How to grow a perpetual harvest with auto-flowering cannabis (step-by-step method)

If you like the idea of never running out of weed at home ever again, then a perpetual auto-flowering harvest is exactly what you need! In this article, I will explain how to easily achieve a continuous cannabis harvest, and cover lighting requirements and genetics.

How to set up a perpetual harvest autoflower system, how to stagger autoflowering plants, and provide my top tips. Once you put this system into practice, you will never be short of indoor-grown buds ever again!

Autoflower cannabis simplifies indoor growing by removing light-cycle dependency, allowing growers to maintain a predictable, continuous harvest schedule.

What Is a Perpetual Harvest Autoflower System?

A continuous cannabis harvest sounds like a dream come true. If you already like the idea of endless fl2owering plants, then the autoflower grow cycle could be destined for you. Below is a breakdown of how it works, how you can produce a continuous cannabis harvest and the art of staggering autoflower plants.

How Does It Work?

Autoflowering cannabis seeds have a shorter lifecycle than photoperiods ¹, as they begin producing flowers and buds after 28 days of growth. The majority of autoflowering cannabis plants on the market take between 77 and 84 days before they are ready to harvest.

The goal is to plant new autos every 3-4 weeks, so as some plants are ready to harvest, new seedlings enter the grow space, ensuring you have some plants to trim and dry out in a separate drying room every 4 weeks.

Why It Produces a Continuous Cannabis Harvest

Pic 1 - This grower will plant 2 new seeds every 4 weeks using 30L fabric pots outside

Autos are uniform plants that typically grow around 100cm tall. A 1.2-meter grow tent can fit 9 autoflowering plants without risking overcrowding. With 9 plant pots, you will end up with three rows of three plants. In this scenario, every 4 weeks, one row of three would be ready to harvest, and three new plants would enter the tent to fill the space.

• Three plants are taken to the dry room to hang out every 4 weeks
• At no point are any of the rows of three plants empty
• A separate dry room is required for a continuous cannabis harvest
• Autos will have a seed to harvest life cycle of 11-12 weeks

Lighting, Genetics & Growth Speed

Indoor autos are at risk of exposure to long hours of intense light. They can produce impressive yields and superb bud quality. Below is an explanation of which light cycle is required for the perpetual harvest autoflower system.

What’s Better – 24/0 vs 18/6 Autoflower Lighting?

Keeping your grow light on for 24 hours a day may give the plants more light than they could ever have wished for, but there are downsides. Cannabis plants require darkness, so giving them a dark period is advised; your electric bills will be as high as possible.

Managing the growth of room temperature and humidity levels could be challenging. I would recommend giving autoflowering cannabis plants between 18 and 20 hours of light per day. Not only will your plants be happy with the darkness period, but your electric bills will also be significantly lower.

How Much Light Do Autos Need?

When asking how much light do cannabis plants need ²? You should try and keep PPFD levels between 600 and 1000 µmol/m²/s when growing autos from seed to harvest. Avoid going higher as plants can be prone to stress.

Why Fast Flowering Strains Are Best

Fast-flowering strains are best for turnaround time. The faster your autos are flowering, the more harvests you can achieve over the space of a year. (add list of fast-flowering autos)

Setup & Grow Room Design

You would be surprised at how simple it is to get started on your perpetual autoflower grow project! The most important factor is that you have a separate drying area ready to hang up your harvested plants. Below, you will find exactly what you need to get the ball rolling.

What You Need to Set Up a Perpetual Autoflower Grow?

• 1.2 meter grow tent
• HID grow light
• Extractor
• Carbon filter
• 1m drying tent / dry room
• 9 x 20 litre pots
• 200 litres of soil
• Grow timer set to 18/6
• Nutrients
• Pack of autoflowering seeds

How to Plan It Step by Step

Pic 2 - An example of 9 pots in rows inside a 1.2m grow tent.

As long as you have 9 pots and your pack of autoflowering seeds, then you are one final step away from officially being a master of staggering autoflower plants. Below is a step-by-step guide.

1. Place 9 pots inside the grow tent and fill with soil.
   
   
2. Germinate 3 autoflowering seeds in the first row of the pot.
   
   
3. After 28 days, germinate 3 more seeds for the second row.
   
   
4. 28 days after, germinate 3 more seeds and harvest 3 plants.
   
   
5. Repeat this process every 28 days.

Why Harvesting Every 4 Weeks Works Well

What I like about the perpetual harvest autoflower method is that there is no heavy workload or maintenance required. Every 4 weeks, you harvest enough plants to keep you busy in trim jail for 2–3 days without overwhelming you or taking too much time out of your schedule. Plus, the fact that you know you will have the opportunity to harvest 12 times a year!

My Top Tips for Running An Indoor Perpetual Grow Setup

Tip #1: Use 20L pots

Using large pots, such as a 20L, will give the autos the best chance of developing a deep root base. Autos grown in small pots always end up dwarf-sized and produce little yield. 9 x 20-litre pots inside a 1.2 m² tent is the formula to follow, based on my experience.

Tip #2: Fast Flowering Autos

If you can buy yourself some fast-flowering strains, then you can really take advantage of a fast turnaround time. There are plenty of good autos that can be ready to harvest in 10 weeks, making them ideal candidates for achieving a continuous cannabis harvest.

Photo 3 - Autos produce uniform plants that work well in tight grow spaces

Sources

1. Grow Weed Easy – Cannabis Light Schedules: Photoperiod vs Autoflower
2. Skunk Global Marijuana Culture – How Much Light Do Cannabis Plants Need?

Read more about this topic

Want to dive deeper into autoflower cannabis, different growing methods, and smart harvesting strategies? Be sure to check out:

• All articles about autoflower seeds
• How to germinate cannabis seeds successfully?

This way, you’ll build a strong foundation for a healthy and successful grow.

Frequently asked questions about autoflower cannabis