Cannabis seeds will usually remain viable for about 2 years after they are produced by a female plant. By providing better storage conditions, seeds can last for up to about 5 years. To keep them viable for as long as possible, they should be stored in an area that is cool, dark, and dry.
When you decide a seed is ready to grow a plant from, you will have to initiate plant growth by germinating the seed. Germinating a marijuana seed is comprised of supplying the seed with moisture and keeping it in a dark place that has a fairly constant warm temperature.
When the appropriate conditions are given to the seed for a long enough time, the plant will sprout a root. After the root is about a quarter of an inch long, the seed can be placed in an environment where it can grow.
Seeds can be germinated in different ways, depending on the intended growing environment. If you plan on growing marijuana hydroponically, you can germinate the seed on paper towel or directly on a small piece of the media that will be used in your hydroponic garden, by following the method described below.
If you are going to be growing marijuana in soil, you can germinate the seed directly on the spot where it will grow. Simply place the seed where you want the plant to grow and cover it with a small amount of loose soil (maximum of a half inch in depth). The soil on top is to help ensure darkness and retain moisture but is not essential.
Keep the soil around the plant moist (not wet) by spraying it with distilled water, reverse osmosis water, or tap water (aged for at least 3 days) applied by a hand sprayer. Keeping the seed moist but not wet may not be possible, especially if you are growing outdoors. So you may wish to germinate your seeds indoors first then transplant them outside.
A Personal Method
Just about any seed can be germinated in this manner, from tomatoes to marijuana. Instructions are given here for using paper towels because it works best for me.
However, you may wish to try germinating directly on the media that you will be using in your garden (if you are hydroponic marijuana grower).
Keep in mind rockwool and other media might have to be soaked in pH adjusted water prior to use, especially when seeds are involved. Follow the manufacturers instructions.
What You Need
- a plate
- a bowl
- marijuana seeds
- paper towels (or hydroponic media)
The plate will have to have a flat center area and the bowl will have to fit in that center area of the plate.
Take your plate and bowl and run boiling hot water all over them to minimize any chance of contamination, you should do this to the paper towels also making sure they don’t fall apart. Then squeeze the paper towel until it does not drip water unless you squeeze it a little.
Take the 1 or 2 sheets of paper towel and carefully fold them till they fit into the bottom of the plate. Turn the bowl upside down and place it over the plate, the paper towel should not stick out around the outside of the bowl.
When the paper towels reach room temperature, remove the bowl and place the seeds on top of the damp paper towel then cover them with the bowl again (some people also like to put another damp layer of paper towel over the top of the seeds).
The plate and bowl should be dark enough to block sunlight or kept in a dark area or covered to block sunlight and stored in an area that is clean and warm.
Check at least 1-2 times daily and add small quantities of water when needed to keep the paper towel moist. Tap water probably contains chlorine and other elements that are not seed friendly.
If you only have access to tap water, allow it to age uncovered for at least three days. Better still, use distilled or reverse osmosis water.
When the seeds sprout, and the white shoot emerges about a quarter inch, transplant (root down) into your hydroponic garden or soil. Treat very gently, don’t touch or break the root tip.
If you started on hydroponic media you can place the media containing the seed directly into the garden without touching the seed itself. This is a good idea because a minimum of stress is caused to the plant.
Buy Marijuana Seeds
Some seeds take up to 12 days to germinate, but most will germinate within 24 to 72 hours. Be patient, give your valuable seeds a chance to sprout before tossing them out.
I’ve never tried but if you require more room to germinate your seeds, you could try a suitably sized pot or pan with a lid to preform the same function as a plate with a bowl placed over it.
Do not use bleach or mix bleach with the water!!
Never, never let the paper towel dry out!!
Soil growers who plan on growing marijuana either indoors or outdoors can use a mini-greenhouse with a heating element. These are used to germinate the seed and let it start to grow and establish a root system in soil, without being transplanted.
Seeds are germinated by placing soil in the tray of the mini-greenhouse and moistening it with water. The seed is then placed in the soil, and the top section is placed on the greenhouse. The greenhouse is moved to a dark area and the heater is plugged in.
After the seed has germinated, the heat is stopped and the plants are supplied with about 16-18 hours of mild light per day (fluorescent, led, or diffused sunlight only, not metal halide, high pressure sodium, direct sunlight, or any source of strong light) and allowed to grow a bit before being transplanted into the soil that they will be grown in.
Temperature And Marijuana Seed Germination
An average temperature of about 70-75 degrees F will be fine for germinating most seeds strain. But higher temperatures might be necessary to ensure optimal speed and health when germinating seed strains that originated in areas where it is very warm all year long.
If you don’t know where your seed strain originated, try germinating a single seed in an area where the average temperature is 70-75 degrees F. If your seed doesn’t sprout, try germinating another seed at a temperature 5 degrees F higher until you find what temperature works best.
Of the 20+ marijuana strains the author has grown, only 3 marijuana strains had problems germinating at temperatures between 70-75 degrees.
The strains that wouldn’t sprout in an area where the temp was about 70 degrees (average temp) were moved to an area where the temp was about 75 degrees (average temp) and still didn’t sprout. So another seed was started in an area where an average temp of 80 degrees was maintained.
It was only when these seeds were germinated at average temperatures of 80 degrees fahrenheit or higher that they sprouted. All the strains that required fairly high temperatures to germinate were equatorial in origin, so they need hot weather conditions (like in nature where they come from).
When germinating marijuana seeds:
- Most seeds will germinate at 70-75 degrees F.
- Nearly all seeds do best at about 78-80 degrees F.
- Some seeds may require temperatures up to 80-85 degrees F.
- Never exceed 90 degrees F when germinating marijuana seeds.
- When required, a seedling heat mat can be employed to raise and/or maintain a higher temperature when germinating seeds. Most heat mats radiate heat on both sides, so when warmer temps are required, you can put some kind of insulation (rigid styrofoam works well) under the mat and more heat will be radiated upwards.