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how big can autoflowers get

Low-stress training (LST) is a non-destructive training technique that even beginners can use. As the name implies, it is a minimally invasive technique that doesn’t involve any major damage to plants.

If you’re an expert grower and not afraid to put a knife to your plants, you can see whether topping will work for you. Just ensure that everything else is under control before looking into these more-involved plant training techniques.

The bigger the pot, the more the roots will develop and the bigger your plant will be. If you constrain it in a pot that’s too small, your plant’s development and production will be reduced. It is recommended that you use 15–20-litre pots to maximise results without overwhelming your plants. A pot that is too big will be a waste of substrate and fertiliser.


At times, just a simple standing fan or leaving a window open is all that’s needed to create an optimal growing environment. If that doesn’t cut it, look into solutions such as a heater or air conditioner for your grow room.

Autoflowers have finally earned the respect they deserve. More importantly, they have earned a place in your grow room. With our guide to achieving maximum yields, you will crop the biggest harvest possible from your autoflowers!

It is scientifically proven that plants use CO₂ as fuel for photosynthesis, and with more CO₂ in your grow space, there should be a noticeable difference in growth rate and size.

Indeed, you could potentially grow them with less light, but we are aiming for a huge harvest, so you’ll want to provide them with as many lumens as possible. More light, more buds. Easy.

Usually, we use the following table as a guide:

When calculating how many square meter per autoflower you need, this is the first thing we should have in mind, a Sativa-dominant hybrid can grow more than 2 m (6.5 ft) tall if no training is applied, while an Indica hybrid can reach up to 1.4 m (4.5 ft) tall. So, if you’re looking to grow Sativa-dominant strains, you won’t be able to fit as much in your grow tent as if you were growing Indica-dominant cannabis.


Have in mind that all cannabis plants are different and they will grow according to the environment they’re in, so even if it’s the same strain, growing it outdoors and indoors will result in slightly different (or completely different) growth which can be seen in how much your plants stretch, yields, aromas and effect so if you want are planning on cloning a certain plant, make sure you grow it in similar conditions, either outdoors or indoors.

Tip: If you’re measuring in cm, divide the result by 100 to have the area size in m 2 . For example: 200 x 400 = 800 cm 2 , 800 cm 2 ÷ 100 = 8 square meter.

In our example, we were using 15 L pots so according to the table, we need to multiply the area by the number of plants, so it would be 6 x 2 = 12. This means we could fit 12 plants in a 6 square meter (64.5 ft 2 ) area when applying the tie-down method. To calculate the wattage needed for those 12 plants, we have to multiply the number of plants by 75 W, so 12 x 75 W = 900 w

The pH is an important factor in determining the yields of autoflowering cannabis strains. Whether you grow hydroponically or use soil as a medium, pH is critical. Although many growers assume that the plant is suffering from nutrient deficiencies, most issues crop up only due to pH imbalance.

In particular, full-spectrum LEDs work the best for any type of autoflower. The higher the lumens, the better the yields, but if you cannot afford expensive lighting equipment, CFLs will work well during the vegetative phase.

It’s common for beginners to load their plants with too many nutrients and burn them. We get that you love your plants, but you’re only harming your autoflowers by feeding extra nutes. Photoperiod plants have bigger roots, but autoflowers are comparatively smaller and the nutrients have to be adjusted accordingly.

1) Prepare ahead

Cannabis growers are always on the hunt to understand the tips and tricks to maximize yields in autoflowers. Most growers have the talent, but they lack information. And that’s a serious handicap when growing autoflowers. Autoflowers grow fast and produce yields in a short span of time, but that comes only with experience. You could grow them just like photoperiod plants, but there are several stark differences.

Autoflowers grow even when they get only 12 hours of light from seed to harvest. They are tough and adapt in any situation; however, they thrive when they receive 18 hours of light and 6 hours of darkness. Some growers provide 24 hours of light from the beginning until harvest, but it’s not recommended because plants need some rest and time to recover like the rest of us.

For autoflowers growing in soil, pH levels ranging from 6.0 to 7.0 is adequate while hydroponic systems do well from 5.5 to 6.5. It’s not necessary to get an exact number, so an average of levels starting from 5.5 to 6.5 is good for autoflowers.