For many cannabis users, the cost of the plant becomes either an unwanted nuisance or at worst, an impenetrable barrier between them and their medication. The cost of growing a cannabis plant is very low indeed. Rather than the inflated £10/$15 per gram prices on the black market, in coffee shops, and sadly even many dispensaries, the actual cost of growing a cannabis plant is closer to just a couple of pounds, even with several plants on a really small scale.
If it were legal then we could have an industrial-scale process which cut the cost down to pennies per gram. Although some would argue that taxation, advertising costs, and pure corporate profiteering would hike up the prices to roughly what we see on the current black market, none of this matters at present as it’s impossible to purchase legally.
So what do we need to grow our own? There are many different methods of growing cannabis, but I’ve found that such an abundance of contrasting and needlessly complex, disparate sources has made it quite boggling for newcomers. With that in mind I’m going to present a single strategy from start to finish, with a few slight variations to help those on a budget or with specific grow space requirements.
First we should talk about the legal implications. Please check that you’re comfortable with the risk (if you live somewhere where it’s illegal), and ensure you know the local laws. In the UK fresh sentencing guidelines were released for cannabis growers at the start of 2012. The most important part of that for most of us is the suggestion that growing 9 or fewer plants constitutes the lowest possible criminal offence, with a likely punishment ranging from a dismissal (no action taken) to a community work order and fine. So long as you aren’t selling or causing a nuisance you can expect to be punished on the more lenient side. This will still mean a criminal record, however.
I recommend The Original Sensible Seed Company as a great source for the best seeds. It’s located within the EU and stocks everything you could possibly want. One problem with seed banks is some can have poor quality control, and you might get old or degraded specimens, so ensure you start off on the right foot with the best possible genetics.
If you wish to check reviews of specific strains, or see a list of which ones produce given effects, some great resources are Medical Jane, SeedFinder, and Leafly. Most stuff by DNA Genetics/Reserva Privada should be top draw, with the likes of CBD Crew creating strains which cater more to the medicinal market. Unless you’re planning on breeding, I recommend buying feminised seeds, as this will save any hassle and wasted energy in growing males which then have to be destroyed.
When it comes time to grow, seeds can be placed in water in the dark, in a warm environment (room temperature or above). Check after 24 hours and tap them to see if they sink to the bottom of the container. If not, repeat every 12 hours until they no longer float. Then transplant them into rockwool cubes.
There are many different configurations possible when it comes to your grow space. Some people like to keep two areas – one with flowering plants and the other with a mother plant, whereas the cleanest way of doing things (in my opinion) is to maintain just a single area, and grow from scratch every time. Unless you are growing for commercial purposes this should yield with sufficient regularity, and it allows you to change to a different strain each time.
The main thing to consider is headroom and the quantity of plants. Especially with taller sativas there can be an issue with vertical space, so ensure that your tent is at least 1.5m tall, unless you are happy growing autoflowering strains or want to use a sea of green or scrog method. For just a single plant you can get away with a 1m (L) x 0.75m (D) tent, but for 3-5 plants you might need that to be 1.5m (L) x 1m (D) x 1.5m (H). Scale as appropriate for your needs.
Rockwool propagation cubes are an excellent item for nurturing your plant through the early stages of growth. There are several sizes, with the idea being that you start with the smallest and add that to a bigger cube once the seedling has had 10-14 days to grow into the initial cube. Before use, it’s wise to soak the cubes in water for 24 hours to ensure they’re sufficiently moist and any ammonia has been released from the water. I recommend the Grodan brand of cube, but most should be fine.
Depending on how many plants you wish to grow, and how automated you want your system, there are a couple of options I’d recommend. The budget option is to go for a deep water culture “oxy” pot. These work perfectly and require very little effort to set-up, but unless you invest in a central reservoir, when dealing with multiple plants it can mean you have to tend to multiple reservoirs each time. For this reason I’d recommend an NFT for people growing 3+ plants. It means there’s just a single nutrient source to replenish, and provides you with more scope for going on holiday/being away from the plants for an extended period. It also makes it easier to avoid the roots getting waterlogged.
This is the area where real choice exists. Those who started growing decades ago have become accustomed to metal halide, CFL, and HPS lights, but I find they introduce all sorts of issues. Firstly, they’re incredibly hot, and generally require significant air conditioning (carbon filters/extraction fans) in order to create a suitable grow environment. Then there’s the issue of heat maps. These days police helicopters come equipped with devices capable of spotting suspicious hot spots, and while this may only be a threat for those with larger operations, it’s definitely an extra point to consider.
