Rookie Guide: 3 Steps to Master the Seedling Stage
Mastering the delicate seedling stage is crucial to grow strong and healthy cannabis plants. Read this blog for further information on how to cultivate cannabis from seed to seedling.
1. CONTAINER AND GROWING MEDIUM
Before germinating our cannabis seeds, we make up our mind about containers and soil, assuming most rookies prefer soil due to simplicity. At this point, we already need to differentiate between autoflowering - and feminized/regular seeds.
A. POTS FOR AUTOFLOWERING SEEDS
Growers of autoflowering varieties will get best results when they plant the seed directly into the final pot, and need to pay very close attention to seedlings for the first three weeks. Mistakes in the vegetation period of autoflowering strains have fatal consequences, meaning low yields. Depending on the strain and growing method, pot sizes ranging from 5-15 liter can be used. The size of the pot will have an influence on the size of your plants, on yields, and on the frequency you water your plants. Tip: Airpots allow more oxygen to get to the root system and will boost vitality and final yields.
B. POTS FOR FEMINIZED SEEDS
Feminized- and regular cannabis varieties give growers the possibility do decide when the vegetation period ends, and the flowering period starts. This is why transplanting “feminized” seedlings is not such a big concern, in contrast to autoflowering strains. When a few days are lost due to stress recovery of the plant, growers simply increase the time-span of the vegetation period and compensates the loss of growth. Internet forums and grow reports can help to get you an idea what works best in terms of pot size(s) matching your setup.
C. GROWING MEDIUM
High quality organic soil that is “light” when it comes to pre-added nutrition works best.
2. GERMINATION TECHNIQUES
There are basically two different techniques that are commonly used to germinate cannabis seeds.
A. THE WET PAPER TOWEL METHOD
Carefully place your cannabis seeds between wet paper towels and place them in a sealable plastic container. Aim for high humidity levels inside the container, temperatures between 20-25 °C, and moist, but not overly wet paper towels. Check moisture and humidity levels regularly. Don’t completely close the container and allow some air exchange. This happens at a dark place.
B. GERMINATING SEEDS IN WATER
Simply drop your seeds into a glass of drinking water and wait 24-48 hours until seeds have cracked. Wait until you see the first few millimeters of the root, and make sure water temperatures are between 20-25 °C. Place your cup somewhere light doesn’t reach it.
3. ENVIRONMENT: LIGHT, HUMIDITY AND WATERING
After seeds have germinated, it’s time to plant them into the pots. Plant the seeds just 3-5 millimeters below the surface of the earth, ideally with the tiny root facing downwards. This can help to avoid time-loss and seeds don’t have to figure out how gravity works.
It’s not necessary to use your powerful HPS or LED the first 10-14 days. CFL’s with a blue light spectrum (daylight/coolwhite) will get you very good results. Either built your own light fixture using T5/T8 sockets or buy 23-30W CFL’s with the standard European E27 lamp socket. Compare different bulbs and choose the ones with highest lumen output.
Aim for humidity levels of approximately 70%. Small propagators can be an option if you start in very small containers but autoflowering growers planting in final pots need to monitor, and eventually raise, the humidity inside the grow room.
This is by far the most important part when growing seedlings, and cannabis in general. Don’t overwater your plants due to overly high levels of affection for your cannabis plant! The root system has no motivation to grow if it’s constantly flooded with water. You need to find your individual rhythm or cycle between wet and dry. This will come over time and your seedlings will thrive if you pay close attention to watering. Remember, less is sometimes more!