How Tall Do Autoflowers Get? Everything You Need To Know

How tall do autoflowers get? Generally, Autoflowersare about 50 to 100 cm long, but some can grow up to 150 cm, although they are genetic. The final height of the plant can be controlled to some extent by using the correct photoperiod and pot size.

Autoflowers seeds have become an essential part of home growing. They are the fastest way to grow cannabis. As with any type of gardening, the final height of an automatic flowers plant can be affected by a range of different variables – from pot size, nutrient schedule and quality, type and distance of lighting, amount of stress experienced, and the presence of any pests or diseases question.

In this article, we explain average size of autoflowers, main factors that attect size, and how to grow autoflowers seeds, keep reading!

Average Autoflower Size

How big can a car flower be? What is the average size? The average height of most automatic flowers is about 50-100cm. The final automatic flower size depends on the genetics and growing conditions you provide.

The seeds of Sativa Autoflowersare slightly more stretched than India Autoflowers. Sativa auto genetics can also mature several weeks longer than Indica varieties, which can allow them to reach higher autoflower heights than more compact indica Autoflowers. The largest automatic flowers tend to be oblique sativa, which can reach a height of 1.25m-1.75m.

Since the average height of autoflowers tends to be shorter than photoperiod varieties, many growers find that they can use slightly smaller grow tents. This means that the recommended grow tent height for autoflowers can be shorter. You can grow autoflower seeds in a 1.5m high tent.

Main Factors Affecting The Size Of Autoflower

Main Factors Affecting The Size Of Autoflower

These are all major factors affecting growth, for better or for worse. They can seriously affect your autoflowering, and unlike secondary factors, they affect your plant more quickly, so they kill it quickly.

The main factors are as follows:

  • pot size
  • light distance and cycle
  • and nutrients.

Pot Size

Pot size is a very important aspect of the size of a automatic flowers and determines the limits of its growth. If the pot is too small, your plants will be root-bound (meaning the roots have no more room to grow), affecting nutrient intake. If you don’t transplant quickly, your plants won’t be able to breathe properly and are more likely to die or produce almost nothing.

We strongly recommend following the breeder’s information, usually, they will give an approximate height from which you can work. Ultimately, you can use these guidelines (remember, this is an estimate and may vary):

  • about 60 cm (23 in) – 7 liter (1.8 gallon) can;
  • Up to 100 cm (40 inches) – 8-10 liters (2.1-2.6 gallons) tanks;
  • 100 cm (40 in) and 12 liter (3.1 gal) tanks.

Light Distance and Cycle

All plants depend on light to survive, and autoflowering is no exception. This will not be a problem when grown outdoors. But if you’re an indoor grower, this is one of the most common problems people have. Artificially replicating sunlight is very difficult, and the size of automatic flowers is greatly affected by light distance and photoperiod

If the light is too far away, your plants will stretch too long and produce aerial shoots. If you get too close, your plants may get heat burn, which will stunt growth and won’t give you the expected yield.

You should always start with the brand’s recommendations and adjust accordingly to ensure your lights are at the perfect distance.

You also need to consider what type of lighting you want to use. There are several different options.

CFL or Fluorescent – By far the cheapest option for indoor cannabis growers. CFL lights are suitable for seedlings and are easy and cheap to install. They use low electricity and are easy to source, but lack the oompf needed to grow large, healthy plants that provide the dense, sticky buds we all know and love.

HID Lighting – High-Intensity Discharge or HID lights have been the gold standard for cannabis cultivation for decades. They offer excellent yield possibilities, are super reliable, produce consistent lighting, and are very simple to operate. But they also have some drawbacks. They generate a lot of heat, which can cause temperatures to rise and burn crops, they absorb a lot of energy, and the bulbs need to be replaced every year.

LED Lighting – LED grow lights are the new kid on the block. For years they were considered inferior siblings to HID lights, but these days the technology has reached a point where it truly surpasses all other options. They are more energy efficient than HID lamps and run cooler, meaning they can be placed closer to the canopy without lighting issues and produce huge yields with amazing terpene effects. They do come with a price, though, beware of the cheap panels flooding the online marketplace. Look for products from well-known companies such as Mars Hydro, Spider Farms, Bloomspect and Viparspectra.

Keep in mind that autoflower yields can be as low as 10 grams (0.3 ounces) and can exceed 150 grams (5 ounces) or more under ideal conditions if the desired light is not provided.

automatic flowers can be placed in cycles of 24/0, 18/6, or 12/12 (where the first number indicates light hours and the second number indicates dark hours; light/dark). We recommend giving your automatics at least 4 hours of darkness to allow your plants to rest. Effects may vary depending on the genetics of the breed.


automatic flowers are not picky eaters. They just need the right combination of nutrients to grow healthy and strong, resulting in higher yields and happier plants. Failure to provide the correct combination and amount of nutrients for each stage will damage the plant.

Providing too many nutrients can burn your plants. She will begin to show signs of nutrient toxicity and begin to struggle to absorb nutrients. This will make her sick, small, and underperforming.

If there are too few nutrients, your autoflower will show signs of nutrient deficiencies. Without nutrients, your plants cannot grow and can have similar results such as nutrient toxicity, stunted growth, and low yields. Without nutrients for a long time, your plants will die.

