Jorge’s Cannabis Encyclopedia: Seed Germination
Cannabis seeds need only water, heat, and air to break dormancy and germinate; they do not need extra hormones, fertilizers, or additives. Seeds sprout without light in a range of temperatures. Strong, viable, properly nurtured seeds germinate in 2 to 7 days. At germination, the outside protective shell of the seed splits, and a tiny, white sprout (radicle) pops out. This sprout is the root, or taproot. Cotyledon, or seed, leaves emerge on a stem from within the shell as they push upward in search of light.
Break dormancy: Put newly harvested seeds in the refrigerator for a week or two to simulate winter. Remove and germinate. Seeds will germinate more uniformly because they all come out of dormancy at the same time.
Timeline for Germinating Most Seeds:
At 36 to 96 hours – Water is absorbed, root tip (radicle) pops through outer shell and is visible.
At 10 to 14 days – First roots and root hairs become visible.
At 21 to 30 days – At least half of seeds are rooted by day 21. Seeds not rooted by day 30 will probably grow slowly.
Once seeds are rooted, cell growth accelerates; stem, foliage, and roots develop quickly. Seedlings develop into full vegetative growth within 4 to 6 weeks of germination.
Seeds are Prompted to Germinate By:
Water: Soaking seeds in water allows moisture to penetrate the protective seed shell within minutes. Once inside, moisture continues to wick in to activate the dominant hormones. In a few days, hormones activate and send enough signals to pro- duce an initial root tip. The white radicle (rootlet) emerges to bring a new plant into the world. Once a seed is moist, it must receive a constant flow of moisture to transport nutrients, hormones, and water so that it can carry on life processes. Some seeds need lots of moisture to wash out the dormancy hormones in the seed coat, and if they do not get enough moisture, they do not germinate. Conversely, too much water deprives the seed of oxygen, reducing its quality or destroying it. If fragile germinated seeds are allowed to suffer moisture stress now, seedling growth will be stunted. Soaking most seeds in water for 12 to 24 hours is all they need to initiate germination. All the nourishment for a seed’s initial growth requirement is pulled from the fleshy cotyledons, or seed leaves. Water seedlings with low-EC (electrical conductivity) household tap water during the first week or two of life. Supple- mental nutrients are unnecessary and if applied in excess can disrupt internal seed chemistry. Some gardeners prefer to germinate seeds using distilled or purified water that contains virtually no dissolved solids.
Temperature: Overall, cannabis seeds germinate in temperatures from 70°F–90°F (21°C–32°C) and grow best at 78°F (26°C). Temperatures below 70°F (21°C) and above 90°F (32°C) impair germination. Low temperatures delay germination. High temperatures upset seed chemistry causing poor germination. Seeds germinate best under the native conditions and temperature ranges where they were grown.
Air & Oxygen: Sow seeds twice as deep as the width of the seed. For example, 0.125-inch (3 mm) seeds should be planted 0.25 inches (6 mm) deep. Adequate oxygen is un- available for seeds planted too deeply, and tender seedlings have insufficient stored energy to drive through deep layers of soil or crusty hard soil when sprouting.
Agricultural Astrology — Planting by the Moon
Ancient Babylonians and Egyptians planted and harvested based on moon phases in relation to geographic location. The premise is that plants grow better when planted during the appropriate moon phase.
Moon phases cause ocean tides to rise and fall. They also affect the rise and fall of moisture in soil and fluids inside plants. The moon phase influence is said to be the same indoors, outdoors, and in greenhouse-grown cannabis.
Cannabis gardeners who plant by the moon report faster-sprouting seeds that grow into vigorous plants. However, scientific evidence is lacking in regard to cannabis and other plants’ relationship with agricultural astrology.
Seeds need oxygen from the air to germinate. Growing mediums that are too moist (soggy) will cut off oxygen supplies and the seeds will literally drown. Cannabis seeds germinate best when moisture is between 60 and 70 percent.
Cannabis seeds need only water, heat, and air to break dormancy and germinate; they do not need extra hormones, fertilizers, or additives. Seeds sprout
Mandala Seeds places great emphasis on the quality of the seed stock. We guarantee that the seeds from all products are fresh and viable when they are dispatched to resellers and customers. 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.
Germinating cannabis seeds is not difficult.
We provide the basic information and many hot tips on what is important to support you in having a successful start!
Understanding Risks of Pre-Germination
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?
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.
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.
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.
We work with distributors who enjoy the best reputation in the industry for professional storage and service. Our resellers are supplied by us directly or through our distributors. Although we make an effort to identify any black sheep in the cannabis seeds market it is impossible for us to monitor resellers all the time.
Customers should make sure that they receive their seeds in the original Mandala Seeds packaging to prevent fraud. We cannot guarantee authenticity for seeds that have been removed from the sealed Mandala packaging. When you purchase our seeds from a reseller you should receive 1st class seeds: mature, healthy colouring, with well-defined mottled skin. If you get seeds that are tiny, greenish/yellow, scuffed, or immature, these are not original Mandala Seeds!
