How to Plant (and Transplant) Cannabis Seeds for Maximum Success
Updated on July 8, 2022
In this lesson, you will learn:
Most plants just require a seed, dirt, and water to start growing. And the same is true of cannabis. This weed plant, for example, grew in sand and was given no nutrients or love.
This goes to show how resilient cannabis plants are. They literally grow anywhere. However, no one wants a tiny weed plant like that. In order to get large and healthy plants, dropping a seed in the ground won’t suffice.
Cannabis plant grown in sand
Did you know that...
Nearly 100% of legal commercial cannabis growers transplant their weed plants instead of growing directly in the final container? Academic research also shows that most crops yield more results when transplanted instead of directly sewn into the ground.
No more waiting. Let’s get right into it!
- Jiffy pellet or Rockwool plug
- Hydrogen peroxide 3%
- Tweezers or rubber gloves
- Dechlorinated tap water
- Transparent cup or dome
- Heating mat (optional)
Starter dome with Rockwool plugs and Jiffies
Heating mat for seedlings
Planting Cannabis Seeds For Success
When: right away
Soak your seeds in a solution with hydrogen peroxide 3% (1 part) and tap water (5 parts) for 24 hours prior to planting. This will help soften the outer coat of your seed while allowing more oxygen into it, which not only speeds up the germination process but also cleans out any unwanted pathogens. You can find hydrogen peroxide 3% at any pharmacy or Walmart. Keep them in a dark spot.
Seeds in hydrogen peroxide/water bath for 24h
When: after hydrogen peroxide soak is finished
Put your Jiffy pellet (if you are growing in soil) or Rockwool plug (if you are growing in soilless media like coco coir or Rockwool) in your dechlorinated tap water for 30 minutes. In order to dechlorinate your water, leave it exposed to air for 24h to 48h.
OPTIONAL: seedlings, like flowering plants, need a lot of phosphorus in the beginning. For this reason, it is recommended that you start your seedlings with a solution of BLOOM nutrients (not VEG) and tap water at an EC of 1.0 (meaning a very low dose of nutrients). This will ensure a strong start for your seedling, and once you transplant (next step) you can use your VEG mix.
Rockwool plugs in a bloom nutrient solution for 30 min
Jiffy pellets expanding in tap water over 30 min
IMPORTANT: if you are using Jiffy pellets, set your pH at 6.5, and if you are using Rockwool plugs, set your pH at 5.5.
"While you certainly can, there are some key disadvantages to it"
Paper Towel Method Disadvantages
If you haven’t yet, it won’t be long until you find growers starting their cannabis seeds in paper towels. We are not sure why it became popular, but all we know is that there is no body of research supporting this method. In fact, commercial cannabis growers don’t use this method for two reasons:
Cannabis seeds germinated using the paper towel method
The way we look at the paper towel method is as an unnecessary extra step. It doesn’t add any value, and instead only adds risk. Instead, we recommend starting seeds in a Rockwool plug (for soilless) or Jiffy pellet (for soil).
Learn to Grow Like The Pros
When: after Jiffy pellets or Rockwool plugs are soaked
Now that we have pre-soaked Jiffy pellets (or Rockwool plugs) and disinfected the seeds, it is time to plant them. Before starting, however, remove your Jiffy pellets or Rockwool plugs from the water, and lightly squeeze out the excess liquid. About 50% of the water should come out.
Pre-soaked Jiffy pellets and Rockwool plugs
Poking ¼” deep holes in the Rockwool plug
Cannabis seed's ideal position for planting
Planting a seed in a Jiffy pellet
Planting a seed in a Rockwool cube
Seeds sprouting inside a dome, on top of a heating mat
"Autoflowering marijuana plants are too delicate and must be directly sowed"
Planting autoflowering seeds for success
Planting autoflowers is not the same as planting regular photoperiods. The reason for this is that autoflowers have a very short lifecycle, and any external shock (such as transplanting) can reduce your yields significantly.
This means that, instead of planting into Jiffy pellets or Rockwool plugs, you should sow your autoflower seeds directly in their final pots (we recommend using rich soil and a light dose of nutrients in every feeding). You will also not be able to use a dome, which is why it is recommended to use transparent plastic cups instead (make a couple of holes on top of the cup to create airflow).
In order to accomplish this, follow Steps 1 and 3, and skip Step 2.
Autoflowering seedling planted directly in the final pot
You can then keep the cups on the seedlings until they outgrow them, at which point you should remove the cups and maintain your autoflowering weed plants at a temperature of 77F (25C) and a relative humidity of 70% to 80% for two weeks.
