The thing is, weed isn’t just weed. There are big differences in growing characteristics among different cannabis seeds. An indica autoflower will certainly behave differently than a picky photoperiod sativa. Some strains may be suitable to grow in a colder climate, while others may require a hot, sunny environment. Some strains may need lots of nutrients, while others require only light feeding. You get the idea.
Correct pH levels
2. BAD GERMINATION
Fill a small seedling pot with an unfertilised or “light” potting mix. Poke a small hole about 1cm deep in the middle and place your seed inside. Cover lightly with soil. Water the soil and cover the seedling pot with clingfilm to lock in moisture. Seeds should germinate in a few days.
It does happen: Someone hands you a bag of seeds of “some great weed” for you to grow. You’re happy since you just saved some cash on seeds. The problem is, you don’t know what type of cannabis the seeds are, whether it’s sativa, indica, autoflowers, etc. We’re already off to a pretty bad start.
Even if every stage up to harvest has gone splendidly, the final (and most maddening) mistake you can make is harvesting too early or too late. You don’t want to make the chop before your buds reach peak potency, but you also don’t want to leave them hanging, so to speak.
This is the beauty of seeds—often, you can tell which plants or genetics will thrive right from the get-go. This will help you determine which plants you want to take cuttings from for clones or for breeding if you want to create a seed bank of your own.
Marijuana seeds can be acquired from an array of sources and can vary in quality. For more info on how to buy marijuana seeds, check out our Guide to buying cannabis seeds.
Also, buying from a reputable breeder or seed bank will give you a sense of what a particular strain will look and smell like, how it will grow, and how much it will yield at harvest.
If buying from a reputable breeder or seed bank, growing from seed is the best way to ensure your plants will have solid genetics and start clean, meaning they won’t come with diseases or pests.
To get the buds found in medical and recreational stores, female cannabis plants are grown in an environment without males—or the males are removed from the area before they release pollen—so the females don’t create seeds. Females can then focus their energies on producing buds and not seeds—this high-potency marijuana is traditionally known as “sinsemilla,” meaning “seedless.”
The main drawback to growing from seed is there is no guarantee as to what you’ll end up with—if you buy a regular pack of cannabis seeds, it will be a mix of males and females. You’ll need to sex them out (more below) to identify the males and get rid of them, because you don’t want your females producing seeds.
Autoflowers don’t need lots of nutrients because they’re small and don’t spend much time in the vegetative cycle. They won’t need as much veg nutrients—such as nitrogen—but will need more bloom nutrients.
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.
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.
Just as excess water is one of the most common causes of germination problems, the lack of moisture is equally detrimental to the process.
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.
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 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.
Cannabis seeds must be stored in the correct conditions