I personally go straight to soil. Heres an article. Take it for what its worth. It was written by someone at Mandala seeds. And i have had retarted plant growth.. Here it is.
Planting Seeds and Germination
Mandala Seeds places great emphasis on the quality of the seed stock and we guarantee that the seeds from all products are fresh and viable. Seeds harvested from each mother plant are checked for optimal germination rates before they are approved for sale! In large tests (1000 or more) our seeds achieve a germination rate of 99,6%. Our seed stock is refreshed every 6-12 months! Therefore seed vendors and customers can be certain to purchase and store viable seeds at any time.
Due to our high standard of pollination, attentive grow methods, and the dedicated hand selection of seed stock for sales, our seeds are always perfectly matured and can be quite large. They also possess a particularly intact and hard seed hull. The robust genetics of our cannabis varieties, and our innovative Deluxe seed production methods, leads to the development of healthy and strong seeds with a good resistance against environmental factors. Due to the firm seed hull and large size some of our seeds may require a slightly longer germination time. Most seeds sprout in record time and others take a bit longer. Once the seedling grows through the substrate it will develop quickly and vigorously regardless of the germination time.
For an optimal germination result the seeds should be planted DIRECTLY into the substrate. We clearly advise against using pre-germination methods or soaking. Please do not place the seeds into a glass of water or in moist paper tissues.
This does not mean that pre-soaking should never be used with seeds from other sources, or that we criticize growers who prefer this method. We are aware that some breeders recommend it for their products. But to prevent complications and achieve the consistent level of high germination rates that you should be getting from your Mandala seeds please trust our advice and follow our guidelines.
Please take note that customers who soak their Mandala seeds in water or wet paper tissue do so at their own risk. We are not accountable for any failure in germination or complications caused by this method.
Fresh and healthy seeds prefer a nurturing and airy substrate to germinate in – just as mother nature has meant it to be. Cannabis is a plant species originating from semi-arid and temperate biotopes and the vast majority of modern cannabis hybrids contain a substantial percentage of these genetics. Cannabis seeds are not adapted to swampy wetlands, but they are suited for germinating in well drained soil/substrate. In nature they rot if they fall into a puddle of water...and there are no paper tissues lying around either. Taking into account these botanical facts, it is quite logical that by creating germination conditions that are similar to those of the natural habitat you can expect the best results.
What happens if one uses pre-germination methods?
1. Soaking seeds in water/wet paper towels is a method which can be used for old seeds (3+ years) that are drying up and losing germination power; and for pure land race equatorial strains such as from Africa. Both factors do not apply to our seeds.*Fresh seeds have a healthy embryo whose cells are filled with water. But excess water causes the cells to bloat, depletes oxygen and leads to the tissue rotting away before the seed embryo can germinate. Old seeds have lost water in the cell tissue, the embryo starts to shrivel, which is why germination rates drop the older the seeds are. Therefore, old seeds (ie. 3+ years) can soak up more water before adverse conditions cause them to rot. This is one of the main reasons why various seed stock reacts differently to pre-germination methods. Some growers make the mistake of soaking our seeds in water for up to 1-2 days because it may have worked in the past with other seeds. This does not mean, however, that this method can be used for all seeds. In fact, old stock or equatorial cannabis seeds should only be soaked in water for a few hours at the most. Always consult the web site of a seed bank for specific advice and instructions on how to germinate their seeds.
It is in a growers best interest to choose a germination method with the lowest risk of complications. Because we want customers to have the highest success rate possible we recommend the most convenient and safest method. This does not mean it is the only option. We simply believe it carries the lowest risk for germinating fresh seeds. Planting seeds directly in the substrate is also the most plant friendly method for any type of seed stock. The reasons are explained below in paragraph 2 & 3.
2. Placing healthy & fresh seeds in water/wet tissue can lead to the development of fungi or bacteria on the seed hull. Lack of oxygen and contaminating substances in the water/wet tissue promote fungal growth which can be transported to the substrate later on. Often the seed simply rots away if left for too long in a glass of water, or wrapped up in wet tissue.
3. Once the seed sprouts in a glass of water or paper tissue it already has the taproot growing out of the cracked seed hull. While transplanting the germinated seed it is very difficult, indeed impossible, to prevent damage to the delicate taproot. Many sprouted seedlings handled in this way show retarded development, or even simply fail to appear out of the substrate after transplantation. Handling seedlings this way can impair the health & vigour of the plant for the duration of it’s life cycle - especially if other disturbing factors occur during the early stages of growth.
Professional horticulturists rarely use pre-germination methods to actually grow out the seedlings because of the shock suffered from transplanting them. For example, we use the paper tissue method only as a quick test for germination rates of aged seed stock from our genetic repository. This allows us to see beforehand how many seeds we have to put in soil to get the amount of plants we require for breeding projects.
Germinating cannabis seeds is not difficult. All you need is some basic information on what is important and everything should work out fine.
Here are our tips for germination:
Please use high quality soil or rockwool starter cubes for germinating seeds. Do not use jiffy’s/peat pellets/rooter plugs: the acidic pH of pure peat can inhibit germination of cannabis seeds.
