week by week autoflower grow guide

Growing autoflowers is both an art and a science and their requirements change on a weekly basis. This article serves as your comprehensive guide of the life cycle of an autoflower from seed to harvest with weekly snapshots. 

We’ll chart each stage of growth and offer expert insights into optimizing plant health and yield. While autoflowers do much of the work themselves, understanding how your autoflower changes will enhance your cultivation skills and maximize your results. 

Buckle up, let’s get growing!

Week 1: Germination and Seedling

In the initial week, your autoflowers life begins with germination. This is when the seed splits open, and a taproot emerges, searching for nutrients. By the end of the week, you’ll notice a tiny seedling with its first set of rudimentary leaves. 

Seedlings require no added nutrients. Pure water with a neutral pH is usually sufficient as the seed contains all the necessary nutrients for this stage. If you are growing in nutrient-rich soil, additional feeding could do more harm than good, leading to nutrient burn.

At this stage the primary focus should be on providing stable conditions, including gentle light and humidity until the vegetative stage begins. 

It is important to understand, that transplanting autoflowers isn’t recommended because their rapid growth cycle leaves little recovery time from potential stress or damage, which can hinder overall yield and plant health. So ideally you should decide what pot size to grow your autoflowers in from day one and keep them in this pot throughout their life.

Week 2-3: End of Seedling Stage & Start of Veg Stage

autoflower cannabis plant transitioning from the seedling to vegetative stage

During weeks 2 and 3, the autoflower transitions from the seedling stage to the vegetative stage. This is where you’ll witness some of the most rapid growth. The seedling begins to develop multiple sets of true leaves, which are larger and more complex, indicating that it has moved into the vegetative phase.

At this stage, the autoflower’s nutrient needs begin to increase. You can start introducing a balanced, light-strength nutrient solution, focusing on nitrogen, which promotes leaf and stem growth. Make sure to follow your nutrient manufacturer’s instructions and always err on the side of caution; overfeeding can harm your plants.

You need to remember that most store bought nutrients are designed for photoperiods, as such the guidelines will need to be adjusted. You can normally start by giving 1/8 of the recommended amount, increasing to about 1/2 to 1/4 during the flowering stage. Read our guide on the best nutrients for autoflowers for depth instructions on this.

As the plant grows sturdier and taller, it’s also the appropriate time to consider beginning low-stress training (LST). This technique involves gently bending and tying down branches to optimize light exposure and encourage more bud sites. 

It’s crucial to be gentle during this process, as the plant is still young and can easily be damaged. Remember, your ultimate goal is to enhance growth, not hinder it. So approach this phase with an attentive eye and a steady hand.

Week 3 – 4: Autflower vegetative stage

autoflowering plants in the vegetative stage

Weeks 3 to 4 are the heart of the vegetative stage for autoflowers, and your plants will be in full swing. You’ll notice a dramatic change in appearance as the plants gain height, produce new branches, and form a bushier structure. 

This expansion is accompanied by larger, darker green leaves, which work as solar panels, capturing light energy for photosynthesis.

In terms of nutrients, autoflowers during this stage have an increased demand for nitrogen, along with balanced quantities of phosphorus and potassium. 

Continue feeding a light to moderate strength nutrient solution, while always observing the plants’ reactions. If any signs of nutrient burn or deficiency occur, adjust accordingly.

When low stress training your autoflowers, regularly adjust your ties and gently train branches to grow horizontally, promoting even canopy growth and ensuring light penetrates all areas of the plant. Remember, the aim of training is to increase yield potential, so always handle your plants with care to avoid causing stress or injury.

Week 4: Late Vegetative Stage

autoflower cannabis plant in the late vegetative stage

In week 4, you’re at the tail end of the vegetative stage. Your autoflowers are now in their prime growth phase, and you’ll see an impressive surge in height and foliage as they do one last stretch before beginning flowering. The plants are getting bushier and stronger, setting up the framework for future buds. 

You might even notice early signs of flowering, such as the formation of pre-flowers at the nodes.

The nutrient demand remains high during this week. Continue with a balanced feed, but start preparing for the flowering stage by gradually reducing nitrogen intake and increasing phosphorus and potassium. 

It’s a delicate balance; observe your plants carefully for any signs of nutrient stress.

Training should still be active during this stage, but remember that as the plants prepare for flowering, they become less flexible and more prone to damage. Therefore, it’s crucial to be gentle and avoid high-stress techniques. 

Any form of high stress can cause unnecessary delays or even harm the plant irreversibly. Your goal at this point is to guide your plants towards flowering smoothly and healthily, so treat them with care.

Week 5 – 6: Early flowering stage

autoflower plant in weeks 5-6 during tthe early flowering stage

Entering weeks 5 and 6, your autoflowers begin their transition into the early flowering stage. This transition is marked by a reduced growth rate in height and an increased focus on bud production. 

You’ll observe small bud sites starting to form along the branches and stem intersections. The once tiny pre-flowers begin to expand and develop, transforming into the first recognizable cannabis buds.

