There are many to consider when germinating cannabis seeds — not only the germination method you choose but also the conditions your seeds require to thrive. Did your cannabis plant just die for no apparent reason? Frustrating, isn’t it? There is a whole range of reasons why this might have happened and in Learn how to kill weed seeds in soil to prevent weeds and other invasive grasses from continuing to sprout every year.
Care and Caution When Germinating Cannabis Seeds
For growers looking to produce top-shelf cannabis, it all starts with the seeds. Rich Hamilton explains there’s far more involved than simply burying a seed in a pot of dirt.
There are many to consider when germinating cannabis seeds — not only the germination method you choose but also the environmental conditions your seeds require to thrive. These conditions include temperature, light exposure, moisture, and oxygen levels. Get any of these wrong and it could spell the end for your grow before it even begins.
Cannabis seeds can be very delicate and temperamental even when germinating in the perfect conditions. You can understand why you should approach this task with best-practice knowledge and caution.
To try and give your seeds the best chance, we are going to look at some tips and methods to help you get better results, first time, from your germination efforts.
Firstly, what is germination? Well, germinate means “to bring to life.” Germination is the first part of a plant’s life, the growth or shooting of a seed into a seedling and then hopefully a plant.
Cannabis seeds germinate via epigeal germination which sees the cotyledons (seed leaves) pushed upward and out of the soil as the plant begins to grow. For germination to occur, several natural elements and conditions must be present in the correct ratios. Let’s have a look at them.
Water — This is needed to start the germination process as the seed is dry, holding only five percent water and needs to absorb a lot more to begin the germination process. Seeds store starch, oils, and proteins and when germination begins, hydrolytic enzymes are activated, releasing the stored supplies and giving the plant just enough of the right chemicals to get it started. Water is also needed to expand the seed’s shell and soften it, allowing it to split for the beginnings of the plant to emerge. The hardness of a cannabis seed shell can vary quite a lot. If your seed is ripe and mature enough for germination, then you shouldn’t have any problems. A more immature cannabis seed, however, will have a more rigid shell and may fail to germinate.
Oxygen — Seeds need to breathe, but without oxygen the seed may drown or suffocate. Overwatering can suffocate your cannabis seeds preventing oxygen from getting to them, so keep them moist but not soaked. Don’t overwater your seeds — use a spray mist rather than pouring water directly onto them.
Temperature — Ideally, your cannabis seeds will germinate best at their “sweet spot” between 70-75°F. If you germinate a cannabis seed outside this range, then it can negatively affect the plant’s growth and health in the future. When temperatures are too cold, it can ultimately stunt germination so keep seeds away from any drafts, open windows, or fans.
Light conditions — Cannabis seeds germinate best in dark conditions. During germination, your cannabis seed is working to develop its first root (the radicle), and roots (unsurprisingly as they exist underground) do not like light! It is therefore vital to keep your cannabis seeds somewhere dark until transplant. But as soon as germination occurs and your new seedling develops leaves, it will need to be exposed to light to start the vital task of photosynthesis. Now that we understand what your cannabis seeds need, let’s explore the most popular methods used to germinate them.
The Glass of Water Germination Method
You can leave your cannabis seeds in a glass of mineral water in a dark environment until the radicle/tip of the root shows.
Depending on the seed strain, you should generally see something happening within one to five days. Why mineral water? Well, depending on where you live, your tap water can vary immensely in terms of chemical composition and pH. The ideal pH for water when germinating is pH 7. Anything outside of this can have adverse effects on your seed. Using mineral water is a cheap and effective way of keeping a stable pH environment. If you use tap water, however, leave it to stand for 24 hours first. The tap water needs a chance to settle and dissolve any chemicals that are present and may be harmful to the seeds.
You can use an air stone and pump to oxygenate the water whilst it stands for 24 hours. By doing so, you will reduce the chance of the seeds drowning and helping to dissolve any unwanted chemicals at a faster rate.
