Growing Cannabis As Fast As Possible: What You Need To Know

There are plenty of reasons you might want to harvest early. Perhaps you're moving house and have to pack up your grow room, or you grow outdoors in a northern country where the autumns are short, cold, and brutal. Perhaps you're low on weed and hate to fork over your hard-earned cash in exchange for your meds. Maybe you live in a not-so-cannabis-friendly place and you think LEO is onto you.

No matter the reason, there are proven ways to rush things along, whether you're growing inside or out. Still, you might have to compromise yield and potency in exchange for speed. Let's take a look at what you can do to grow cannabis as fast as possible.

Tips For Faster Indoor Grows

Growing indoors is almost always faster than growing outdoors, mostly because you can control the lighting. You can tweak a few other things in the name of speed too.

1. Grow Autoflowering Cannabis

As a general rule, autoflowering cannabis will mature at a faster rate than photoperiod strains because they contain a percentage of ruderalis genetics. Ruderalis evolved naturally in cold places like Siberia where the summers are very short. They had to develop the ability to produce flowers and seeds quickly to ensure the survival of the species.

Most autoflowering hybrids will start to flower two weeks after germination, and can be harvested about 7 weeks later. Quick One, for example, completes its full life cycle in 8 weeks and still yields up to 150g/plant.

Note that breeders are now reducing the amount of ruderalis they use to create autoflowering hybrids in order to increase yield and potency. As a result, some may take a little longer to be harvest-ready, or require a 20/4 or 18/6 light cycle for flowering.

2. Take Photoperiod Strains Straight To Flower

You can force photoperiod strains to mature almost as fast as autoflowering cannabis by putting them in 12 hours of darkness every day from the time they germinate. It works, but your plants will not get nearly as big or yield as much as if you had allowed them to veg for the normal 4–6 weeks.

If you want to use this method, you can start with either clones or seeds, but you'll need to grow a lot of them in sea of green (SOG) fashion if you want enough herb to hold you over to your next harvest. Most plants will be dwarf-sized and only yield 28g or less each.

3. Grow From Clones

Growing marijuana clones is a surefire way to speed up the growing process. A cutting acts as a sort of mature seedling, ready to enter the vegetative stage. Although it may take a little time for your cutting to put down new roots, this is significantly shorted compared to the time it takes for a seed to germinate and complete the seedling phase. Growing clones indoors makes for a simple, quick alternative to germinating seeds every time.

If you’ve already got a grow on the go, and you’re happy with the plants in there, you can continually take cuttings from your plants to begin the next grow. This method is both fast and gives you consistent plants to work with. If you don’t already have plants growing, sourcing clones can be very difficult, unless you have friends who also grow.

Note: We recommended against cloning autoflowering strains because cuttings retain the age of the host plant and will flower before they reach a suitable size.

4. Veg With Lights On 24 Hours A Day

This is a hotly debated topic, but you can leave your lights on 24/7 and your cannabis plants will be just fine. Unlike some other plants, they don't need a dark period each day to be healthy. In fact, they'll stay shorter, grow faster, and get bushier under a continuous light period.

By keeping the lights on all the time, you may be able to cut your veg time by a third and still have a good-sized plant by the time you start a forced bloom. If you try this technique, keep a close watch for deficiencies. If your plants look like they're getting sick, reduce the wattage or hours of light to help them recover.

5. Give Your Plants Less Than 12 Hours Of Light Per Day During Bloom

If you'd like to jump-start the flowering process, put your plants in complete darkness for 48 hours before you start the 12/12 light cycle. Then, use a 11/13 light cycle throughout bloom. The extra reduction will trick your plants into thinking winter is rapidly approaching.

Starving a plant that wants to bloom for 9–10 weeks to force an early harvest can have a negative impact on yield. If you're going to try this method, choose a cannabis seed with a naturally short finish time like Honey Cream. This is a high-yielding indica that only needs 6–7 weeks to complete its flowering cycle.

6. Consider Switching To Hydro

Compared to soil or a soilless mix, hydro can reduce your veg time by a few weeks. This method delivers nutrients directly to the plant's roots so that they practically grow right before your eyes. It won't make the flowering period go much faster, but hydro usually produces heavier, denser buds and bigger yields. You might decide that, in this case, the time was well spent.

