Growing Medicinal Cannabis in Soil

In this article we are going to explain an easy way to grow medical cannabis outdoors using plastic containers or Smartpots, organic fertilizers, and autoflowering strains to encourage a strong root development for bigger plants and more abundant harvests.

Equipment used for the crop of cannabis plants

  • 1x Smart Pot or plastic container 11L-18L
  • Soil – The brand of your preference
  • Root stimulant – Roots XL - Complete Hydroponics
  • Plant stimulant – CompleZym by Complete Hydroponics
  • Growth fertilizer – Coco A&B or Tierra A&B by Complete Hydroponics
  • Bloom fertilizer – Pk 13-14 / B+ / Density by Complete Hydroponics
  • Bloom booster – Boost / Bud Blaster by Complete Hydroponics
  • Your best autoflowering Cannabis Strain seeds

When growing autoflowering strains (autoflowering cannabis seeds are the ones that automatically switch from the vegetative phase to the flowering phase as time goes by) it’s not recommended to transplant given their relatively short life-span and the resulting delay in development that this would cause. To prevent any stress on your plants and ensure a rapid growth, it is recommended to plant directly in the final pot. Once we have made the shopping list and we have in hand all the necessary products, we are ready to begin growing.

10 important tips:

  1. Always try to grow from seeds, not from clones
  2. Use high quality feminized seeds
  3. Use a good soil or growing media like Complete Hydroponics Coco Coir
  4. Do not over fertilize (common mistake)
  5. Germinate with easy start
  6. Please check your water pH  
  7. Do not over-water (Common mistake)
  8. Make sure to have a good growing environment (light, temperature, humidity)
  9. Harvest in the right time
  10. Cure properly for better taste

Germination and growth period

First Week

To germinate the seeds that will be planted in the smartpot of 18l we recommend the paper towel method which is putting the seeds between two dishes. After a week, all of them should be sprouted and developing without problem. Then, when you are sure your plants are growing well, it’s time for a weekly application of Roots XL to facilitate the development of the roots.

After 2 weeks of growth

After two weeks of growth you should see your plants nicely developed, showing some internodes and a healthy foliage. 

                               "A good fertilizers will help your plants to look beautiful and healthy"      


3rd Week

At this point, after the third week, you should notice that your plants start to expand, it’s a good time to apply the fertilizers. It is recommended the use the flowering nutrient from Complete Hydroponics in conjunction with the plant stimulant of the same brand.

When you notice that the plant had stopped growing upwards, then you should stop the application of the Roots XL.

                                    "When Plants stop growing upwards, now it's time to flower!"


Flowering cannabis plants

1st - 2nd Week

In the first and second week of flowering you should observe how the first white stigmas are sprouting from the bud sites. These are located at the top of the plant, but they also should be growing more and more on the secondary branches.

At this stage, the plant will be growing in terms of length and horizontal expansions depending of the plant (sativa, indicia, or hybrid).

3rd week

Now, from the third week forward, the flowering process is expected to kick in and the plant will start to thickening the buds, and you should see sprout all over the plant.

                                                       "Your plants will tell you that it's ready to flower Big-time!"


Maximizing weight production

3rd – 4th week

In an attempt to maximize the production weight, we suggest to try a PK-13/14 from Complete Hydroponics during the next 3-4 weeks. Remember always keeping within the maximum recommended dose.

Continue applying the flowering nutrient and growth stimulants 2-3 times a week, always monitoring the health and condition of the plants to avoid excesses or deficiencies.

                                                         "During the 4th and 5th week, the flowers continued developing"

4th – 5th week

You will see your plants growing slowly but well, spreading throughout the plant. The structure of these plants is similar to a Christmas tree.

6th week

During the 6th week, your plants will be covered with a surprising amount of shiny and fat resin heads.


Final stages of grown plants

This is the last week of applying nutrients. Now, without flushing the roots with excessive watering, start to irrigate with water only, ensuring that the plants feed from and use up their own food reserves stored within the leaves and the buds.

7th week

At the beginning of the 7th week, the buds should start to ripen and began to look very nearly ready, developing and getting fatter and denser every day. This is a good moment to start looking at the development of trychomes, using a magnifying glass if you have them. On closer examination, the flowers should be showing hard and solid buds and should be completely covered with resin droplets.

The color of the flowers are pale green at this stage, and with an unusual silvery-grey tone from the heavy concentration of calyxes.

              "Your plants's flowers should be loaded with terpenes and almost ready to harvest"


At this stage you would be able to observe that the reserves of the soil had become depleted. The plants start their flushing phase, extracting the nutrients from the reserves of the leaves. During this process the foliage gradually turns yellow and then brown until harvest. It’s important during this last phase to avoid a lack of water and not force the plants too much. Around the end of the 7th week and at the beginning of week 8, this effect starts to become obvious.

8th - 9th week

And after passing from week 8 to 9 weeks, the plants must have a very good appearance and almost all the leaves would be yellow and the flowers should be looking tight and beautiful; the trychome heads becomes milky and their stalks tends to bent slightly, indicating that they are almost finishing its ripening process.

At the beginning of the 9th week, trychome stalks become curved and some of the resin heads begin to show amber shades, indicating that it was the right time to cut the plants. At this point Congratulations!!! You are ready to get your first harvest!