The Paper Towel Germination Method
Using a paper towel to germinate your cannabis seeds is both reliable and straightforward. You should find that 90 percent or more of your cannabis seeds will germinate when following this method correctly.
Take a sheet of premium paper towel and fold it in half, then place the seeds to the left of center. If you are germinating more than one seed, then you can use the same piece of kitchen towel but do not let the cannabis seeds touch each other. Now fold the kitchen towel in half again so all the seeds are covered up and then saturate it with water.
Mineral water is excellent to use, or if you are going to use tap water, then follow the recommended process for the glass of water method as previously discussed. Now leave the kitchen towel on a plate in a dark place as the roots will hopefully begin to develop soon and they do not like the light.
Humidity levels are equally important and keeping the seeds in the paper towel will keep the humidity levels where they should be. Keep the kitchen towel moist at all times and do not let it dry out. If you have been successful, it should take about two to four days for you to see until the radicle begins to emerge.
It is best practice to place the moist kitchen towels between two clean plates. Doing so helps to stabilize temperature and humidity and block out any light. The plates should be face-to-face, with the germination towel in between. Once a cannabis seed starts showing signs of successfully germinating, you can easily remove them whilst leaving the others, which may not yet have germinated, undisturbed.
Direct Germination Method
Germinating “directly” is where you place the cannabis seed directly within a pellet or block of a medium of your choosing. You can germinate your seed within a soil or coco pellet, however, I would recommend choosing a one-inch rooting sponge or stonewool cube.
You can use a soil pellet, but the risk here is that soil already contains a certain level of minerals and elements that could cause an imbalance in your seed, affecting its development later on in life.
For seeds in their natural environment, there can be double, triple, or a hundred times more plants growing in the soil at any one time. From those plants, thousands of seeds are dropped for germination and of those thousands, only half may germinate, even under natural conditions.
We are trying to grow our seeds under controlled conditions and in much smaller numbers. The margin for error, therefore, is much smaller. Using a rooting sponge is an excellent alternative for germination as it eliminates any risk of deficiencies or toxicities you may otherwise experience when using a natural medium such as soil at this early stage.
The direct method of germination can be hard to control as you must wait until the seedling first shows itself out of the chosen medium to know whether it has been successful or not.
As the cannabis seed is buried within its medium, you cannot check on it during the process to see if it has begun the germination process. As a result, this process can take much longer than the methods already discussed.
If you are germinating “directly” then firstly you should moisten your medium by misting it with a spray bottle. The cannabis seed will then need to be carefully inserted into the chosen medium and be surrounded by its encasing environment to keep any light out.
Now that you have chosen your method and you have successfully germinated some seeds. What now? How do you know when you should transplant? If everything goes according to plan with your germination efforts, you will see the radicle/root tip of the cannabis seed breaking through the shell. This new root is the first sign germination has occurred. It is best to transplant each seedling when the radicle is around three times the length of the seed.
A rooting sponge is a perfect choice for transplanting as it is compatible with whatever medium or system you use later. Rooting sponges are also an excellent choice for those who are looking to sell their seedlings.
Rooting sponges and stone wool blocks make for more robust root systems. It can take longer for the roots to break through, but when they do, they will be stronger.
When you are transplanting the seed, it must be placed radicle first into its new home, quickly, gently, and precisely as it only has a minimal amount of energy to survive and develop into a seedling. Once your seeds are transplanted, they should go into a propagator, ready for the start of the growth phase of their lives. Your cannabis seed holds all the potential to give you the vibrant, robust, healthy plants, and bountiful yields you desire.
Taking the time and care to get your seeds off to a good start should be a no-brainer. Knowledge is power if you want to be a better grower, so think of the learning process just like a seed itself. Nurture it, cultivate it, and you will soon harvest success.
