiols.

Cannabis plants are cultivated in a soil moisture of 40%, 60%, and 80% with a total water holding capacity of 40%, 60%, and 80%. Regardless of the radius of the cortex and xylem of male or female plants, the number and diameter of primary fibers, and the yield of stems and seeds, As the soil moisture increases, when the soil moisture is equivalent to 70-80% of the total water holding capacity of the soil, the fiber yield and quality are the highest.

The amount of water required by hemp is related to the nutrient conditions in the soil. In the case of good fertilization, the water demand is 575-985 cubic meters, and in the case of poor fertilization or no fertilization, the water demand increases to 790-1180 cubic meters.

Irrigation significantly increases the water consumption of hemp, but the water consumption coefficient decreases with the increase of hemp fiber production and seed production. Mineral and organic nutrients can effectively increase fiber yield and quality under irrigation conditions.

All these show that irrigation and nutrition are mutually cause and effect and promote each other. There is a lot of rain in the south of the Yangtze River in our country. Unless the weather is particularly dry during the seedling period, irrigation is generally not necessary. But in the north, irrigation is very important.

(3) Nutritional Physiology

Cannabis growth requires the three elements of nitrogen, phosphorus and potassium. Nitrogen is the most, followed by potassium, and phosphorus is the least. For the production of 1 ton of hemp stem per hectare, 15-20 kg of nitrogen, 15-20 kg of K2O, and 4-5 kg ​​of P2O5 are required. The research results of Japan’s Sanyo Agricultural Testing Field show that:

Fresh stems and leaves of hemp contains 0.525% nitrogen, 0.133% phosphorus, and 0.415% potassium; fresh stems contain 0.473% nitrogen, 0.111% phosphorus, and 0.341% potassium; fresh leaves contain 0.858% nitrogen and 0.275 phosphorus %, potassium 0.891%.

When hemp is given sufficient nitrogen, phosphorus, and potassium fertilizers, the fiber formation process in its stem proceeds most intensely.

In the complete fertilizer composition, nitrogen has the greatest effect; when nitrogen is deficient, phosphorus and potassium fertilizers have a weak effect on fiber formation.

Therefore, to improve the fiber formation process, early nitrogen application is very important. Late application of nitrogen has little effect on the formation of primary fibers, but can increase the formation of secondary fibers.

Too much nitrogen will make the fiber thicker, reduce the strength, and cause disease. Many experimental studies have proved that the combined use of nitrogen, phosphorus or nitrogen and potassium has a better effect than single application of nitrogen fertilizer. The combined use of nitrogen, phosphorus and potassium can increase the yield more significantly.

This is because phosphate fertilizer has the effect of improving fiber quality (fiber strength and elasticity) and seed yield. Potassium fertilizer has the effect of improving fiber yield and quality, as well as the oil content of seeds.

Potassium affects fiber quality more than phosphorus, and phosphorus deficiency affects nitrogen absorption. Practice has proved that the combined use of chemical fertilizers and farmhouse organic fertilizers plays an important role in increasing fiber yield and varieties.

(4) Light

Hemp is a light crop. The impact of sunlight on cannabis includes two aspects: one is the total amount of light exposure the cannabis receives during the growth cycle, and the other is the amount of sunlight received every day.

In general, the daily exposure has a greater impact on the dry weight of hemp than the total exposure, but the total exposure has a greater impact on the fiber quality (the strength of the nascent fiber).

During seed reserve or oil cultivation, strong light is conducive to axillary bud germination and inflorescence development of hemp plants, thereby increasing seed yield.

In hemp cultivation, weak light can inhibit the germination of axillary buds and reduce the growth of branches into the top, which is conducive to improve fiber yield and quality. The sunlight is sufficient, the above ground and underground parts grow well, and the dry weight and yield increase. But the sunlight is too strong, the fiber development is slow, and it is hard. Therefore, in terms of fiber quality, it is better to use cloudy or cloudy weather with weak light.

Hemp is a short-day crop. Shortening the sunshine can promote flowering, but the plant is short and the fiber yield is low; extending the sunshine can delay the flowering, and the extended sunshine can delay the flowering.

Due to the prolonged vegetative growth period, the plant grows taller and the fiber yield is high.

There are also varieties that bloom under long-day conditions.

Sunlight conditions affect the morphology and biological characteristics of cannabis, shortening the sun can promote the completion of the light phase, and a longer period of short day light makes the plant short;

If the light conditions are suddenly change during the light phase, the plant will undergo a morphological change and make it normal.

The development process of the American “Kentucky” marijuana variety, when one of the two collateral branches of a 3-5 week old plant is treating with 8 hours of short-day, the early flowering is limited to the treated collateral branch.

This shows that the passage of cannabis stage development is limit to the apical bud. When cannabis is subject to short-day treatment at different ages, older plants require fewer short-day days to induce flowering than younger plants, and female plants are more sensitive to short-day sunlight.

During the dark period of cannabis short-day treatment, spraying 15-30 micrograms of thiouracil can partially eliminate the effect of short-day treatment.

Light conditions have such a significant impact on the growth and development of hemp, so in production, the method of southern hemp and northern planting is often use to extend the vegetative growth period to increase fiber yield;

In breeding work, self-crossing or controlling the flowering period for hybridization Use short-day treatment; it can produce several generations of seeds a year, or make two varieties bloom at the same time. This shows that it is of great significance to use the different characteristics of hemp varieties in response to light to obtain high yields.

High-latitude hemp varieties planted in low-latitude areas may bloom earlier and reduce fiber production.