best light for starting cannibus seeds

The complete guide to germinating cannabis seeds

Before you can be met with bountiful hauls of dank buds, there are several stages of cannabis growing that take precedence. Unless you can successfully germinate cannabis seeds, you won’t have a plant to harvest. Give your seeds the best possible start in life by reading our definitive guide to germination.



Often overlooked, it is all too easy to assume that the vegetative and flowering stages of cannabis growth are the most critical parts of the plant’s life cycle. However, with the chance of failure high unless you know what you’re doing, poor planning when it comes to germination can make or break your next grow. Giving your cannabis seeds the best possible start on their journey to bulging buds is a surefire way to encourage a healthy and robust plant.

Small, fragile, and in desperate need of a helping hand, there are several ways you can germinate your cannabis seeds. All methods have varying degrees of success, with both advantages and disadvantages. It is important to note that even with advanced growing expertise and top-of-the-line equipment, you may still end up with a few failed seeds. This is a natural part of dealing with a living organism. At Royal Queen seeds, we only sell feminized cannabis seeds, so there is no need to worry about removing male plants.


Regardless of where you get your seeds from, it is best to give them a slight (and delicate) inspection before planting. Most of the time, all seeds will germinate; however, poor-quality seeds will produce a weaker plant. Unfortunately, that is something you will not find out until well into the vegetative and flowering stages.

To avoid disappointment, seeds that have a darker colouration stand a better chance of germinating, while pale green or white seeds are likely to fail. Even if dark seeds look slightly damaged, they should be planted anyway. There is a good chance they will still germinate, even if the outer shell is somewhat crushed.


Before we jump straight into the germination methods, there are a couple of germination golden rules. For the best results, we recommend staying within these guidelines, no matter how you choose to germinate. That being said, of all the factors to consider, temperature is one of the most critical. Seeds will always seek out even the smallest amount of moisture, but they use temperature as a sign that they need to do so.

• The ideal temperature is between 22° and 25°C (71–77°F)
• Your growing environment should be damp/moist, but never wet
• Relative humidity range should be between 70% and 90%
• Seeds favour fluorescent lighting (Cool White code 33)
• Minimise the amount of seed handling you do
• In hydroponic/rockwool plugs, the ideal PH value is 5.8–6.2


Three fundamental principles will trigger that first small taproot to appear: warmth, moisture, and darkness. With the promise of moisture, a single root will take shape before slowly developing into the cannabis plant we know and love. In the right conditions, seeds will begin to develop within 12–36 hours of moisture being introduced to them.

Timescales can vary, as it all depends on how ideal your germination environment is (see the golden rules above). Even the worst grower could make a seed germinate, but it may take a few weeks and, of course, increases the risk of a weaker plant.



Arguably one of the least effective methods, but it is still viable. Incredibly simple to facilitate, beginner growers may opt to germinate their seeds in a glass of water. Half-fill a glass or bowl with water that is approximately 22°C (71°F).

After 3–5 days, the seeds will start to open, and you should see tiny white tips appear. Once these roots reach 2–3mm in length, use extreme care to transfer them from the water to pre-prepared soil pots.

The soil pots will need small holes (roughly 10–15mm deep) for the newly germinated seeds to be placed into. Once the seeds are secure, you will want to place a fluorescent light 13–15cm (5–6 inches) away to encourage growth. Finally, don’t risk overwatering your seeds at this early stage. Use a plant mister to make sure they stay damp but not soaking wet.


Probably one of the most common methods of germination. The kitchen towel method comes in several iterations. Some growers use cotton wool pads or absorbent pieces of paper. For this guide, we will be using kitchen towel as it is readily available and holds moisture relatively well.

Place one sheet of damp kitchen towel on a flat surface. Space your seeds a few centimetres apart before placing the second piece of kitchen towel over the top. You need to ensure both pieces are damp, not wet. Once again, when the white root tips reach 2–3mm, move the seeds (carefully) to soil pots. Use the same guidance found above for planting techniques.


Planting directly into your growing medium prevents having to move seeds when they are at their most fragile. That first root tip is covered with microscopic filaments that are easily damaged. Given that both a cup full of water and moist paper towels are more prone to temperature fluctuations from their environment, planting in soil is a much safer option.

Start by filling pots with a premium-quality soil that has been soaked in water. Many growers also choose to lace the water with a root stimulator. Make a hole roughly 10–15mm deep. This will be your seed’s new home. Remove the seeds from their packet and place them into the pre-dug holes. Loosely cover the seeds, but be careful not to compress the soil above the seed too much. The root will struggle to penetrate solid soil, slowing plant growth. Lightly spray the top of where you placed the seed so that your growing medium stays moist.