As the flowering stage initiates, the plant’s nutrient requirements shift again. Lower nitrogen levels are needed, and the demand for phosphorus and potassium intensifies. These nutrients support bud growth and development. 

It’s important to switch to a bloom nutrient formulation at this point to meet these changing needs.

Regarding training, as the plant transitions to the flowering stage, it’s time to reduce the intensity. The plant’s focus is now on producing buds, not growing stems and leaves. 

Therefore, any significant stress can hamper bud development. This is the time to step back, let your previous training efforts pay off, and allow your autoflowers to concentrate on creating those dense, buds.

Week 6 – 7: Flowering stage

autoflowering cannabis plant close up during the mid flowering stage

By weeks 6 and 7, your autoflowers are fully into the flowering stage. The small buds you saw in the early flowering stage will now begin to grow in size and density. 

You should begin to notice clusters of buds developing across the plant, and they will start to produce a distinct aroma that gets stronger as the trichomes and terpenes begin to develop.

During this stage, your plant’s nutrient demands remain high, but the focus stays on phosphorus and potassium, crucial for flower development. 

Continue using your bloom nutrients and consider introducing a bloom booster to further support bud growth. It’s still essential to watch for any signs of nutrient burn or deficiencies.

As for training, this is the time to take a hands-off approach. Any significant bending or manipulation of the branches could lead to damage and stress, which could negatively impact your yields. 

From here on out, your primary tasks are maintaining optimal conditions and watching your buds flourish.

Week 8 – 9: Late flowering stage and harvest time 

Week 8 9 late flowering 1

As you move into weeks 8 and 9, your autoflowers are approaching the late flowering stage, gearing up towards harvest. The small buds will now be solid and dense, chunky, and coated in a layer of trichomes. 

These tiny resin glands contain the cannabinoids and terpenes that give cannabis its unique properties. The smell is usually intense now, a good indication that harvest time is near.

Nutrient-wise, during these final weeks, most growers dial back their nutrients and towards the final 1-2 weeks begin the ‘flushing’ process. This involves watering your plants with plain pH-balanced water to flush out residual nutrients. Flushing improves the taste and quality of your buds by eliminating any excess nutrients.

At this stage you need to focus turns to checking the maturity of your buds for harvesting. This is typically done by observing the color of the trichomes with a magnifying glass. When 60-80% of the trichomes have turned milky white and some are amber, it’s generally a good time to harvest.

After weeks of attentive care, its finally harvest time. This is the moment you’ve been patiently waiting for – cutting, drying, and curing your buds.


How long does an autoflower take to grow?

An autoflower typically takes between 8 to 10 weeks to grow from seed to harvest. However, this can vary depending on the specific strain of autoflower and the growing conditions. Indica varieties can be ready for harvest in as little as 7 weeks, while sativas might require up to 11 or 12 weeks.

What does an autoflower look like when it starts to flower?

When an autoflower starts to flower, you’ll see a few noticeable changes. The most obvious one is the appearance of white, hair-like structures known as pistils at the plant’s nodes, where the branches meet the main stem. These pistils, initially white or light yellow, are part of the plant’s reproductive system and eventually develop into the cannabis buds.

Another change is the formation of calyxes, which are small, teardrop-shaped components that house the pistils and later form the bulk of the buds. As the flowering stage progresses, these calyxes will multiply and swell, forming clusters that become the recognizable buds.

What week do Autoflowers start to stretch?

Autoflowers typically begin to stretch, or undergo a rapid increase in height, during the transition from the vegetative stage to the flowering stage. This usually occurs around weeks 3 to 5, depending on the specific strain and growing conditions.

During this “stretch” phase, autoflowers can often double or even triple in size as they prepare for the flowering stage. The plant focuses energy on upward and outward growth to support future bud production. This growth spurt is often accompanied by the first signs of flowering, such as the emergence of small bud sites.

How long is an Autoflower in the seedling stage?

The seedling stage of an autoflower usually lasts about 1 to 2 weeks from the time the seed germinates. During this period, the seedling develops its first sets of leaves.

The initial leaves, called cotyledons, are round and emerge as the seed casing splits open. These are followed by the development of the first true leaves, which have the classic serrated, multi-fingered shape typical of cannabis plants. As the seedling develops more of these true leaves and begins to increase in size, it’s transitioning into the vegetative stage.


In sum, our week-by-week guide helps you navigate autoflower cultivation from seedling to harvest. You’ve learned crucial stages, signs of growth, and timely responses, enabling you to manage your next grow proficiently. Cultivation success is within reach with this knowledge. If you appreciated this guide, don’t forget to like and share the article. Grow on, autoflower enthusiasts!

Joe Musgrave

An avid 420 enthusiast, grower, smoker and writer. Joe writes non stop, sharing his extensive knowledge in the field of cannabis with the wider online 420 community through blogs like ours at High Yield Strains.

Leave a Reply