A Beginner’s Guide to Auto-Flowering and Photoperiod Cannabis Plants 

The outdoor growing season is upon us, which means choosing the best genetics. As a beginner grower, you will have the option of growing auto-flowering or photoperiod cannabis plants. If you are unsure of the differences and which is best suited for you, this article will explain everything you need to know.

What Are the Main Differences Between Autos and Photoperiods?

Cannabis genetics are incredibly diverse and are available to both autos and photoperiods. Even though they may look the same and produce the same buds, trichomes, and terpene profiles, both are unique. Below is a breakdown of auto-flowering plants.

The Characteristics of Auto-Flowering Weed Plants

• Autos are typically short to medium-sized cannabis plants.
• Autos do not need 12/12 to be flowering and produce buds.
• An auto’s life cycle is between 10 and 12 weeks from seed to harvest.
• Outdoors and autos can be perpetually harvested from Spring to Summer.
• Auto-flowering cannabis plants are crossed with the Ruderalis genetics.
• Autos are tough, resilient and well-adapted to all types of weather.
• It is not possible to clone, auto and create a mother plant.
• Autos will stay in a vegetative state for 28 days before flowering.

Plant Training Techniques and Auto-Flowering Cannabis

Due to the short growth period associated with autos, plant training is limited due to recovery time. Auto-flowering weed plants do not react well to topping and super cropping, and using the low-stress technique is an excellent way for a beginner grower to achieve maximum yields.

3 Benefits of Growing Auto-Flowering Cannabis Plants

1. Indoors, autos can be left to grow under 18-20 hours of light and do not depend on a 12/12 light cycle. They are an excellent starting point for a first-time grower and achieve great results and a top-quality yield.
2. Because auto-flowering plants only require 10-12 weeks from seed to harvest, they can be harvested 2-3 times over the summer months, allowing a grower a low-maintenance weed garden and the opportunity to keep their curing jars full.
3. Growers can rely on autos to perform well and grow without issues in cold and harsh climates. This is because they contain the Ruderalis gene, which was initially found in Siberia and is well adapted to handle challenging weather.

The Characteristics of Photoperiod Weed Plants

• Photoperiod plants can become tall, large and bushy plants.
• Clones can be taken off photoperiods and turned into a mother plant.
• A grower has plenty of time to train photoperiod cannabis plants during 18/6.
• Photoperiods can produce massive yields, mainly when grown outdoors.
• Indoors, photoperiods need 12 hours of darkness to induce flowering.
• Plants can be suspended in a vegetative stage for extended amounts of time.
• Male and female photoperiod plants, when crossed, produce first-generation seeds.

Plant Training Techniques and Photoperiods

Unlike autos, photoperiod weed plants can be kept in a vegetative state for long periods. This means they have plenty of time to recover from all the plant training techniques. Applying plant training techniques such as topping, tying down, super cropping, fimming, and lolly popping can significantly enhance the plants’ shape and structure, resulting in improved yields.

3 Benefits of Growing Photoperiod Cannabis Plants

1. Photoperiods are ideal for taking clones off (a genetic replica) and turning them into bushy mother plants. Doing so means a grower can source infant-sized plants for future indoor grows and eliminates the need to buy seeds.
2. When planted in Spring, photoperiod will grow in a vegetative stage for up to 4 months. This is one reason why they can grow as tall as 6-10 feet and can produce pounds of cannabis buds once harvested.

3. Photoperiods will produce different phenotypes, allowing a grower to take a clone and decide the most desirable plant from one pack of regular or feminized seeds. This is especially useful when breeding or selecting your favourite plants from a large population.

Do Autos Yield as Much as Photoperiod Plants Indoors?

Because a grower using photoperiod plants can vegetate and train their plants for long periods, technically, autos do not yield as much; however, yields from the best auto flower seeds can be several hundred grams per plant from well-grown indoor autos, according to Dutch Passion.

Are Photoperiods More Potent Than Autos?

Considering that autos are created from crossing photoperiod cannabis plants; the potency can often be as strong as buds from photoperiod plants. As far as looks go, autos produce frosty, sticky, cannabinoid-rich buds.

Common Mistakes to Avoid When Growing Autos

Autos are very easy to grow, require little maintenance, and, with high amounts of intense light and nutrients, can be superb performers indoors and outdoors. Below are some common mistakes for a beginner grower to avoid.

Using Small Pots

Avoid using small pots when planting autos. Using 6–8-gallon pots is best to prevent little stunted plants that produce low yields. Big pots will promote taller plants, around 90 – 100 cm tall.

Repotting Autos

Repotting an auto once it has passed week 4 can cause the plants to become stressed and slow down growth. Avoid transplanting autos to a larger pot; it is best to plant directly into a large pot and leave the plants to develop a strong root base.

Taking Clones Off Autos

Unlike photoperiod plants, it will be a waste of time and resources attempting to clone auto-flowers. As advised by Auto-Seeds, the result will be a tiny auto flower plant that doesn’t grow much bigger than the clone itself before flowering.

My Final Thoughts

There are many benefits to working with autos and photoperiods. Autos are brilliant for small indoor spaces and keep a low profile outdoors, only taking 10-12 weeks to harvest. Photoperiods can require much more time and maintenance, but they reward a grower with huge yields and the opportunity for pheno hunting and take clones.

Feature image: A room full of photoperiod cannabis plants grown from clones. Photo credit: Bill Sutherland