If you don’t like the idea of pre-soaking your soil, you can use a spray to moisten the holes before you plant each seed. With enough moisture surrounding your seeds, you can still encourage a root to develop.

Your growing pots will need to be placed in a damp climate that is within the temperature range listed under our golden rules. After 4–10 days, you should see a young seedling sprout, while the roots will have begun to develop underneath the soil. The entire plant and its soil can now be transferred to a larger pot, where normal growing routines should start.


Maintaining the ideal temperature (between 22–25°C/71–77°F) and moisture for germination is tricky. Leaving seeds out in the open environment or on a windowsill is far from ideal; a DIY climate-controlled cupboard would do a much better service. A warming mat is perfect for maintaining a constant temperature, but it doesn’t tackle the issue of moisture.

You will need to invest in a few pieces of unique equipment, but by using stone wool blocks, you can create a perfect utopia for germinating cannabis seeds. Soak the stone wool blocks in the same way you would a soil medium. The wool will retain the moisture and prevent the need to water during the early stages of germination. After the wool blocks are soaked, stick them in a plastic tray that also has a lid. Large cake tubs are ideal.

The dome of the plastic container will create your seeds’ own mini tropical climate. If you then place all the components in a temperature-controlled cupboard, you will have created a self-perpetuating supply of moisture—no need to touch the seeds again until they are ready to be transferred to your final growing medium as a young seedling. Using the stone wool block method, your seeds should germinate in one to two days.

Two or three weeks after germination, your young seedlings should be ready for their new home. At this point you have two options; transplanting them into soil pots, or taking on the challenge of hydroponics. You’ll know when the seedlings are ready to be moved because the root system should start to poke out of the bottom of the wool blocks. As long as the roots haven’t begun to engulf the bottom half of the wool block, they will seek out water and nutrients in their new surroundings and continue to grow downwards.


There is, of course, a far simpler way to germinate seeds. Ideal for beginners, the feminized starter kit by Royal Queen Seeds has everything you need to kick-start your next cannabis project.

The Royal Queen Seeds Feminized Starter Kit contains:

  • 3x RQS Critical feminized seeds
  • 20x Easy-Start seedling pots
  • 1x Propagator Pro
  • 1x pack of Bacto
  • 1x perlite
  • 1x fluorescent lights
  • 1x instruction manual
  • 4x AA batteries
  • 1x Royal Queen Seeds catalogue

*You will also need a measuring cup and a stirrer (not included in the kit).

1. Gently remove the foil from the back of the seed packet and place them carefully into a dry container.

2. You will need a shallow container that is large enough to accommodate the seed tray. Fill the container with one litre of lukewarm water (22–25°C/71–77°F). Pour in the packet of Bacto enzyme, allowing it to dissolve before setting the seed tray into the container to soak. The seed tray only needs to be immersed for 5–10 seconds. Do not discard the Bacto mixture after the seed tray has been soaked.

3. After removing the seed tray from your shallow container, poke a 10–15mm deep hole into the soil of each pot, and delicately transfer your seeds from their dry container into each hole. Remember, one seed per pot.

4. Using the supplied propagator, sprinkle a 15mm-thick layer of perlite into the bottom of the tray.

5. Place your seed tray into the propagator, adjust the walls, and position the lid. The lid comes with an on/off switch for the already-attached lights.

6. Check the water level in your reservoir once a day. Your aim is to maintain an even level. After 1–7 days, the seeds should have sprouted, with visible leaves appearing. Once the seedling is 3mm tall, transfer it to your final growing medium.


No matter which method you choose, always think about what conditions would naturally be like in spring. In their natural environment, cannabis seeds would start to sprout in-line with the seasonal change from winter to spring. Moisture is still high, and temperatures will be naturally rising. Always ask yourself the question, “Does my germination setup replicate spring conditions”. If the answer is yes, there is a good chance germination will be a success.


In most cases, germination will go off without a hitch. However, there are a few troubleshooting issues we can help with.


The first is lighting. Your seed/young seedling will only need fluorescent or CFL grow lights, at least to begin with. While plants need light to thrive, too much of a good thing will damage cannabis in its first few weeks.

Position lights about 15cm from seeds. Once your seedling has developed its first proper leaves (they will have jagged edges), you can move the lights as close as 5cm. If you are concerned about damaging your seedling, place your hand between the leaves and your lights. If you cannot hold your hand in place for ten seconds without it being too hot, move the lights 2cm away. Repeat until you are comfortable with the temperature.