We are not responsible for the sales and services offered by resellers. However, if you have any serious suspicion or complaint regarding your purchase please contact us with a copy of your order transaction and reseller details. The order must not be older than 2 months from date of purchase. We do not replace seeds on an individual basis. Replacements are only processed officially via the distributer, in the event of a faulty or damaged shipment sent out to the distributor and subsequently sold to the reseller.
How to Germinate your Mandala Seeds
Please use high quality soil that is suitable for seedlings (see our SOIL GUIDE for more info), or use rockwool starter cubes for germinating seeds.
Do not use jiffy’s/peat pellets: the acidic pH of pure peat can inhibit germination of cannabis seeds. Results are unreliable and depend on manufacturers, some add limestone to raise pH, some do not. Growers have also experienced problems using rapid rooter plugs (with various types of cannabis seeds). Any growing medium used for germination must also have the correct pH for cannabis seeds.
For optimal results we advise against the use of jiffy’s, peat pellets, and rooter plugs. If you are absolutely keen on using such products you should at least test the product first with a few expendable cannabis seeds before sowing your valuable seed collection.
Take 8-10 cm/3-4” (diameter) pots or a seedling tray and fill 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 and properly watered, but not soggy or waterlogged. The pots or tray should also not stand in a tray filled with water. Use a spoon or small beaker to dosage properly if you are unsure and want to avoid accidentally overwatering the soil. Put the pots or tray at a warm location and ideally under lighting. 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 effective. You should water the pots properly if the soil surface dries up. Within 3-7 days the seedlings should appear out of the soil. You can switch on your lamps during germination to provide warmth or when the first seedlings appear. Since they might also grow out of the soil during the night it’s best to have lighting switched on 24 hrs.
Immerse the rockwool cubes in lukewarm 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 (i.e. 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 3-5 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.
You can switch on your lamps during germination to provide warmth or when the first seedlings appear. Since they might also grow out of the cubes during the night it’s best to have lighting switched on 24 hrs.
IMPORTANT: Don’t cover pots with plastic wrap, don’t use a humidity dome to seal off the pots, 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 will rot before they can germinate. Excess humidity combines 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 (i.e. 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.
Heating mats should be avoided unless you need it in the wintertime. A dysfunctional heating mat, or a mistake in the temperature control, can easily boil the seeds or dry up the substrate and shrivel the freshly 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.
A #1 seed killer is a closed humidity dome/mini-greenhouse.
Humidity domes are only required for rooting cuttings.
Many growers make the mistake of thinking that they need a high ambient humidity for germination or seedlings. This is an unfortunate myth of cannabis cultivation. The high humidity and lack of fresh ventilation quickly causes fungus in the soil or growing medium and the seeds can rot!
Cannabis is not an orchid or swamp plant! The seeds need a well aerated growing medium to germinate well. Seedlings also cannot tolerate high humidity and can easily be attacked by fungus such as fusarium and pythium. Only the soil or growing medium should be moist for optimal germination and seedling growth. Ambient humidity is best at or below 50%.
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 at or below 50%.
Example of a Safe Set-Up
This Indoor Grow Garden includes reusable trays that can grow the plants for a week until transplanting into a bigger pot. The trays sit beneath 2x2ft 24W fluorescent bulbs for healthy growth. This setup provides light & warmth, it also ensures that fresh air & average humidity levels prevent negative factors from disturbing germination. The lights are housed in the canopy of a sturdy aluminium stand that has an adjustable height (up to 38cm H from base) and a reflective hood to maximize usable light. There are many different models of fluorescent or CFL fixtures on the market to suit every taste and budget. Give seedlings maximum light to prevent stretching and support fast development. Use additional light from a window if available. For best results we recommend HPS lamps from the start. A 70-150W HPS lamp does not use more electricity than standard CFL lamps but provides much more lumens (light intensity). If you are growing with 250-600W HPS then you should germinate or put your seedlings under the lamp as soon as possible to ensure quick and vigorous growth.
Things to avoid
- soaking seeds in water/wet paper tissue
- humidity dome/mini-greenhouse fully covered
- heating mat too hot
- covering pots with plastic
- germinating in jiffy’s and peat pellets
- wrong soil for germination
- fertilizing seedlings
- too much/too little water
- cold and dark germination room
- cold outdoor temperatures; frost
- wrong pH of water
- bad water quality
- high EC of nutrient solution in hydroponics
- spraying seedlings with water/organic teas/pesticides
Tips for Germinating & Planting Outdoor
There are various handy gardening items that protect seeds and seedlings from the cold, wind, and pests. Seeds can be sown outdoor if the daytime temperature is above 20°C/68°F and well above freezing at nighttime. The higher the temperature the faster the seeds can germinate and the less prone they will be to fungus (which especially loves cold and damp conditions). If you are in a cold climate and want to start early, but do not have a heated greenhouse, it is best to either germinate indoor or at least move the cups/tray inside for the night. Seedlings and sown seeds require protection from pests and insects. Ants and birds can be quite diligent in stealing seeds out of the soil for example. We have compiled some of the most common techniques and supplies for outdoor gardening. These items can either be purchased online or at garden supply centers.
