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Vegetative Stage

what happens in the vegetative stage?

The vegetative stage follows the seedling stage and will take around 3 to 16 weeks (2 to 3 weeks for auto-flowers). This stage is also known as the growth period, it is where the plant really takes off and starts growing rapidly. At the start of this stage, cannabis plants should be transported into a larger container, to allow the root system to fully develop.

You should start noticing the difference in the spaces of the nodes (where the stem meets the smaller branches). An indica plant will stay short with dense leaves, whilst a sativa will grow much taller, with less complex leaves and branches.

The vegetative stage ends when the plants starts producing buds, in which it will start the flowering stage. Another way to tell if your plant has finished the vegetative stage is that it will start developing male or female parts (pollen sacs for a male plant and white pistils on a female plant), although these can still be spotted much earlier on. 

watering during the vegetative stage

The bigger the plant gets, the more water it will need, and plants can easily become dehydrated at this stage. Early on in the vegetative stage, while your plant is still young, you should water close to the stem. Once the plant starts to develop, water further out from the stem, so the roots that have reached out wide have the best chance of absorbing as much the water as they can.

You should water when the top inch of the soil or growing medium feels dry and ensure that water can easily drain from the bottom of the pot. A good pot size for home growers is around 20 litres. 

baby marijuana in soil

temperature during the vegetative stage

During the vegetative stage, cannabis plants will do well in temperatures around 20 to 30 degrees Celsius. If growing outdoors in a very hot climate, growers can put their marijuana plant under a shelter to protect it from the high heat. For indoor growers, the temperature is easier to control with lighting, fans, thermometers, and humidifiers/ dehumidifiers. Cannabis plants do not like low humidity so the humidity level should not drop below 40% at this stage. Keep the humidity high during the first two weeks of vegetation.

When checking the temperature of indoor plants, do this under the light, right at the top of the plant. You can try putting your hand just under the light to test the temperature. If it gets too hot to hold it there after 10 seconds, then it is too hot. Either turn down the heat or use a fan to disperse cooler air to the plant. 

providing good lighting

Lighting is a crucial element when growing marijuana and your plant will need a lot of light. In the vegetative stage, photoperiod strains (those that flower when the light cycle changes) will need around 18 to 24 hours of light each day. This is reduced to 12 hours a day at the start of the flowering stage. If you leave the lighting at 18 to 24 hours, the plant will remain in the vegetative stage. The more light the plants gets, the faster it will grow.

For auto-flowers, you will not need to reduce the light- they will start to flower on their own, i.e. automatically. For outdoor growers, your plants should naturally stay in the vegetative stage, until the days get shorter.

You can leave your cannabis plants in the vegetative stage from a few weeks to a several months, depending on how large you want your plant to get. Generally, the bigger the plant, the more buds you will get. Remember that as your plant grows, you must keep up the lighting to cover the whole plant, so the buds will develop well.

4 weeks in the vegetative place is a good place to start, with 18 hours of light each day. If you live in a cooler climate or your plants are kept in a cool room, then you may want to try a 24-hour light cycle, to make sure they are kept warm. 

Female_cannabis_plants_in_the_vegetative_(pre-bloom)_phase
(CC BY-SA 4.0)

which nutrients to provide

Cannabis plants will need higher levels of nitrogen during the vegetative stage, which will assist with the growth of leaves and stems. They will also need good amounts of potassium and magnesium. A nutrient solution that has high nitrogen (N), medium phosphorus (P), and medium/low potassium (K) is ideal. 

training your plants

Training your cannabis plant can optimise the amount of yield/ buds you get. By exposing the leaves that sit below the top canopy, more of the light will reach the rest of the plant, increasing your chances of a higher yield (more buds to develop). There are various techniques in order to train your plant into growing a more optimised way.

Low Stress Training

This is one of the least stressful methods of maximising your yield on your marijuana plant. The process is achieved by bending taller branches over, using a weight or tied down. This can expose more of the plant to the light, producing more rows of buds.

High Stress Training

This process is similar to low stress training in that you are bending back taller branches that may be keeping the buds below in the dark. However, with this method, you will snap the branches holding the buds, just below a new cluster of flowers. This will allow the full bud to have the most light as possible. This method is usually done at the start of the flowering stage and should only be used by experienced growers. If done incorrectly it could damage the plant but if the process is successful, it can produce a great deal more yield.

Topping

‘Topping’ is the process of cutting off the top of the main stem, in order to produce and encourage further growth, and therefore more yield. It will then develop into two more stems. Give the plant a few weeks rest in between each process.

Screen of Green Technique (ScrOG)

The ScrOG method involves placing a netted screen over the top of your plants. The plant will then grow up through the screen, where it can be trained to grow in an even and horizontal way. This technique allows the leaves and branches to be spread out, allowing the buds below to develop as opposed to only the buds at the top of the plant. 

Small_Lowryder

tips

  • Provide good air circulation. Your cannabis plants need CO2 in order to grow, so ensure there is enough fresh air moving through your plants. This can be achieved with a simple fan or air conditioning unit for indoor growers and for outdoors growers a wind shield would be useful to protect the plant from windy environments.
  • Monitor your plants for mould. If you see a white looking powder on your leaves or buds, your plant may have mould (white powdery mildew). This could be due to the humidity being too high or a lack of air circulation and ventilation. If caught early on, this can be resolved.
  • Stretching– If you notice your plant has grow a long tall stem, without many leaves, it could be a sign that it does not have enough light. Either increase the brightness or move your plant closer to the light.
  • Observe your plant. It is important to keep checking your plant for any signs that it is not growing correctly. If you notice signs of pests, or the leaves discolouring, then the quicker you act, the better the chances of recovering your plant.
  • Sexing your plant. During this stage, you will start to notice differences in the spaces between the nodes. If your plant has developed tiny sacs, then good chances are that it is a male plant. You should separate the male plants from the female, to stop them pollenating. Only the female plants will produce the buds you need to turn into marijuana.