A Guide to Growing Autoflowering Cannabis Seeds

Written by Trevor Hennings | 03 Aug 2019
📷 Maclean's

When you decide to start growing cannabis, you might find yourself looking at online seed catalogs. Here you’ll see companies offering strains that are dubbed “auto-flowering,” but what does this mean and why might a grower choose auto-flowering varieties of cannabis?

What is auto-flowering cannabis?

The concept of auto-flowering strains is simple: in time, they will automatically flower as opposed to waiting for a specifically timed light cycle. In other words, the plants begin to flower all on their own after a relatively short vegetative period of 2-4 weeks.

This unique process is created when breeders fold in genetics from Cannabis ruderalis, a subspecies of the cannabis plant that is known for its auto-flowering attributes and short stature.

Crossing the auto-flowering ruderalis with indica and sativa varieties results in a plant that doesn’t rely on photoperiods to flower, but rather grows and flowers on its own time.

The pros and cons of growing auto-flowering cannabis seeds

There are a number of reasons to consider auto-flowering varieties for both indoor and outdoor cannabis:

  • When grown outdoors, auto-flowering plants will start producing buds no matter how many hours of sunlight you are receiving; this means you don’t have to worry about running a light deprivation system or supplementing light if you are trying to achieve multiple harvests in the season.
  • When growing indoors, auto-flowering strains allow you to rapidly grow strains from start to finish as they generally complete maturation after three months.
  • Auto-flowering plants can receive more than 12 hours of sunlight a day and create bigger buds in less time than many regular cannabis plants.
  • Auto-flowering plants are small and stealthy; they are perfect for closet grows or growing outdoors where you don’t want your neighbours to see what you’re up to.

There are, however, reasons why auto-flowering plants are not as popular as regular cannabis indica and sativa plants. Auto-flowering strains are small in stature and do not produce large yields. Other issues with auto-flowering strains include higher electricity bills and an inability to really train your plants to make the most of your grow space.

Since the introduction of original auto-flowering strains in decades past, significant improvements have been made to these genetics. First, potency in auto-flowering varieties has increased significantly since their initial introduction. Also, there are now hundreds of types of auto-flowering seeds being sold, giving you a large selection to choose from. Because of these improvements, auto-flowering seeds are worth a shot for any curious gardener looking to try something new.

How to grow auto-flowering cannabis strains

Auto-flowering strains require some preparation, as they will grow quickly and start to flower whether or not you’re ready for them. However, follow these steps and you should find success in your auto-flowering garden.

1. Training your plants

Generally speaking, you’ll want to train your plants while they are in vegetative growth. For auto-flowering plants, this period could be as short as two weeks which means time is limited.

To start, consider topping your plant after it has developed three nodes to promote a more even canopy. Another LST (low-stress training) method involves training your plant by pulling it down sideways to create new upward growth. Once your plants do begin to flower, you should not top them. Prune your plants conservatively for no more than one week into flowering.

2. Climate considerations

When you are growing auto-flowering plants, you’re allowing plants to flower when they should be in a vegetative growth. Because you don’t need to follow photoperiod light cycles, many people start auto-flowering plants early in the season (e.g. March) or late in the season (e.g. September). For this time of year, it’s important to remember that the plants still need warmth to grow, and there also might be considerable rain putting the buds at risk of rot. To combat these issues, consider growing in a greenhouse to provide protection from the elements.

3. Go easy on feeding

Auto-flowering strains do not need to be heavily fed due to their small size and the short amount of time they spend in the vegetative cycle. Feed very lightly and understand that they don’t need as many vegetative growth nutrients such as nitrogen. Also note that these vegetative nutrients are best put to use if they are readily available for the plant to utilise quickly.

4. Harvest gradually

Auto-flowering plants often do not have time to develop a canopy, which means you will be keeping buds that are lower down on the plant. Because of this, it’s a great idea to harvest your plants sequentially. First take the colas, then allow more time for the lower buds to dense up before they are harvested next.

5. Prepare your next crop

To get the most out of auto-flowering seeds, it’s a good idea to prepare your next batch of plants as you are harvesting. This means popping seeds before you harvest your current plants so that your room is continually producing. Because the plants auto-flower, you can have plants that are just starting out in the same room as those that are finishing without worrying about the lighting.

How to find autoflowering cannabis seeds

Auto-flowering cannabis seeds are most easily found through seed banks and seed banks online (note: just be sure to read and understand the legal fine print about purchasing seeds online). Seeds may also be purchased at some local dispensaries, though depending on where you are, they can be difficult to track down at retail outlets.

Have you tried growing auto-flowering strains before? Share your experience in the comments below and let us know how they turned out!

Source: Leafly