by Nebula Haze
Table of Contents
- No-Move Germination – Plant seeds directly in final pot.
- 18/6 Light Schedule – Set timer to 18/6 ON/OFF
- Water Seedlings Right – In a small circle every 2-3 days
- Perfect Environment – Like a warm Spring day
- Measure Your Success – How big to expect seedlings to be
Bonus: 7 Recommended Seeds for a Strong Start
How to Start Strong: Fast-Growing Cannabis Seedlings
Many cannabis growers struggle with seed germination and seedling care. That’s normal! But cannabis germination and happy seedlings are easy with the right techniques.
Give cannabis a great grow light, like this TSL2000 LED (8-14 oz yield – learn more)
Here’s how to get seedlings to grow: Follow the steps in this “fast start” seedling tutorial. Your cannabis seedlings will grow so fast that other growers won’t believe how big they are for their age.
These cannabis plants are just 1 month from germination. They got off to an ultra-strong start using the techniques in this tutorial.
Starting strong is an important aspect of achieving big yields with cannabis. Especially autoflower strains, which have an extra short seedling period, and start flowering (making buds) in just a month from germination. That means a slow start results in small autoflower cannabis plants that stop growing bigger when they only have a few bud sites.
No matter what you do, a tiny stunted plant can not compete on yields with a big cannabis plant with tons of bud sites positioned directly under the grow light.
1.) Germination – Plant Directly in Soil
My recommended germination method for a fast start is to plant the seed directly in the coco or soil. This way you never have to move your seedlings after they sprout.
Plant your cannabis seeds and keep them warm during germination. Warmth is key to fast, strong seed germination.
2.) Light Schedule – 18/6 ON/OFF
My recommended light schedule for seedlings is 18 hours light/day. You can give cannabis plants up to 24 hours of light a day, but giving a 6-hour night increases the overall hardiness of seedlings vs giving them no dark period.
Use a cheap electrical timer to turn your grow lights on and off for you. Set it to turn the lights off for 6 hours a day. Perfect for cannabis seedlings.
Give seedlings 18 hours of light a day by putting grow light on a timer.
Use a cheap electrical timer to turn your grow lights on and off for you. Set it to turn the lights off for 6 hours a day. Perfect for cannabis seedlings.
Just plug your grow light into the timer, and the timer into an electrical outlet. Now you’re good to go! The timer turns the lights on and off for you on the 18/6 schedule.
3.) Watering Seedlings – In a small circle around the base, every 2-3 days
The easiest way to stunt autoflowering seedlings is from poor watering. Give them the right amount of water (not too much, not too little) so they’re growing fast right out of the gate.
Give just a little water at a time in a small circle around the base of new seedlings at first. Water every 2-3 days.
4.) Environment – Like a warm Spring day
Analogy: Seedlings are kind of like the story of the 3 bears. Just like Goldilocks, seeds want the temperature just right. Not too cold, not too hot.
Ideal Environment for Seedlings
- Warm – 80-85°F / 27-30°C is a lovely warm-but-not-too-hot temperature range for new seedlings and young cannabis plants.
- Medium-high humidity – 50-65% RH is a good humidity range after the seedlings have popped their heads above the soil. Too low humidity and seedlings get stressed. Too high humidity and seedlings don’t grow as fast as they could because their leaves can’t transpire as much.
- Breezy – Make sure plants have fresh air, plus a gentle breeze to strengthen stems and help prevent the possibility of mold or stem rot.
5.) Measure Your Success – How big to expect seedlings to be.
Aim for 6 sets of new leaves by day 21 from germination.
If plants have grown at least 6 sets of leaves in 3 weeks (day 21) from germination, you’re perfectly on track. If plants have fewer leaves than that, it’s okay, but you may still have room to improve your start.
For photoperiod plants, a slow start isn’t a big deal; it just means you may need an extra week or two in the vegetative stage. However, for autoflowering plants on a tight schedule, slow start plants may not get as big or produce as much weed as they could have.
An average “strong start” looks like this. These cannabis plants are 21 days from germination. Some are bigger than others, but overall they’re all growing fast and healthy. Even the smallest one has 6 sets of leaves (though the 6th set has just started growing in on that upper right plant).
In perfect conditions, with fast-growing strains and a strong grow light, cannabis plants can get even bigger in that time. These autoflowering plants are also just 21 days from germination. Now that’s a STRONG start. I think this is the biggest I’ve ever seen seedlings get in that time period. Note: They were grown under an 4000k LEC/CMH grow light, which tends to get faster vegetative growth than other grow lights, in my experience.
Cannabis plants depend on you for a strong start.
For photoperiod plants, a strong start can shave a week or two off your total grow time, which is awesome.
For autoflowering plants (which start making buds when they’re about a month old on average), a strong start is key to getting good yields. If autoflowering plants start making buds before they reach a good size, they’ll stay stunted and puny, incapable of producing a big harvest. That means it increases your yields to avoid common pitfalls that slow down young plants.
By germinating seeds in their final destination, giving 18 hours of light a day, watering seedlings perfectly, and giving a perfect environment, you’ll get strong fast-growing seedlings that get big quickly and can start flowering as soon as possible to produce a big harvest.
Give great care to your cannabis plants and they reward you well!
Bonus: Recommended Seeds for a Strong Start
Standard Strains (Photoperiod) – These are my top 3 personal favorite strains right now.
- Candy Games #38 – Good germination, outstanding density and bud appearance. May be one of the most potent strains on the market, testing at over 30% THC. Smells amazing. Grows hard “nugs” of weed that are easy to dry.
- Mandarin Cookies V2 – I absolutely love the buds from this strain, including the appearance, but especially the effects. Buds are potent, relaxing and smell of pineapple and sweet to me. Produces stellar bud quality even if you make some mistakes. Absolutely encrusted in trichomes, and tests particularly high in relaxing limonene.
- Purple Ghost Candy – This strain is extremely easy to grow with massive yields and some of the best bud quality I’ve grown. Plants get big, and grow fast. Make sure to initiate 12/12 once plants reach half the final desired size. Responds extremely well to training. Will reward you with enormous yields, just make sure to give plenty of light and nutrients.
Four different examples of Mandarin Cookies V2 I’ve grown in different environments. Forgiving plants, and always an outstanding smoke.
And an example of the resulting Mandarin Cookies V2 buds after harvest. Like out of High Times magazine 🙂
Autoflowering Strains
- Banana Daddy Auto RBX2 – very potent but still relaxing effects (described as “euphoric) that may be a good choice for those with anxiety who still want to get high, with around 24% THC and 1-2% CBD. About 80 days from germination to harvest. Chunky buds and the plant stays a manageable height.
- Blue Dream Auto – Ready in as little as 62 days though THC improves over another 1-2 weeks, dense buds, low CBD to help the buds feel more potent.
- Creme de la Chem Auto – A personal favorite, ready in 65-75 days (mine was ready in 70). I love the bud effects, which feel strong yet mellow and relaxing.
Bonus: Pineapple Express Auto – One of the most famous auto-flowering strains of all time, this is ready to harvest in under 70 days from germination.
This Creme de la Chem Auto grown under a tiny LED turned into a bud ball.