PRO TIP: we recommend planting autoflowers 2 inches away from the edge of your pots so that you can low-stress train them across the middle of the pots later, allowing for more light exposure and airflow. The photo below shows the same autoflower as the previous photo with the transparent cup, but 4 weeks later when it was time to start training it.
Autoflower that was planted on the edge of the pot
Want to train your plants like a pro?
" Easy peasy! The BudTrainer Transplanting Method has everything covered."
- Red solo cups
- Intermittent and/or final pots
- Your media of choice (use rich soil if you are a beginner)
- Nutrient solution with VEG mix
- Mycorrhizal fungi
Why should I transplant my cannabis plants?
Root structures of direct sowing vs transplanting
Transplanting Seedlings For Success
When: once the first set of true leaves is out and you can see some root tips around your Jiffy pellets or Rockwool plugs, it’s time to transplant your seedlings into a red solo cup so that it can continue growing its roots. This seedling, for example, is 1 week old and was just transplanted into a red solo cup. If you have other seedlings that need to catch up, you can wait until the 2nd set of true leaves comes out, at which point you MUST transplant into a red solo cup.
Cannabis seedling that was just transplanted 5 minutes ago
- Cut 4 small holes with your scissors or trimmers at the bottom of your solo cup. This will allow the runoff water to come out at the bottom.
- Fill 80% of your solo cup with soil or soilless media (we recommend using rich soil if you are a beginner), and tap it down on the table or use your fingers to slightly compress the media.
- Cut the net around your Jiffy pellet or the plastic on the Rockwool plug.
- (OPTIONAL) Sprinkle mycorrhizal fungi on your starter plug and media. This fungi grows on your roots and feeds nutrients to your plants in exchange for sugars, creating a mutually beneficial relationship and increasing your yields. If you have a mycorrhizal inoculant, sprinkle it on the root ball like you would sprinkle salt and pepper on a meal.
- Place the plug inside the cup, on top of the media. Add/remove media until the top of the plug aligns with the top of the cup.
- Cover the sides of the plug with media, and press down gently with your fingers. Repeat until you fill up the remainder of the cup.
- Water it with 100ml to 150ml of water (this is enough for the 1st week).
Transplanting cannabis seedlings into red solo cups
Cannabis root-ball from a red solo cup ready for transplanting
Ideally, you want to transplant into a container that is 10x to 20x bigger than the previous one. For example, a Rockwool plug or Jiffy pellet have about 1 oz of volume, and a red solo cup has 18 oz. This means we initially transplanted into a volume that was 18x bigger than the starter plug. From this red solo cup, the next recommended size will be 1.4Ga to 2.8Ga. Since we personally like to finish our plants in the 3Ga BudPots, we will go directly into our final pot. However, if you want to finish in larger pots, here is how and when you should do your 2nd transplant and your later transplants.
When choosing your pots, make sure to pick fabric pots as your final pots and plastic pots or single-use fabric pots for your intermittent transplants. Fabric pots are great for creating stronger root balls, but at the same time they are hard to transplant from.
- Fill the bottom of your new pot with media (we recommend using rich soil if you are a beginner) until you have enough to place the solo cup (or previous pot) inside and align its top with the top of the new pot.
- Place the solo cup (or previous pot) inside the new pot, exactly where you want it to be forever.
- Fill the new pot with media around the cup (or previous pot) as if you were burying it.
- Once the new pot is full, tap it down on the table or gently compress the media. Remove the red solo cup (or previous pot).
- Pull the seedling + root ball out of the red solo cup (or previous pot).
- (OPTIONAL) Add mycorrhizal fungi to your root ball on every transplant.
- Place the root ball in the new hole and gently press it down.
- Water the pot with 2L of water (½ Ga) if you are transplanting from a solo cup; 4L (1 Ga) if you are transplanting from a 1Ga pot; or 20L (5Ga) if you are transplanting from a 10Ga pot.
Transplanting from a Red Solo Cup into a 3Ga fabric pot
After you transplant and water your plant, it should have enough sustenance for 4 to 7 days until it is time to water it again.
If you are going to transplant one more time in the future, let your plants grow for 2 to 3 weeks in the new pots before checking the roots again. Make sure the roots are growing around the edges of the pot before transplanting again so that they hold your media in place.
And you are done!
Transplanting your cannabis plants can sound like extra work, but it is the best activity you can do in order to grow bigger roots. Don't forget:
Happy roots, happy shoots!