Weed Seedlings Care Guide

Having a healthy marijuana crop depends on the plants’ care in each life cycle and from the first stages, when they are known as weed seedlings. To know more about what weed seedlings are and how to take care of them, you’ll find all the necessary information below.

What are weed seedlings?

‘Weed seedlings’ is how marijuana plants are called during their first stage of the life cycle, from germination when the plant pops through soil. This phase lasts about one and two weeks and it ends when the plants grow their first true leaves.

When germination is successfully completed, the seed coat breaks and the first shoot comes out with the first marijuana leaves, which are called cotyledons, and the roots start growing downwards.

The first pair of leaves marks the beginning of the weed seedlings’ life. However, these are fake leaves and not the ones that the marijuana plant will show as they provide energy for the plant to be created and take its first steps. Keeping your plants healthy during the weed seedling stage will guarantee an optimal vegetative growth.

Weed seedlings care step by step

In regards to providing the necessary care for our plants, we must take into account some different steps:

Choosing the genetic and the right substrate

When selecting cannabis seeds, we must choose the most appropriate ones for each cultivation method. This choice will be made based on the grower’s experience and skill, but also on the budget, the desired effects and flavors.

For the growing medium, it is recommended to use light, airy and slightly acidic soil with a pH between 6.3 and 6.5. It would be wise to mix between 20% and 50% of white perlite into the soil.

Choosing the pots

The chosen seeds will have a particular treatment depending on if they are feminized weed seedlings or autoflowering ones. Thus, if you are growing auto seeds, as they have a shorter life cycle, it is recommended to plant them to never be transplanted in order to not to cause unnecessary stress. Growers normally use between 5L and 15L pots for autoflowering seeds.

For feminized seeds, marijuana plants must be transplanted before the weed seedlings reach the pot size, as soon as they’ve grown several true leaves whose extension completely covers the flowerpot. In many cases, 12L pots are used taking into account the following features:

• Drainage holes: flowerpots should have a good drainage system to prevent the roots from rotting or pathogenic fungi growth.

• Ventilation: roots air exchange with the environment takes place in the pots.

• Pot size: it should be appropriate. If the pot is too big, the risk of overwatering the plant is increased.

Appropriate germination methods

Four things are needed to germinate marijuana seeds: warmth, humidity, darkness, and time. Nowadays, there are some methods like:

• The paper towel method in which you place the seeds carefully in moistened paper towel pieces and place them in a plastic container. Then, set the container anywhere warm but dark and put a half-open cover to allow fresh air exchange.

• The glass of water method consists of placing seeds in a glass with water and putting them in a tent at 20-25ºC (68-77ºF) for a couple of days. When the seeds start showing their first white taproots, they will be ready for planting. Place the root side down approximately 1 cm (0.39 in) deep into the ground.

Factors to be taken into account when growing cannabis

Here are a few tips to give you some help while growing cannabis:

• Keep your plants with optimal temperature: 22-25ºC (72-77ºF).

• Humidity levels: must be around 75 %. It is recommended to gently spray your plant seeds with water when they are dry.

• The amount of light they receive.

To control the warmth, humidity and the amount of light, we must:

Know which nutrients do weed seedlings need

Even if plants absorb nutrients themselves from sunlight and water, we can add some extra nutrients to the water without overfertilizing them. We recommend using root biostimulants for this weed seedlings growing stage. Also, we must have a good control of both pH and EC levels to ensure a healthy growth.

Provide the right amount of light

As weed seedlings don’t need a great amount of light, we can use a cheap CFL light bulb for the first few weeks. If you are using HPS lamps, make sure to keep them away from your seeds to keep them with the optimal temperature. In case you are leaving them in the sun, do it early in the morning or in the last hour of sun: don’t leave them exposed for too long.

Control the watering

Water is vital for the plant’s growth, but in this particular stage, they need higher ambient humidity levels, more than 75%. You can increase these levels by spraying them always without being exposed to direct light late in the evening or early in the morning. Also, we must remember going through periods of moisture and drought.

Once the weed seedlings have grown at least four true leaves or the roots start to tangle, it’s time to transplant them into another pot. If you follow all these tips, your plants will have a vigorous and healthy growth.