SOIL: take 8-10 cm/3-4” (diameter) pots and fill them with quality potting soil. Press the soil slightly down and make a 1,5 cm/0,6” deep hole with a pencil or finger. Place the seed in a horizontal position in the hole*(this is the easiest method). Fill the hole and gently tap down the soil. Use chlorine free water (preferably good mineral water without gas) with a pH of 6-6.5 to water the pots. The soil should be uniformly moist but not soggy or waterlogged. Use a spoon to water if necessary. Put the pots at a warm location. Temperatures at 25°C/75°F or higher accelerate germination. Take care that the soil does not dry out and that the pots don’t stand in the cold (ie. at or under 21°C/70°F). Misting the soil surface with water spray is not particularly effective. Rather, you should water the pots properly if the soil surface dries up.
ROCKWOOL: immerse the rockwool cubes in luke-warm water with a pH of 5.6-5.8 until the rockwool is evenly wet. Overnight soaking is not required for starter cubes. Let the water drip off...squeeze lightly to assist. Place the seed in a horizontal position into the hole (this is the easiest method). The taproot can grow downwards assisted by gravity. Alternatively, you can also place the seed into the hole vertically with the rounded end facing up (cannabis seeds sprout by opening the shell at the pointy end where the taproot grows out). Cover the hole with a small piece of rockwool. Choose a fluffy piece of rockwool...you don’t want to tightly plug the hole because the seedling has to grow out with ease. Water the rockwool cubes with a weak nutrient solution of 10-15% of the recommended dosage (or EC 0,6) and pH 5.6-5.8. You can also germinate using pure water. Put the rockwool cubes at a warm location. Temperatures at 25°C/75°F or higher accelerate germination. Take care that the rockwool cubes do not dry out or stand in the cold (ie. at or under 21°C/70°F). They should also not sit in water. Usually the cubes require to be moistened with pH adjusted water every 1-2 days. Use chlorine free water such as mineral water. Within 3-4 days the seedlings should appear out of the cubes. Hot tip: to prevent the cubes from sitting in water put some perlite at the bottom of the tray for drainage.
IMPORTANT:
* Don’t cover pots with plastic wrap, don’t use a humidity dome, or place pots/rockwool cubes in a propagator that’s completely covered! This prevents fresh air exchange, raises humidity to excess levels, and easily facilitates the spread of fungus. The seeds then rot before they can germinate. Excess humidity coupled with lack of oxygen is the #1 cause for poor germination results!
If you germinate your seeds at room temperature, and have properly watered the substrate, there is no need to be concerned that it will dry out overnight. Only the substrate requires sufficient water for the seeds to germinate - the outside humidity can and should be be low to moderate (ie. max. 55%). Low humidity in the room does not interfere with germination or healthy seedling growth. Remember: cannabis is not an orchid! Fungal spores are everywhere: in the air, in substrates, ... and they await the conditions to spread and attack organic substances such as seeds or the roots. Common fungal infections are pythium and fusarium. Young seedlings are also prone to such infections because their cell tissue is very soft. Over watering and/or high humidity trigger such diseases like “damping off” which quickly kills seedlings.
* Avoid heating mats. A dysfunctional heating mat, or a mistake in the temperature control, can easily boil the seeds or dry up the substrate and shrivel the feshly emerging seedling. Your pots/rockwool cubes should be placed in a space with ambient room temperature (ie. 24-26°C/75-78°F). In the winter use a small electric or gas heater to warm up your grow space. You can also switch on the HPS lamp and put the pots at a close distance underneath.
Seedling care:
Within 3-5 days the seedlings should appear out of the soil.
As soon as the first pair of leaves grow on the seedlings transplant them into 14-16 cm/5,5-6,5” pots, so that they have sufficient space for their root development and nutrients. You can also choose larger pots if you are confident that you won’t over water. Seedlings require sufficient light (this applies to the strength and length of daylight or artificial light) and fresh air to grow. Switch on your lamp(s) as soon as the first seedlings appear at the latest.
Do not fertilize in the first weeks of growth on soil!*This is the #1 cause for sick plants. Rather, transplant into high quality soil and bigger containers as the plants grow larger.
Recommendations:
Take advantage of our low prices and plant an extra 1-2 seeds if you don't use the whole pack of 10 seeds. Although we, and the plants, do everything in our power to produce 100% viable seeds please remember this is a biological product. Therefore, even if a seed looks perfect from the outside, it can't be prevented that a minor % of seeds does not germinate, or that the seedling is not completely healthy. That's why it's a good idea to have an extra seed sprouting as a back-up and then you can always select the best seedlings for your grow.
Keep your fingers from those ferts and potions. Yes, it happens again and again: growers feeding their seedlings on soil with mineral or biological fertilizers & rooting products, spraying them with homemade teas, or killing them not so softly with harsh biological pesticides. Seedlings are baby plants with delicate young leaves and roots. Let's put it this way: you don't feed a T-bone steak to a baby. Seedlings require 3 weeks to develop into stouter and tougher plants. During this phase of development a good soil mix and decent container size provides all the nutrients they require.
Don't forget to check your water pH with every watering and use cheap vinegar to adjust it downwards instead of mineral salts (to prevent salt build-up).
Mandala strains are unique in their high level vigor and fast growth. For optimal plant growth you don't require to perk them up with root stimulators. The Mandala genetics already come with an inbuilt turbo boost. Root stimulators can in some cases be counterproductive. To support the vigorous growth of our strains you should buy quality soil and choose/adjust container sizes according to the size of the plants. Rootbound plants quickly develop nitrogen deficiency and other deficiencies. “Rootbound” is a condition which exists when a potted has outgrown its container. The roots become entangled and matted together, and the growth of the plant becomes stunted.