Portable cold frames are great for protecting germinating seeds or seedlings. They can be moved to the sunniest spots in your garden or carried indoor. This is a standard model with polythene and wooden frame. The adjustable lid let’s you regulate heat and humidity.
A state-of the-art cold frame that can be used at the beginning of the growing season to insulate tender seedlings when outdoor temperatures drop too low. The UV resistant polycarbonate is as clear as glass panels and virtually unbreakable. Two easily adjustable, fully removable lid panels allow for variable ventilation and easy access from both sides, which are also held securely when closed.
This robust & portable 1m x 50cm Mini Garden combines the benefits of a raised bed propagator and cold frame into one to allow convenient growing from seed in an outdoor space. The large inside area and numerous vents enable easier control of humidity levels and temperature. The bottom tray can be raised up or down. There is enough height to accomodate seedlings and young plants.
A simple low-cost cloche is very handy if you need to transport the pots from inside to outside daily.
This thermal twin-walled UV stabilised polypropylene cloche is a standard model for outdoor that offers basic protection against pests, wind and rain. You can easily lift it and put it aside by grasping the top handle.
A longgrow super cloche has a rugged steel frame covered with corrugated PVC. It withstands extreme weather and is therefore a good choice for protecting seedlings if you are growing in an area with stormy weather during springtime. The ventilation is regulated by circular panels at the rear ends.
High grade (30 gsm) polypropylene fleece covers these easy tunnels, creating warmth and insulation whilst allowing water and sunlight to filter through – a constant atmosphere is maintained for faster, even growth and protection against frost, strong sunlight and pests.
A practical solution is offered by this portable and easily assembled lean-to greenhouse. It has a heavy-duty galvanised steel framework with zip-on and zip-off heavy-duty UV stabilised PVC covers. The greenhouse is ideal for propagating and hardening off young plants and offers essential protection from frost, weather conditions and pests.
Within 3-7 days the seedlings should appear out of the soil/rockwool cubes.
Provide sufficient light. 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. Seedlings should be moved directly under a HPS lamp if you have one. The more light your provide the better your plants can grow. Not all Mandala strains are suited for low light such as CFL lamps and fluorescents. Make sure you choose the right strain for your lights.
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 containers if you are confident that you will not over-water. We recommend a 4-5L/1 gallon container for the first 4 weeks of growth and subsequent period of sexing under 12/12. Repot females into larger containers after sexing. See our SOIL GUIDE for info on container sizes.
Start with a mild EC such 0.7-0.8 and slowly increase the EC of your nutrient solution after one week of growth. The best EC depends on the quality of your water and it’s basic EC level. If the water has a high EC then you should filter it with a household reverse-osmosis filter and mix this 50-50 with tap water.
Do not fertilize in the first weeks of growth on soil! This is the #1 cause for sick plants. Transplant into quality horticultural grade potting soil and bigger containers as the plants grow larger. Rootbound and sick plants should be avoided. Mandala plants grow quicker and more vigorously than most other strains. Do not let your good plants vegetate in tiny cups and cramped pots. You can get a high % of males or male flowers on your females if you do not care for your plants properly.
- 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 fertilizers 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). The correct pH is essential for healthy growth! For soil it should range between 6.2-6.5. In hydroponic systems start with 5.6-5.8 on fresh rockwool cubes, or 5.8-6.0 on new expanded clay pebbles if they are not pH neutral. Check the pH of drained water in hydroponics and adjust the pH as required.
- 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. None of these products have been adequately scientifically tested on cannabis by manufacturers!
- 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. Repot quickly if you germinate in small cups. Rootbound plants quickly develop nitrogen deficiency and other deficiencies. “Rootbound” is a condition which exists when a potted plant has outgrown its container. The roots become entangled and matted together, and the growth of the plant becomes stunted. Rootbound plants can lead to a higher % of males and trigger male flowers on female plants!
Please note: Cannabis seeds are a biological product. We therefore do not carry responsibility for germination rates once the seeds are dispatched to the resellers or customer. The reseller and customer is responsible for proper storage and handling of seeds.
What you need to know about growing in soil, how to buy the best soil product, organic additives, etc.
Use our feature chart to compare Mandala strains and find what you are looking for quickly.
Choose the right Mandala strain for your location using a highly detailed climate guide and special info’s.
How to germinate your Mandala cannabis seeds and care for seedlings.