There’s also the issue of efficiency and lifespan. The most efficient means of providing light for your plants is the use of an LED panel. Not only will your electricity bill shrink beyond belief, but the lights themselves can last for up to 100,000 hours, which is translated into 10-15 years of constant growing. LED panels mostly use the colour spectra which best benefits the plants – almost entirely eliminating white and green light. This means we really maximise our watts.
The downside of LED panels is the initial outlay. You can buy very cheap models from China on eBay, but they will do a terrible job and be cast aside after a single use. Then we have mid-range panels which do a pretty good job, but can’t compare to a CFL/HPS in terms of wattage and depth of penetration. It’s for that reason that I’d recommend one of the high-end models such as the Pro Grow LED 300w panel, from Hydroponics Hut (EU link / rest of world link). They provide extra power due to the 5w bulbs used (as opposed to older 3w or even 1w models), and do a great job compared to most other models. One is suitable for excellent coverage of a 1m x 1m space.
For those on a budget I would suggest going for the 180w Pro Grow model from a few years back (EU link / rest of world link), but I can’t stress enough how much better the 300w panel performs. Although $750 sounds a large sum of money, just growing a single plant could potentially yield a couple of ounces, which means the LED panel pays for itself in a matter of months, and then you effectively have it for free for an entire 15 years. And if you really must purchase a traditional bulb, you can read up on them here and here.
An important tip to note is the position of the lights, and the intensity. By careful placement we can ensure the plants receive an optimum level of light. For instance, if we had several smaller-watt bulbs positioned closer to our plants, it would be more effective than a greater amount of watts being emitted by a single source, from a greater height (due to the extra heat produced). See the following diagram for a complete explanation. Remember that for LED lighting it’s good to have at least an 8″-16″ gap. For traditional bulbs this distance should be significantly larger.
Perhaps it’s the lack of industrial, overheated lamps in the grow area, but the need for a carbon filter and air extraction unit seems to have passed some by. Fair enough, you may need it if you’re using a basement with 100 plants, but if your room has a window with nobody likely to pass right outside, that’s good enough. What about the smell? Well, there’s a wonderful item called the Ona Block Pro, which neutralises anything you can throw at it. Just wait until a few weeks into flowering (they tend not to smell until this point) and put one of these inside your tent. You can have the lid slightly open, or fully off, depending on the level you require.
They last for 4-8 weeks each and mask odour perfectly. To extend their life once efficacy drops, you can typically cut them in half, poke holes through them, or even turn the block upside-down, and they’ll last even longer. On top of this it’s worth buying a few plug-in air fresheners which automatically release fragrance. Depending on your layout, you might have one in the room where you’ve got the tent, and another next to your front door.
Nutrients form a vital part of cannabis cultivation. There are entire ranges available from the likes of Canna, but many growers will tell you that it’s purely the vegetative and flowering (Aqua Vega, Aqua Flores) nutrients they use, perhaps with a touch of molasses in place of the ‘bloom’ booster which is added nearer the end of the grow cycle. Handily, Canna and Growell produced a PDF guide which details the appropriate feeding schedule for the duration of the plant’s life.
As with the soaking of rockwool cubes, when mixing nutrient solution it’s best to use tap water which has stood for 24 hours. Then add your nutrients to the solution before balancing the pH using an electronic pH meter. No matter which you buy they have a very short lifespan, so I recommend buying a relatively cheap option. For most cannabis plants, a pH of between 5.8-6.0 is considered optimal.
Remember that the schedule is based on a 9-week flowering cycle. Check the flowering time for the seeds you’ve bought and if necessary, add extra weeks which extend the middle of the cycle.
Cultivation – Seedlings
To help seeds pop, once you’ve put them into rockwool you should use a heated propagation dome in order to maintain a warm, moist environment. If your climate is very humid you may find that they can go straight into the hydro system, although I think it’s good to give them a week or so in the propagator just to smooth their progress. Don’t feed them any nutrients at this point – simply ensure the rockwool is kept damp with water. If you notice the seedlings are stretching too tall, ensure they’re placed somewhere with better access to light. From seed to harvest, we want the temperature to be around 25c degrees (77 fahrenheit). Make sure you use a digital temperature/humidity device to help accurately monitor grow room conditions at all times.
Cultivation – Vegetative Growth
Once they’ve been added in your hydro system you’ll need to wait around 4 weeks with the lights lit 18 hours per day, on a timer for precision. The water/air pump should be running for as much of the time as possible, as should a fan. It’s important not to have the fan on too ferociously at this stage as the plants will still be weak. We’re looking for air circulation above all.
