How to grow germinated weed seeds?


The growth phase will start after germinating and planting of your regular, feminized or autoflowering seeds. This is also called the vegetative phase. An exciting period, because your seedlings are still very vulnerable for the first two to three weeks. Growing weed from seed is not that hard, but it’s important to know what you should and should not do.

Do you want to know how you expertly handle the growth process of your cannabis plant so your seedling will grow optimally? Then read this blog about: how to grow germinated weed seeds.

Tips before growing germinated weed seeds

There are no set rules for the growth phase. Everyone grows in its own way. Yet there are a few useful tips:

  • A cannabis plant grows as long as it receives 18 hours of light and 6 hours darkness. As long as this light scheme is maintained, the plant will only grow. Note: this doesn’t apply to autoflowers.
  • The growth phase lasts an average 2 to 8 weeks. This depends on your wishes.
  • Do not provide young plants with nutrients.
  • Check your plant daily so you can spot any problems on time.
  • Provide the plants enough water. Do this manually. An automatic pump system can become clogged.
  • Make sure your plants remain dust-free so they can absorb maximum light. You do this, among other things, by rinsing the plants regularly. However, be careful. Wet leafs can burn through the lamp.
  • Do you want to grow outside? Then find a place where nettles grow. This soil is very suitable for the cultivation of cannabis plants.

How to allow germinated cannabis seeds to grow?

To grow your germinated cannabis seeds you will have to create optimal conditions. You do this by arranging five things directly:

  1. Provide the pots with the germinated seeds access to light
  2. Set a temperature of 20 to 25 degrees Celsius
  3. Make sure your soil has a PH value of 6 to 6.5
  4. Provide a humidity of 60%
  5. Provide ventilation

1. Provide the pots with the germinated seeds access to light

After potting and as soon as the seedlings grow out of the ground they need direct access to bright light. The seedlings for indoor cultivation can easily be placed in an artificially illuminated environment.  However, seedlings for an outdoor cultivation will have to get used to the sunlight before you actually place them outside. Place the pots first in your house on the windowsill and increase the exposure to direct sunlight by an hour or two per day. If outside temperatures permit, seedlings may get used to direct sunlight and outdoor conditions. Starting at about three hours a day, during the sunniest hours. Then an extra hour per day so the cannabis plants can be permanently outside after two weeks.

When the seedlings have produced their second or third set of serrated leaves (the round cotyledons that are initially excluded from the seed), they are usually strong enough to get access to direct sunlight or a grow light. 

Light distance for weed plants

  • When using HID lighting (High Intensity Discharge), keep the seedlings at a distance of at least 50 – 80 cm from the lamp. 
  • With a low-energy light bulb (100 watts or more) you have to keep a distance of about 15 cm between the young seedling and the lamp.
  • When using fluorescent tubes (usually 18-36 watts), seedlings are kept only a few centimeters from the light source.

2. Set a temperature of 20 to 25 degrees Celsius

A cannabis plant grows well at a temperature between 22 – 25 degrees. Make sure that the temperature in your growing environment is constantly at this temperature.

3. Make sure your soil has a PH value of 6 to 6.5

PH is the name for the acidity of the soil. Pay attention: a low PH means an acidic soil while a high PH value means a non-acidic soil. PH 1 is therefore very acidic, PH 7 is neutral and PH 14 is called basic.

Both during the growth phase and afterwards you will have to maintain a PH value of 6 to 6.5. A PH value which is too high or too low isn’t good for the growth of your cannabis plant and can be fatal. Measuring is knowing. Therefore, ensure a PH meter.

How do you adjust the PH value?

It may be that your soil has a too high or too low PH value. Fortunately, this is easy to solve.

The PH value is too high

Do you have to deal with a too high PH value? For example a PH value of 8? Then your soil is not acidic enough and you must acidify the soil. You can do this simply by dissolving a few drops of vinegar in your water. Note: do this carefully. A few drops are often more than enough to bring the PH value to the desired level.

The PH value is too low

If your soil is too acidic (the PH is lower than 6), you can dissolve a very small amount of soda in your water. Also do this carefully. Too much soda brings your PH out of balance quickly.

4. Provide a humidity of 60%

Young cannabis plants need a high level of humidity for the first 6 weeks. Here, a humidity of 60% is best.

5. Provide ventilation

Cannabis seedlings that grow under lamps always need a light breeze (from a home-garden and kitchen fan is fine). The constant movement strengthens the stem enormously.

> Read our next blog: The stages of a weed plant