Steps For Growing Auto-flowering Seeds

1. Germination

Germination is fast with these seeds, taking just one to five days rather than up to ten days like some varieties. Dropping the seeds gently into a glass of room temperature water and keeping it in a dark place at a temperature of about 27°C is one of the simplest methods. After 72 hours, you can move it to a soaking wet paper towel and cover it with another wet one to keep it dark and warm. Transfer it to the soil once you see it sprout.

autoflower seed

2. Seedling

A seedling should be apparent by this point. Currently, the leaves are incredibly tiny. You can also give some nutrients at this point in addition to some light, such as a 250W LED. In comparison to photoperiods, auto-flowering varieties require only a quarter to half the nutrients.

3. Vegetation

For the best growing process, keep the environmental temperature no more or less than 20°C and humidity levels between 40% and 50%. daily supply of half a liter of water. In the later vegetative stage, you might even start to notice some flowering.

4. Flowering

Some sacs will now start to emerge from the nodes, as you will see. Autoflowering marijuana plants have a maximum height of just 60 cm. The temperature will rise by roughly 1 degree per week, reaching 25 degrees Celsius by the last week.

Where Can I Purchase Auto-flowering Marijuana Seeds?

The best marijuana seed banks online carry autos. The best seed for your needs will typically be listed with the other types of seeds, allowing you to click through and find them. Check before you buy because different strains come in different flavors and THC or CBD concentrations. Our selection offers the best seeds available, with a wide variety to choose from to meet your requirements.

Reasons Why Autoflowers Stays Small

You might be out of luck and just get a short squat phenotype. Don’t despair, many of these will still provide strong, firm buds. Or, you may have had the unfortunate growth of a problem that permanently hindered your car. There is a range of reasons why your autoflower is consistently small.

If environmental conditions (nutrients, pH, lighting, overwatering, etc.) are the cause, it’s worth noting that the car has a limited time to recover from any problems. The typical life cycle is 75 days, and if something goes wrong, there is simply not much time to recover and fix it.

You could also just be out of luck with your autoflower seed selection. Most of the top autoflower seed suppliers use reliable genetics and proven breeding techniques honed over the years. But there are still some notoriously unreliable seed companies that routinely produce substandard autoflower seeds. They use poor genes and have a higher chance of producing dwarf plants. The best advice is to choose the best auto seeds from companies with a proven track record in autoflower seed development, perhaps with a cannabis cup or two.

Note: Autoflowers Have A Shorter Growth Period Than Photoperiod Plants

Less time is available to overcome any challenges because autoflower seeds have a fixed growth lifespan, which is typically 75 days. An autoflower typically begins to bloom about a month after germination. In as little as 8 to 9 weeks after seed germination, autoflower seed varieties like Auto Blueberry and Auto Blackberry Kush can be ready for harvest. An autoflower lives a fast-paced life and has little time to recover from environmental or growth issues during the first few weeks of vegetative growth.

Low temperatures during an auto’s early growth stages can permanently reduce the ability of your auto to realize its full potential. Similarly, your autoflower plants may exhibit permanently stunted growth if you have serious nutrient problems, excessive watering, poor lighting, etc.

Contrarily, photoperiod plants have genetics that allow them to thrive in conditions favorable to vegetative growth for as long as you give them long (18 hour+) daylight hours. You can therefore give your photoperiod plants a few extra weeks to grow in the veg stage if they seem a little too small in your opinion.


Why Is My Autoflower So Tall?

In fact, tall cannabis plants can be a sign that they are unhappy—particularly, that they do not have enough light. Lack of light will affect the size and quality of your final crop in addition to making your plants stretch.

What Is The Tallest Autoflower Strain?

Orange Sherbet Auto. One of the taller autoflowering plants that can reach a height of 20 inches, this citrus-flavored, sativa-dominant strain has a strong indica flavor. Orange Sherbet Auto is an extra-large yielding cultivar that can produce up to 650 g/m2 and is ready for harvest in just 10 weeks.

What Size Pot Is Most Appropriate For An Autoflower?

To reach their full potential, autoflowers require a lot of grow medium in the early stages. What size pot should I use for autoflowers? We advise using a minimum 20-liter container for outdoor growing (XXL varieties should ideally use a 30-liter container). Containers of about 15-20 litres are usually adequate for indoor growers. Air pots and felt sacks (or something similar) work well. The best autoflower heights and the biggest autoflower sizes are typically attained by plants grown in hydroponic systems, such as deep water culture.

It is advised to either start the autoflower seeds in their final container or move them there right away after germination. Long-term storage of autoflowers in small containers will result in the same result—tiny plants that haven’t had time to grow.

How Tall Should My Autoflower Be At 2 Weeks?

They ought to measure about 8 inches tall.

How Much Do Autoflowering Plants Yield?

There are many auto-flowering genetics available in the Royal Queen Seeds catalog. We have a variety of flavors, scents, psychoactive effects, and sizes in our selection, so there is something for everyone. Each strain’s natural productivity varies a little bit as well. The average autoflower yield from most of our auto varieties should fall between 350 and 400 grams per square meter indoors and 100 to 150 grams per plant outdoors, compared to powerhouse anomalies like Watermelon Automatic, which can produce up to 500 grams per square meter.

Conclusion on How Tall Do Autoflowers Get

As some of the easiest and fastest-growing seeds, autoflowers are an excellent practical option for anyone just starting out. automatic flowers grow between 50cm and 100cm, with the possibility of only 1.8m for some Sativa varieties, ideal for small indoor gardens.

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