It’s key to prune your plants once they’ve acquired several sets of leaves. Anything which is unlikely to get much light should be removed, with the focus being on the tops of the branches, rather than potential bud sites all the way along. Look to ensure no more than the top 5 sets of leaves of a branch are maintained. Snip off any unwanted foliage and dead (significantly browning/dry) leaves using pruning scissors. If you wish to produce shorter, stockier plants, look into topping them. This link also gives an excellent explanation of pruning theory in general.
Cultivation – Flowering
After 3-4 weeks of vegging under 18 hours of light, and 6 hours of darkness, we want to set the plants into flowering mode. This is done by simply adjusting the lights to be on for 12 hours, and off for 12 hours, each and every day. Also, we want to change the nutrient supply to match the minerals required to produce big buds. If you’ve gone the NFT route, one trick for emptying the reservoir is to put a hose/pipe onto your water pump and have it empty into a container.
In order to get every last bit out, you can place a couple of items underneath one end of the tank, and the water will rush down towards the other. Shoe boxes or bricks work perfectly well for this task. It’s recommended that you change the water at least every two weeks, in accordance with the nutrient dilution shown above.
Cultivation – Harvest & Curing
Usually after 9-15 weeks of flowering your plants will be ready to harvest. As a guide, we want just over 50% of the trichomes to have turned amber in colour, else the bud won’t have full potency. See this guide for more information on spotting the perfect time to chop your plants. For the last 7 days we only want to feed our plants pure, un-pHed water, so as to flush the existing nutrients out and get a better flavour. Once they are ready, carefully cut the branches away so you have small, manageable pieces to work with. We want to keep buds on the stem whilst they are drying (not a huge stem, just the adjacent few inches), as this facilitates the curing/drying process.
Trim leaves off as close to the bud as you can, without damaging the actual flower. It’s fine to have the small, immediate leaves left on. Once you’ve finished manicuring your plants, you need to give them about 5-7 days drying time, preferably somewhere that’s room temperature with good ventilation and no light. We don’t want anything too hot or too breezy, as fast-drying tends to lessen the quality and flavour of the cannabis. An ideal solution is to use a drying net, which can be hung anywhere.
Once the branches are almost to the point where you can snap them, that means they’re dry enough and you can move everything to mason jars. For the first couple of weeks we want to keep these completely sealed, aside from an hour a day when we lay the contents out on a plate to let excess moisture escape. After a fortnight the frequency of this airing process can be reduced to 15 minutes every other day. If you find that the buds are still wet, leave them out for a longer period. We really want to avoid mould caused by damp, as that will completely write-off your weed.
You can use your cannabis at any point after this, but the longer you leave it to cure, the better the flavour, the smoother the smoke, and the more developed the cannabinoid content. Some people can leave their plants to cure for over a year before using them, but that’s not an easy task unless you have another stash.
Shopping List & Summary
Here are the items you’ll need if you follow my guide. I’ve linked to things I’d personally recommend, from sellers with good reputations. If they’re not available in your region simply perform a search for the product on a local vendor’s site.
- NFT or DWC Oxy-pot
- Spreader mat for NFT
- LED panel – EU / Rest of World (or a traditional bulb kit)
- Suitable cooling and ventilation
- Light hanger
- Vegetative and flowering nutrients (at a minimum – refer to Canna chart for other possible nutrients)
- Grow tent / another
- Growing cubes & transplanting cubes
- Drying net
- Ona Block Pro deodoriser
- Plug-in air freshener
- pH meter & pH balancing solution
- Heated propagator
- Temperature and humidity meter
- Power extension strip
- Pruning scissors
- Pipette – for the pH balance solution
And here are some quick tips worth remembering:
- Heat, light, and fresh air will degrade your finished product – avoid them if possible
- Always buy a spare of anything that’s absolutely vital
- Don’t tell anybody you don’t trust 100%, and even then…
- Beware of strangers, landlords, or unexpected visitors – always have a preprepared excuse why somebody can’t go in ‘that’ room
- Don’t get caught smoking weed – vaporising can ensure there’s nothing for the neighbours to smell
Do you have any further questions? Then please feel free to visit my Facebook and Twitter pages, and ask the community for help. It’s really not a difficult process, but as with everything it takes some getting used to. What are you waiting for? Cheap, top quality toking awaits!
If you liked this guide, you might like some of the other guides on the website. There are a number of videos detailing much of what’s discussed in this article.
Do you have any suggestions of items you'd like reviewed? Indeed, if you'd like your own products reviewed (strains, weed seeds, grow gear, smoking devices, vapes etc.) please get in touch via the Contact Us section or the Facebook Page.