Autoflower strains have earned their reputation for being the easiest and fastest way to grow cannabis.
They are often recommended to beginner growers due to the wide range of grow conditions which they can thrive under. If you’re a less experienced/beginner grower, or an average grower wanting to achieve better results indoors then read on.
Our indoor autoflower grow guide will explain several easy-to-implement top tips from autoflower professionals which will maximise your yields and potency. Autoflowers really are easy to grow. And if you choose the best autoflower seeds you can expect THC levels of 25-30%. Autoflower strains are not only easy to grow, but the best ones also deliver truly spectacular results.
Benefits of growing autoflowers indoors
You can grow an autoflower all the way through to harvest using a fixed light cycle – 20 hours of daily light gives great results. Autos may seem a little bit easier for some than growing photoperiod feminised seeds which require a change of light cycle (to a 12/12 cycle) to initiate bloom. Grow the best auto seeds and your potency levels will be right up there with the best feminised strains. Your yields may even be higher. And with a fast 11-week auto life cycle you can be cropping your harvests at a rapid rate.
Top 10 beginners’ tips for growing autoflowers indoors
Growing autoflowers indoors is the easiest and fastest way to produce cannabis. It’s so easy that even first-time growers have produced top quality debut crops when growing in a reasonably well optimised grow room. The following expert tips can help you upgrade from average crops to cannabis-cup winning quality.
Tip 1. Avoid over-watering, waterlogged roots should be avoided!
One of the most frequent mistakes committed by beginner indoor autoflower growers is the tendency to over-water their seedlings and plants. This deprives cannabis roots of the oxygenated environment in which they thrive. Use of a hygrometer can be useful since they show the precise soil moisture content. This can help prevent the plants from being over-watered.
Tip 2: Choose the best autoflowering genetics for YOUR needs
You can select sativa, indica or hybrid autoflower seeds depending on your personal preferences. Many autoflowers tend to reach around a metre in height but check with the description from your auto seed supplier if, for instance, you have grow room height concerns. Some autos such as Auto Blueberry and Auto Blackberry Kush can be ready to harvest in as little 8-9 weeks after autoflower seed germination. Other strains such as Auto Ultimate, Auto Glueberry and Auto Desfrán can take nearer 13+ weeks from autoflower seed to harvest but reward the grower with ultra-heavy harvests. Research your autoflower genetics carefully, selecting only the best seeds for your particular needs and preferences.
THC levels can vary widely from the professional seed suppliers down to less scrupulous suppliers that just buy/sell seeds with little idea of the genetics or breeding quality. Autoflower THC levels typically vary from 10% to 30%. The most potent autoflower strains benefit from many years of professional breeding and stabilisation.
Tip 3: Start your plants in their final container to save time
Many growers start the autoflower seeds in their final container. Autoflowers have a fixed life cycle, typically around 75 days from seed to harvest. For that reason, cannabis growers often prefer to avoid the delays and hassle associated with re-potting the plants into new containers.
Many of the top autoflower growers get the best result with large, aerated grow containers such as air pots or felt grow sacks. These allow the cannabis roots to thrive in a highly oxygenated environment. If you haven’t tried growing with air pots or grow pouches, they are highly recommended for indoor autoflower growers.
Tip 4: Use the right type of light, LED for the win
Most serious growers know that LED produces superior results to HPS. With LED you can expect higher cannabinoid and THC levels. You can also expect a superior terpene profile. HPS, with its inherently high levels of plant-stressing heat and sub-optimised light spectrum may be cheap to buy but the results simply can’t compare with LED-grown cannabis.
Tip 5: Be cautious about topping autoflowers
Some experienced autoflower growers routinely ‘top’ their auto, removing the growing tip. Although this can take the auto some time to recover from it can also produce extra-bushy growth. Some growers claim it can improve their yields. However, if you’re not that experienced it can be safer to allow the plant to grow naturally, without topping. It should still deliver great results.
Tip 6: Avoid over feeding and under feeding
One of the most common problems for beginner autoflower growers is getting nutrition right. Under feeding deprives your plants of essential nutrients/minerals. This limits growth, yield, resin production and potency. Over feeding stunts (limits) the growth of your plants. Often you will see burnt, brown leaf tips. That’s a sure sign of over feeding, a signal that your genetics won’t reach their potential.
Growing in large aerated 50 litre+ containers of nutrient-rich compost can be one way to avoid these issues. So can the use of slow-release organic nutrients such as BioTabs. With large volumes of soil, e.g. 50-75 litres or more, your autos may not require any additional nutrients. If they do, it’s likely to be just a touch of general-purpose bloom nutrients near the end.
Tip 7: Consider supplementing your grow room with UVA and UVB
Many expert/pro growers add UVA and UVB light to supplement their main LED light. Fluorescent light tubes are the best and most cost-effective way to add extra UVA/UVB and can increase both cannabinoid levels as well as boosting the terpene content.
Tip 8: Control pH levels throughout the grow
If you’re growing in coco fibre or hydroponics you will need to monitor pH levels (and perhaps EC, electrical conductivity) of your nutrient feeds. Even if key minerals are present, they may not be completely bio-available if the pH is too far from optimum. Pay close attention to the nutrient manufacturers guidelines and where necessary consider using pH adjustment liquids.
One other important tip for those that rely on pH meters is to regularly calibrate them. It’s also important to be prepared for the inevitable day when your pH meter will fail. For that reason, many pro-growers keep a spare pH meter.
|Nutrient||Ideal pH Level for Absorption|
|Nitrogen||6.0 – 8.0|
|Phosphorus||6.5 – 7.5|
|Potassium||6 – 8|
|Calcium||6.5 – 8.5|
|Magnesium||6 – 8.5|
If you’re growing in soil/compost (often this is a recommended approach for beginner growers) then there is an element of natural pH buffering. This means that, in general, many soil growers often don’t worry about pH.
Tip 9: Choose the right medium for your autoflower
The numerous choices of grow mediums and grow systems may confuse the less experienced grower. Hydroponics may produce some monster plants, but the technicalities involved may be too much for the less experienced grower. Coco fibre may seem a simpler option but even that can be a little too complicated for beginner growers who may lack the confidence to check pH and electrical conductivity of the feed solution. That’s why many growers feel the simplest cultivation approach is to grow in large, aerated containers of organic nutrient-rich soil (e.g. 30-50+ litre air-pots or felt sacks).
Tip 10: Harvest at the right time
Do you know whether you prefer buds that are early harvested, late harvested or harvested somewhere in between? If not, it could be worth finding out. If you grow your own, try evaluating buds harvested at different times over a couple of weeks from the same plant. Many growers find that allowing an extra week or two at the end can produce heavier effects as well as boosting cannabinoid levels and yields. Check trichome appearance, pistil (hair) colour and general bud/plant appearance. Harvest at the optimum time for you.
Keep your autoflower grow simple!
Keeping things as simple as possible can minimise the scope for errors and interventions. For less experienced autoflower growers this can make all the difference. You may also want to keep a diary of each grow, recording your main learnings and mistakes. Growing autos is easy, great fun and highly rewarding. Enjoy your grow!