You can use a humidity dome/mini-greenhouse as a tray for germination but you must keep the lid half-way open or completely seperate to ensure fresh air exchange and humidity levels below 50%.
Some or all seedlings fell over and died
Possible causes for:
All our seeds are pre-tested. and we mean ALL seeds from all strains. Every single seeded mother plant has been tested for perfect germination prior to sale. This ensures that there are no "bad batches".
Poor germination results can only be the result of negative outside influences after purchasing the seeds and are beyond our control. This does not necessarily mean that the grower is at "fault". Even the most experienced grower can run into unforeseen problems such as fungus infected soil, a technical malfunction on an EC meter, etc. Often growers buy the wrong soil because it is recommended by the manufacturer or retail store (consult our Soil Guide for more info).
b) Dark seeds indicate fungal attack. A whitish substance is visible fungal mycelia. Fungus spreads under cold, wet, & anaerobic conditions. Several combinations of factors can lead to seeds rotting: poor soil quality (infected, bad pH, or high EC), pre-soaking seeds in water, substrate is too wet, substrate is in a cold environment, and/or excessive high humidity caused fungal growth in substrate (due to humidity dome/propagator, pots covered with plastic, poor ventilation).
This is another problem caused by a fungal infection. In this case, the reason for the fungus can be infected soil, high humidity or a waterlogged substrate. The fungus infiltrated and damaged the stem of the seedling, causing it to wither and ultimately to collapse.
GROW TIP: When your seedling has already grown long and leggy because of not enough light you want to support it with a stick so it can regain its strength once you moved it closer to the light.
Tap water with its often high levels of chlorine, fluoride and salts can be another reason for a failed germination. The minerals and salts can stunt the growth of the very sensitive seedling. If you really need to use tap water, fill a bucket with hot water and have it sit outside for a day so the chlorine can evaporate. Even better, use bottled water for germination.
Problem: Seedlings Grow Weak And Stretched
If your seeds won’t germinate, the first thing that you should do to find the cause is to look at the seeds. Seeds that won’t germinate can have changed their colour, most of the time they may have gotten noticeably darker. There can also be a white coating at the rounded end of the seed. When you crack open the seed you can sometimes notice that the embryo has become soft.
This germination troubleshooting guide highlights some of the most common problems and mistakes made with germination. If you know the cause why the germination of your seeds has failed, this guide can help you prevent this from happening again.
Many cannabis growers are still pre-germinating cannabis seeds in a glass of water or with the “paper towel method”. In the first case they would pre-soak the seeds in water for some days and in the second they put seeds between wet paper towel sheets and have them germinate there.
The drawback with these pre-germination methods is that they are very error-prone. The potential problems from these methods like fungus growth or damage to the sensitive tap roots when moving the seed to a new medium are normally outweighing their supposed benefits. Good quality seeds don’t normally require pre-soaking, whether it’s in water or with wet paper towels so that it is recommended that you don’t use these methods. Have your seeds germinate in their final pot, which helps keep your risk down for a higher chance of germination success.