How to prevent the death of cannabis seeds and seedlings
Every grower, almost without exception, will have occasionally suffered the death of a plant during cultivation, just when it seemed that everything was going along nicely. In this article, we’ll focus on the main reasons why seeds may not germinate properly, or why seedlings may end up dead in the first weeks of life.
Seeds dying before germination
Cannabis seeds can die even before we start to grow them, in which case, when the grower comes to germinate them, they won’t open up and sprout at all.
The seeds of the cannabis plant, like many other types of seeds, must always be kept in the correct conditions, especially if you want to save the leftover seeds for later use and ensure that they germinate well in the future.
The same goes for unopened whole packs of seeds that have been purchased to store for later use. Sometimes, certain varieties are in high demand and there is limited stock, so the more astute growers will make sure they grab a few packs to keep in the vault until they find the time to germinate the cannabis seeds.
Cannabis seeds must be stored in the correct conditions
What to do with leftover seeds or unopened seed packs
Cannabis seeds need very low relative humidity and relatively low temperature for their proper storage, so the best plan is to keep them in a “no frost” refrigerator, in which both the humidity and temperature are maintained at very low levels for better conservation of food.
If we want to keep a seed package that’s still sealed, simply put the whole unopened pack into the fridge. The best place for its conservation is usually the small shelf where the eggs or butter are kept, although really any part of the fridge is ideal for storage.
If we want to save the leftover seeds from a pack for later use, we recommend storing them in the original Eppendorf tube or container used by the bank. In the original packaging, these Eppendorf tubes hold the seeds and usually also contain a few small silica gel balls, included to maintain very low humidity (10 to 20%) and help to ensure that the seed does not lose any germination viability.
If, however, we leave the seeds for a long period of time in any corner of the house it is possible that over time their viability to germinate will decrease, and when we plant them they may take a long time to germinate or indeed not germinate at all. it is also important to protect them from sunlight.
So if you wish to save the seeds in the best conditions, always keep them in the refrigerator, well protected from air, light and moisture.
How do we store leftover seeds to grow at a later date?
Death during the germination of cannabis seeds
Death during the germination of cannabis seeds is one of the most frequent failures suffered by every grower over the course of his or her cultivation career. There are several possible reasons that can lead to the seeds dying before they even open and begin to grow, which we’ll examine here.
Not all seeds have the same resistance to the errors that may occur during the germination process. Just as not all siblings are not all equal, neither are all seeds. By this, we mean that in the case of one seed germinating and the rest of them not doing so, it doesn’t necessarily mean that those that didn’t germinate were not strong or resistant, but simply that they were less so than the one that did germinate. If this occurs, we must ask ourselves why they did not germinate and look for any possible failings in the process.
Death by drowning the seed during germination
We start from the basic premise that the seeds require moisture, oxygen and a suitable temperature for germination; If one of the three aspects is not taken into account, it is quite likely that the seeds won’t end up germinating.
Putting the cannabis seeds in a glass of water and waiting 24 to 48 hours for their germination can be a fatal error for them. Re-hydrating the seeds in water is a good idea as long as they are not out of contact with the air for long, as they will be deprived of oxygen and most of the time they will end up dying; so if we use this method, we only leave them to re-to hydrate in water for a few minutes, although, preferably we will avoid any previous soaking or re-hydration (which in any case is not necessary).
We must maintain suitable levels of humidity for germination
The reason for this is that tap water contains chlorine, which sterilises the water to make it suitable for domestic use. However, this chlorine disappears by evaporation after a few hours, so if the water then gets contaminated, the seed can be attacked by any number of pathogens and eventually die. This example also illustrates why we must always touch the seeds with clean hands; If the seeds are handled with dirty fingers, it can lead a fungal or bacterial infection to contaminate them and severely compromise their development.
