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Several factors affecting the growth of indoor cannabis cultivation

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In the United States, more and more people tend to grow hemp. This is not only because of the legalization of hemp cultivation in many areas, hemp cultivation also brings economic benefits and sense of accomplishment to growers. Among them, indoor planting has also become a popular trend. Simple equipment, small planting environment, and economic benefits that cannot be underestimated are the reasons for its popularity. Here is a brief introduction to the major factors that need to be understood when growing cannabis indoors.

1. Preliminary preparation



Indoor cannabis cultivation requires planting lights to supplement light. In different periods, the temperature requirements for cannabis growth are different. Cannabis seeds can germinate when the soil temperature is above 1°C, but the seedlings should emerge neatly. Generally, the soil temperature is 8-10°C. The most suitable temperature for marijuana planting and germination is 25-35 degrees Celsius, and the highest temperature does not exceed 45 degrees Celsius. If the temperature is high, the germination will be fast and uniform.

Cannabis seedling stage can tolerate short-term low temperature of -5℃, but it will seriously affect its growth process. Adapt to the growth temperature, the seedling stage is 10-15℃, the rapid growth period is 18-30℃, and 19-25℃ is the most suitable. It is 18-20℃ from flowering to seed maturity. In the flowering period, when the flower is -1℃, the flower organs will be damaged. If the temperature is below -2℃, the floral organs will die, especially the male flowers will die.

Seeds can tolerate a low temperature of 3-5°C or lower within 10-15 days after germination. At a low temperature of -5°C, growth will be delayed. Cannabis is intolerant to low temperatures during flowering.

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 fastest, and the dry matter increases greatly. During this period, the optimal temperature should be kept at 16 (night)-25 (During the day) Around.



Cannabis cultivation needs to choose a suitable size and good air permeability container according to the amount of cannabis roots in different time periods. Generally, you can choose textile flower pots or plastic flower pots with drainage holes at the bottom. This is conducive to the respiration of the soil, the reasonable control of water and nutrients. There is a possibility that it needs to be replaced in different periods. This process is not simple or even easy to damage the cannabis plant, but it is still necessary.

Soil and fertilizer

The liquid fertilization schedule depends on the type of cultivation medium selected. Whether it is using hydroponics or soil cultivation, in the entire process of cannabis planting, you need to fertilize at least a few times until it starts to bloom. It is also important to know whether it is suitable or not to fertilize. In the last two weeks before receiving the goods, only water the plants to help them remove the nutrients from the buds. This practice will improve the quality of the smoke when the marijuana is lit, and this practice is also known as "flushing." The entire fertilization process requires careful monitoring and recording. Many growers start with a nutrient solution that is lower than the recommended dose and gradually increase it until the plant knows the best response. Most hemp growers will choose organic soil. Purchase disinfected organic soil through formal channels. If you choose ordinary outdoor soil, you need to disinfect it yourself to avoid pests and diseases.

2. Planting process


The germination of hemp seeds requires the right temperature and humidity. Three common germination methods include direct soil germination, hydroponic germination and cotton substrate germination. For hydroponic germination, the seeds need to be soaked in water for a week, the temperature is controlled at 18°C, and the replacement is performed once every two days, using clean tap water. If you use cotton pads or common rock wool on the market to germinate, you need to put it in the soil when the seed germinates 3-5mm. It is worth noting that this method requires soaking the rock wool, adding an appropriate amount of fertilizer, and reducing the soil. The pH value. The other two methods above are not required.

Humidity and temperature

In the process of marijuana planting, it should be noted that the requirements for temperature and humidity for plant growth during the day and night are different. The "daytime" of indoor planting is mainly the period of supplementary light. Generally, 20-25°C is required for "daytime" and 5-10°C at night. Controlling humidity is absolutely critical to maintaining plant growth plans and obtaining optimal yields. If the humidity is too low during the vegetative growth phase, the plants will be stunted, and in order to restore their health, you may lose weeks of production time. But if the humidity is too high, you are at risk of disease outbreaks, including the notorious bud rot.

Although humidity is very important for the soil where hemp is grown, growers should mainly keep the plant's surroundings relatively dry and encourage resin coverage, but it is not recommended that the indoor temperature be too high and the humidity should be above 70%. If the humidity is too high, it will easily cause the cannabis leaves to widen, which is not a good thing for growers.



The main function of ventilation is to prevent mold, fungus and other possible problems, and to ensure that the cannabis leaves breathe smoothly. Especially during the flowering period of the plant, insufficient ventilation can easily lead to moldy marijuana buds.


Hemp is a high-stem crop and consumes a lot of water. It needs to consume 300-500 ml of water for every kilogram of dry matter. Water loss in cannabis leaves will increase the carotenoid content including your lutein, so the leaves will turn yellow and their light and capacity will decrease. Cannabis is resistant to atmospheric drought but not soil drought, so irrigation is particularly effective. During the full growth period of hemp, 50-70cm of precipitation is required. During the germination period and the first 6 weeks of growth, the soil must have sufficient moisture. The soil moisture during the rapid growth period should be high. The soil moisture is 70% of the soil field water holding capacity. %-80%, the growth and development is the best, which is beneficial to increase the fiber yield. The amount of water required by hemp is related to the nutrient conditions in the soil. In the case of good fertilization, the water requirement is 575-985 cubic meters, and under the condition 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.

Flowering care

Cannabis blooms after the plant has gained enough time to grow and develop. It takes 12 hours of strong light and another 12 hours of dark night (it must be absolute dark) to trigger the flowering of cannabis, which usually lasts 8-10 weeks until the harvest period.



Pruning of hemp is not necessary. The prerequisite for pruning is that you have found that the plants are growing vertically. How to trim it? Cut off the intersection of the two branches at the top of the plant, preferably with a sharp blade. This pruning method helps to speed up the numerical growth near the bottom of the plant, but it also requires the operator to have certain skills and experience.


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