As young seedlings grow quite quickly, you will need to keep adjusting lights to get the best results. After two weeks under fluorescent lights, you will be able to switch to high-powered HPS or MH-style grow lights.


Don’t panic, where possible roots will always grow downwards. It is not necessary to try and reposition the seed yourself. Disturbing the seed at this crucial time will do more damage than good. In most scenarios, what you are actually seeing is not a root protruding from the top of the seed, but the stem of a cannabis plant.

If you are ever unsure, always wait a few days for the first leaves (cotyledons) to appear. As long as a seed’s requirements have been met, the seedling should sort itself out. The best approach is not to panic; follow the golden rules and your young seedling will be ready to transfer to a larger pot in no time.



It will depend on the growing medium you are using, but in most cases, you will not need to supply any nutrients for the first 2–3 weeks. There will be of plenty of nutrients available in the soil, and even coco will only need nutrients added after a week or so. If you do opt for coco or hydroponics, nutrients should be added at 0.25x their regular strength. Once the first set of leaves appear, increase this in increments of 0.25 per set of leaves. For beginners, we would always recommend using a soil medium. It allows you to get to know the intricacies of growing cannabis more efficiently, and can be the least punishing if you make mistakes.

An easy way to spot if more nutrients are needed is to observe the leaves. The serrated leaves will start to turn pale green as nutrient stores are depleted. Left long enough, leaves will eventually turn yellow. This is a definite sign that more nutrients are needed. Your plant will not die if the leaves turn yellow, but it is a timely reminder to feed your young seedling.

Nitrogen is the most commonly needed nutrient during periods of high growth. Once the seedling has been fed, the colour of the leaves will return to normal. Depending on how long you waited to take action, this can take a few hours or a whole day.


The first few weeks of a seedling’s development require very little interference. Nutrients, as we have mentioned, will need minor tweaks, as will lighting. However, now that your seed has germinated, you have a few weeks of grace. Sit back, relax, and enjoy your cannabis plant taking shape.

Once those initial weeks have passed, you can treat your seedling like it is in the vegetative stage, and switch to strict lighting routines and full-intensity light. During germination, always remember the golden rules, and if in doubt, ask yourself if you have created “springtime conditions”. If you are confident everything is on track, all you need to do is observe and marvel at the creation of your very own cannabis plant.

Royal Queen Seeds Produces Some Of Europe’s Best Cannabis Seeds, Ensuring Hobby Growers Everywhere Have Access To The Finest Marijuana Strains Around.

Royal Queen Seeds Produces Some Of Europe’s Best Cannabis Seeds, Ensuring Hobby Growers Everywhere Have Access To The Finest Marijuana Strains Around.

Part. 2: The Vegetative Phase. The germinated seeds peak out above ground and immediately spring up.

Part. 3: The Cannabis Blooming Phase. Just another couple of months of blossoming we will be ready to get our sheers out of the cupboard.

Part. 4: The last weeks of flowering stage. After weeks of mounting excitement the long-awaited moment the harvest is finally within arm’s reach.

Part. 5: Harvest Time. Learn every step of the cannabis harvest and post-harvest process.

Time then to whip out our packages of seeds and get to work. But how do you best set to work, to get these tiny, fragile seeds to grow without problems into small plants?

Best lighting for growing cannabis

Lighting types, schedules, and electrical money-saving tricks—you will be amazed at how much you can use lighting to your advantage in the cannabis grow-op.


As you progress in your journey toward becoming a grandmaster grower, you will soon start identifying the limiting factors in achieving those glorious yields we all love to see in photos and videos.

Inarguably, lighting is one of the biggest and most immediately recognisable of such limiting factors. Within reason, the more light you give your plants, the more they will yield.

Other valuable aspects of growing include environmental conditions like CO₂ levels, maximum and minimum day/night temperature, and relative humidity range. Nutrition is also of equal importance. Feeding needs to be adjusted to what the plant is asking for based on its phase in the grow cycle. Some growers even go the extra mile and have classical music or biowaves playing to stimulate the stomata to squeeze in a little extra growth spurt. However, the jury’s out on whether this yields any noticeable results—but it can’t hurt!

Light is, in itself, just another type of “food” for plants. Keeping this in mind will allow you to better decide what is right for you. Just like an athlete has a specific dietary regime for his sport, so must you consider what is the ideal type of light for your growing conditions.

There is little point in blasting your cannabis plants with 2000W/m² if you are just getting started, or deciding on the latest and greatest LED fixture if you cannot dial in the right ambient temperatures. Plant height and spatial limitations also play very important roles depending on which type of lights you decide on.

In this article, we will give you rundown on what constitutes the “best” light for growing cannabis. There are many pros and cons to each, and a little information goes a long way.