The same can happen in other germination media such as jiffy plugs, where the most common mistake is usually not draining away the excess water after re-hydrating the compressed peat. To this error, we can add that of burying the seed at more than twice its own depth, in which case it may not emerge despite having germinated perfectly well, but instead, simply end up rotting due to excess water and lack of oxygen. This error is also frequent in growers who germinate directly in the soil because when they first irrigate, the seed can be washed down into the soil resulting in them being buried too deeply, which makes it difficult for the seedling to reach the surface. It is always better to wet the substrate first, before sowing any seeds.
If you want to sow the seed directly into the soil and do it properly, when growing outdoors you must also act to prevent seed predators. Ants, birds, and many other animals or insects are another common cause of seed failure during germination. In the case of ants, they eat the small, delicate root, leaving the plant unable to develop and condemning it to imminent death.
Placing the seeds between moist serviettes/paper towels is one of the best germination methods for beginner growers. Since you can easily see if the seed has taken root or not. But we must also bear in mind that the germination medium, the kitchen paper, is made of cellulose, meaning it is an organic material that will decompose and rot, just like any product of this type.
Planting the germinated seed is also a crucial moment
It is, therefore, obligatory to change the napkins every day and a half, more or less, to avoid the seeds being contaminated by the pathogens that can appear as the napkins begin to rot. For this reason, we recommend placing the napkins in a deep plate and covering it with another one, leaving a small gap between the two so that air can enter, oxygenate the microclimate that is created during the germination of the seeds and avoiding them rotting.
Seeds dying due to lack of moisture
Just as excess water is one of the most common causes of germination problems, the lack of moisture is equally detrimental to the process.
If outdoor temperatures are around 20 to 24ºC, then we shouldn’t need do much more than start the seeds to germinate and wait for them to open, following the precautions already discussed. But in case of having warmer or cooler temperatures, we must act to raise or lower the environmental temperature for optimal germination, and find the best location for germination to be successful.
If it is winter, the plates holding the seeds are often placed on top of a low heat source to raise the temperature. We must, however, be careful: if this heat source emits hot air, the paper towels will dry out and the seeds will run out of moisture, affecting germination. If you realise this in time, you can re-hydrate the seeds and they will usually recover from and continue to germinate, although it is also possible that there will be consequences that may affect the subsequent development of the plant during its cultivation.
Not long after sowing the seed, we will see our little plant emerge from the soil
If we haven’t noticed soon enough that the seeds have been left without moisture, we can assume that they will have dried up completely, with their consequent death, and this is even more likely if the seeds had already opened up to show the root. This can also happen very easily if we germinate during summer when temperatures are high and humidity is usually very low compared to other times of the year.
Death of the plants during the growth period
The start of the growth period is a very important stage in a plant’s life, so several aspects must be taken into account so that it does not die of any of a number of causes.
One of the most frequent problems is root rot due to excess irrigation and lack of oxygen in the substrate. Up till now, this has been one of the most common causes of plant death during the growth period, especially with beginner gardeners who lack previous cultivation experience. In addition, the likelihood of this happening increases considerably in crops with auto-flowering varieties; we’ll explain what to do here.
When the plant emerges from the substrate, leaving behind its germination stage, it is crucial to take care with any excess water and the lack of humidity in its aerial parts such as leaves, stems and branches.
The proper conditions guarantee good germinación
When the plant is young and only has a very small root, its needs are few, it feeds and drinks very little. If we saturate the substrate with too much water, apart from halting the growth of the root (leading to little or no growth in the aerial parts), it creates the ideal conditions for the small roots to slowly rot. If the plant loses a part or all of its tiny root system in its first stage of life, it is almost guaranteed that it will die within a few days.
If we use a small 0.5L to 1L plant pot for the first part of vegetative growth, before transplanting them to a bigger pot, we will be covering our backs in case of any excess of irrigation, since the substrate will dry out again much faster than in larger pots. For this reason, this issue is very common for novice growers who are cultivating auto-flowering cannabis plants, where the use of 20L pots is recommended from the start.
