10 Reasons Why Your Autos Are Stunted and Small Plants

1. Small Pots

If you really want to grow big auto-flowering plants then you need to give the roots plenty of room to grow. Small pots less than 20 litres in size will struggle to produce a strong mass of roots, ultimately causing stunted and low-yielding autos. 

Make sure that you work with large-sized pots and use the right growing medium, to encourage the optimal root zone. Fabric pots are a great way to grow autos but only when they are large enough.

2. The Wrong Temperature

Auto-flowering varieties require a constant temperature that is between 22 - 25 degrees Celsius from seed to harvest. Autos can be particularly sensitive to cold temperatures and do not react well when the temperature is too hot and exceeds 25 degrees Celsius. 

Many indoor growers will try and keep their lights as low as possible, hoping to provide enough intense lighting, however doing so can have an adverse effect and result in heat stress which dramatically affects the roots and growth structure. 

3. Incorrect Humidity Levels

Temperature and humidity go hand in hand, especially when growing autos indoors. You will want to keep the relative humidity between 50 and 70% for the most desirable plants and to avoid stunted and squat characteristics. 

The best way to ensure your autos stay in the correct humidity zone is to use a digital hygrometer and make sure that your extraction and airflow are consistent and humidity levels do not increase or decrease too much when the lights are on or off.

4. Low-Intensity Lighting

Autos will remain in a vegetative state for the first 28 days, so it it during this time when they demand as much intense lighting as possible. One of the reasons many growers end up with short-sized plants is the fact they did not provide the right amount of intense lighting. 

Using a 600-1000w HPS or high-powered LED will do the trick, and will ensure that the growth structure and canopy are bushy and around 50-60 cm tall before the plants are triggered into flowering.

5. Poor Nutrition

Using a top-quality brand of soil combined with liquid nutrients is one way to keep your plant’s health in the ideal range and give them all the nutrients they need. This goes for the first 4 weeks and especially once they enter bloom at the start of week 5. 

Providing your auto-flowering genetics with a high amount of Nitrogen early on and a high P-K feed when the first lot of pre-flowers appear should set you on the path to a great yield and finish with medium-sized plants that are covered in resin and swollen fat buds.

6. Disrupting the Roots

Re-potting autos is never a good idea and the reason why is due to the amount of stress it can cause them. As the plant’s roots are establishing themselves, disrupting them to place them in a larger pot, can trigger them to flower earlier than anticipated, which leads to stunted growth. Planting your seeds directly into the growing medium and using one large container will make life easier and avoid any type of shock or stress.

7. Overwatering

How much water you give your autos will play a massive role in their performance, nutrient uptake, and availability. Over-watering and over-fertilizing them with liquid nutrients may lead to salt buildup around the roots, leading to slow growth and low yields. It is much better to lightly water them and wait until the growing medium is closer to the dry side. 

Autoflowering cannabis plants need an oxygen-rich growing medium, and if they become over-saturated and soggy, the roots can become susceptible to pathogens such as root rot. Insects and pests will also become attracted to wet conditions, so take extra care when feeding them. 

8. High-Stress Training Techniques in Flower

There will be a window of opportunity to apply training techniques to autos such as tying down, topping, and defoliation. However, doing so too late will cause a great amount of stress causing them to become stunted and slow down flower production. Avoid doing any type of plant training techniques after day 28 and allow the plants to grow and flower.

9. Short Lighting Hours

The ideal lighting schedule for indoor autos will be to set the timer to 18/6 or 20/4. The more intense lighting they can get will set them up to become bushy and tall. Avoid using a short lighting regime such as 12/12, otherwise they will not have the time to be productive. It is a good idea to plant many auto-flowering plants in the same growing space, and the Sea of Green setup is an excellent and simple way to achieve proper yields with little maintenance. 

10. Low Quality Genetics

Working with top-quality genetics from a reputable seed bank will guarantee that you are halfway to achieving great results come harvest time. Growers who want to save money and choose cheaper seeds from a local grow shop or unknown seed company will most likely be growing out low quality auto-flowering seeds. 

Even if you give your autos the right nutrients and the indoor environment is on point, genetics will always let you down. So make sure you spend your money wisely and do not try to cut corners. Always use a well-known source and buy directly from an industry-renowned seedbank who you can always contact directly in the event of any issues or problems later down the line!

My Final Thoughts

When you can provide your indoor autos with the perfect amount of light, water, nutrients, pot size, temperature, humidity, and intense lighting, then there is no reason they will not grow into superb plants. We all make mistakes as an indoor grower, and learning from them is the key to success. Good luck growing the best auto-flowering crop possible and finding out what cannabis plants need to flourish and keep your jars full of amazing flowers.

Also read on Soft Secrets:

• 10 Top Tips for Harvesting Cannabis Indoors

• The Differences Between S.O.G and S.C.R.O.G

• The Importance of Plant Auxins in Cannabis Growing