In the beginning, there was light…from the sun! Then cannabis became illegal, and someone had the brilliant idea to bring a powerful street lamp indoors to simulate the sun and grow weed.

Not only did this work, but it also created a massive industry catering to indoor/greenhouse operations. This lighting technology is called high-intensity discharge, or HID. Typically, these lights come in one of two varieties, either sodium or metal halide. These lights are very strong, quite inefficient, and produce a substantial amount of heat. But if you manage to tame the heat, they get the job done fantastically well.

Primarily due to space constraints, some growers started experimenting with lower-powered and more efficient lights. More efficient means less electricity is lost to heat, and more of it transformed into actual light. For instance, CFLs—compact fluorescent lights—are quite efficient, small and compact, cheap, and readily found in any common hardware store or supermarket. Ideal for seedlings and clones, they underperform for flowering. This is due to the limited light spectrum they produce. On the other hand, you will be able to fit a few of them inside a covert, desktop PC micro-grow retrofit.

In recent years, we have witnessed the beginning of a new artificial agro-specific lighting era. Modern LED fixtures are superbly efficient, while at the same time producing a great PAR, which means photosynthetic active radiation. This is the measure of the quality and intensity of the light spectrum that the plants actually use for photosynthesis. This in and of itself does not necessarily mean LED is better than HID or CFL—it just means it fills a huge gap really well.

A special mention to plasma fixtures. While operating under the same principles of HIDs, they do have a better spectrum than sodium or metal halide bulbs.


Light schedule is something quite often overlooked. Some growers take years to realise they can further manipulate their plant’s behavior in their favour, with simple light schedule tricks.

The typical schedule will be something like 18 hours on and 6 hours off during the vegetative period, and a flat 12–12 for flowering.

But did you know you can do so much more? You can save significant amounts of electricity if you employ the gas lantern routine during the vegetative period, while maintaining a high level of performance.

Giving your cannabis plants 24 hours of darkness before switching to flowering is known to induce sexing substantially faster in many strains.

During flowering, if you progressively decrease the lights-on period, you will trigger the plant to speed up production. This can be done by setting your timer to turn off 10 minutes earlier each week until harvest. This will simulate the natural shortening of days as autumn sets in while saving you a little extra on electricity.

This technique is sometimes referred to as light deprivation or the diminishing light technique.

Some growers swear by a 10–10 flowering schedule. The theory is that you will trick the cannabis plant into shorter day cycles. You can fit 8.4 “short days” in each week. That means that a typical 9-week strain (63 days) can be ready in 7.5 weeks (52.3 days).

Even autoflowers can benefit from experimentation, so do not be shy to try it out for yourself.


Even if electricity were free, getting into a habit of saving electricity will not only be an environmentally conscientious thing to do, it will further improve your skills. Understanding and measuring your environment will save you time and money while improving the potential of your plants.

Investing in an automated exhaust system works wonders to save on heating. In the winter, exhaust fans will blow slower, thus conserving heat. Mid-summer, they can work full-power to keep things under control. Many modern inline–exhaust fans come already pre-built with heat sensors for this very purpose.

This can be done cheaper by manually using a quality variac transformer. These will slow your fans down while prolonging their life. Do not confuse variacs with typical dimmers, as these will create a noticeable hum and take a heavy toll on your gear.

If you use butane/propane heaters to warm up your house, slowing down the fans will not only help conserve heat, but will have a dramatic effect on the available CO₂, which will boost production potential considerably. Higher CO₂ levels also mean you can run the grow room at higher temperatures, so it is a win-win situation.

If using LEDs, you can lower the lights closer to the canopy without burning the leaves or buds. You’ll notice you will be using fewer nutrients and water while your girls flourish considerably better.


There are dozens of little tricks to boost yields and save on productions costs. From training, stressing, environmental manipulation, and of course, lighting. But there are no silver bullets.

There is a reason experienced growers swear by one method over another, or one type of light over the next. Even the biggest commercial operations have radically different approaches.

Different genetics, different growing mediums, different growers—this is a never-ending debate. And thankfully so, as it keeps us on our toes and on top of our game in pursuit of top-quality buds.

Remember that what works for one person may be a complete flop for the next. Experiment slowly and gradually introduce the next features—never make rash decisions. This way, you will be able to judge what works and what doesn’t for your operation. Also, be sure to take notes and pictures so you can track your progress.

As you improve and create a deep relationship with your secret garden, you will certainly reap the rewards of the efforts you put into it.

Traditionally, most cannabis requires long days of full sun to produce its full potential of luscious bud harvest.