It is often said that you must irrigate with an appropriate amount of water and nutrients for the size of the plant. As this is often complicated to carry out, as a rough guide we can irrigate the plants with an amount not more than 10 or 20% of the plant pot’s capacity. So, if they are 1L pots we will water from 100 to 200ml as long as it is not an auto-flowering plant.
If the plan is to grow automatic varieties, then during the first two weeks we water with 100 to 350ml per irrigation, every 1 or 2 days. Remember that the substrate must maintain a minimum of humidity to allow the plant to feed and continue to develop normally. If it is raining and the plants are outdoors, it’s a good idea to move or cover them, to prevent the substrate from getting soaked, which could easily lead to root zone problems.
The first stages of growth survived with success!
We hope that this information will be useful and help to stop your seeds and seedlings dying. Don’t hesitate to leave any comments or questions, we’ll be pleased to help.
The articles published by Alchimiaweb, S.L. are reserved for adult clients only. We would like to remind our customers that cannabis seeds are not listed in the European Community catalogue. They are products intended for genetic conservation and collecting, in no case for cultivation. In some countries it is strictly forbidden to germinate cannabis seeds, other than those authorised by the European Union. We recommend our customers not to infringe the law in any way, we are not responsible for their use.
How to Kill Weed Seeds in Soil [5 Easy Methods]
To kill weed seeds in soil you will have to apply one or more of the following methods:
- Heat soil to temperatures high enough to kill weeds seeds
- Force seeds to sprout and destroy growing weeds
- Apply chemical or natural weed killers that prevent weeds from sprouting
- Use flame weeding to destroy weeds and seeds at once
- Layer mulch in garden areas to suppress weed sprouting and attract insects that eat seeds
With this arsenal of tricks for killing weed seeds before they sprout, you can stop the spread of weeds in both your lawn and garden.
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5 Tips for Killing Weed Seeds
Rather than spending time and effort battling weeds as they sprout, attack weeds at the source by killing weed seeds. Each of these methods destroys weed seeds, which ensures you won’t have to battle recurring weed invasions. Try these ways to get rid of weed seeds yourself.
Soil solarization is a very powerful method for killing weed seeds. Weed seeds begin to die if soil temperatures surpass 108 degrees, with full seed death ensured by soil surface temperatures of 140 degrees or more. Solarization uses clear plastic tarps to trap heat at the soil surface, killing weed seeds within the tarped area. To solarize an area, follow these steps:
- Clear the area of all vegetation through use of a hoe or other garden implement. Remove any woody stumps
- Till the soil to further break up any weed root systems left behind.
- Rake away all vegetation residue
- Water the tilled and cleared soil with a garden hose until it is damp.
- Lay a sheet of clear plastic over the area. Weigh it down tightly at the edges
- Leave the plastic in place for at least two months.
Solarization is the best method to reclaim a weedy garden or other area. It is a “clean slate” for your soil, because seeds will be destroyed by the solar heat trapped beneath the plastic.
It is typically tough to implement solarization in large areas and is not usually suitable for use in lawns, where you may want to preserve grass or other plants. Pre-emergent weed killers and flame weeding are much better for use in lawns.
Till and Kill
Weed seeds can lie dormant in soil for decades and are only “activated” when brought to within an inch of the surface. One method to rid soil of dormant weed seeds is to force these dormant seeds to sprout, then attack them with a powerful natural or chemical weed killer. To do this:
- In spring, till the affected area. Tilling brings dormant seeds to the surface
- Water the area for 1–2 weeks with a sprinkler or soaker hose
- When weeds begin to sprout, apply the weed killer of your choice
This is another “clean slate” method, where you force weed seeds to show themselves and then kill young weeds before they mature and cast seeds. Because of the invasive tilling step, it is not best used in areas with desirable grasses and plants.
Use Pre-Emergent Weed Killer
Pre-emergent weed killer stops weeds in their tracks. It works by attacking weed seeds just as they begin to germinate, killing them before they even poke above the surface. It’s a weed killer so good, the only sign it’s working is that there will be no new weeds at all.