7. Proper Nutrition Helps… A Lot

Sick plants need time to recover, so every time you overfeed, underfeed, or feed the wrong thing, you're stretching the time until harvest. If you're using nutrients designed for cannabis, they should come with instructions that tell you how much of what to use, and when to use it. Follow the directions, but keep the mix on the light side until you know if your plants are nutrient-sensitive.

Cannabis needs more nitrogen (N) when vegging and more phosphorus and potassium (P & K) while flowering. If you give then too much nitrogen during bloom, it'll slow down bud growth and result in lower yields of fluffier buds. That's the exact opposite of what you want!

8. Perpetual Harvest — Use Different Rooms

If you have the luxury of space and capital, getting a perpetual grow schedule going means you'll have a very regular supply of bud. At its most simple, perpetual growing involves dedicating one space to plants that are in the flowering stage, and another to plants that are vegging. At least two separate spaces are essential, as photoperiod plants require different light schedules, and ideally different light spectrums, depending on which stage they are in.

Once plants are ready to flower, you move them into the flowering space. From there, you can immediately germinate and begin vegging a new crop, ready to start flowering as soon as the old crop has been harvested. Then you repeat!

The more available spaces you have, the more regularly you can achieve a harvest. For most, though, doubling the amount of harvests is achievable (and should probably supply enough weed anyway).

Tips For Faster Outdoor Grows

Harvesting early outside is a little tricky. The obvious answer is to use autoflowering strains—and this does work. Depending on your weather, you may be able to harvest at least three times each growing season. Outdoor growers can also make photoperiod strains mature a little faster. Here are two things to try.

1. Cover Outdoor Plants To Force Bloom

Cover your outdoor plants with a tarp or other light-proof cover in the early evening and remove it the next morning. This works just like a grow tent to give your plants 12 hours of darkness each day to force them to bloom. As a bonus, you'll end up with bigger, denser, more resinous buds when you're done because the sunlight they do get, during the height of summer, will be much more intense than what they would receive during the fall months when outdoor cannabis plants normally bloom.

2. Pollinate Late, Harvest Early

This last tip might shock you. Pollinate your flowers and they'll ripen faster.

This doesn't mean you'll ruin your grow with a bunch of seeds. Pollinate by hand about a week before you want to harvest. As soon as the buds are fertilised, the plant will switch its energy away from flower formation to seed production and the maturity rate will escalate. The next week, when you harvest, the seeds won't even be noticeable because they haven't had time to form a hard shell.

3. Cannabis Seed Selection Is Key To Faster Growing

If you want to grow cannabis as fast as possible, choosing a seed that's been bred to mature quickly is key. It's only common sense that it will be easier to hurry along a strain that will finish on its own in 7 weeks than one that prefers 12. Luckily, fast strains have been bred to meet every need and preference.

For those who prefer autoflowering hybrids, Northern Light Auto is a great choice. The original was already fast, but this improved version can go from germination to harvest in 10 weeks or less without any extra measures. Royal Cheese is a photoperiod strain, but this European favourite only needs about 6 weeks of 12/12 lighting to reach full maturity. Medical marijuana patients who are on a tight schedule should take a look at Medical Mass. This variety only needs 7 weeks of bloom to yield up to 550g/m² of CBD-enriched flowers.

Northern Light Auto		Royal Cheese		Medical Mass

Northern Light Auto

Royal Cheese

Medical Mass

4. Progressive Harvest

This is the simplest way to speed up your harvest, gaining you somewhere between one and two weeks, depending on a couple of factors.

Flowers may mature at different times, and a progressive harvest simply means harvesting the mature ones, and leaving the rest on the plant to finish ripening. Usually, but not always, the flowers at the top of the plant will mature first, and the ones at the bottom will mature last. But don’t just assume this is the case; genetics and environmental conditions may say otherwise, so check your buds!

However, usually you can harvest the first batch of buds, trim the plant down, and harvest the second lot a week or two later. The added benefit of this is that those lower buds become the main canopy and get an extra dose of light in their final stages, hopefully increasing their overall size and potency. This means that not only is a progressive harvest no worse than single harvest, but potentially better!

Conclusion — How To Speed Up Your Cannabis Grow

If you need to force your plants to mature faster than they naturally would, you can by trying one or more of the methods described above. Doing so, however, means that you will probably sacrifice both yield and potency in the process. For the best results, choose a cannabis seed that's been bred specifically for speed. With the right genetics, you can minimise any type of compromise that you may have to make.