How to Grow Weed Indoors Without Lights

Many growers believe that growing cannabis indoors can only happen as a high-tech operation. However, growing cannabis indoors doesn’t need to cost you a small fortune. Can you place a cannabis plant in a sunny window and let it grow? In short: Yes. Let’s discover how to grow cannabis indoors without purchasing expensive grow lights.

How to grow weed indoors without lights

Many cannabis hobbyists and growers grow in tents, wooden closets, glass greenhouses, or any other enclosed space which offers them the correct amount of space and light. These indoor grow spaces come equipped with specialized lighting, humidity and temperature control systems, and in some cases, custom decontamination stations.

Indoor growing setups come in various sizes and can cost thousands of euros depending on the type of lighting and other growing equipment bought to grow indoors.

Many growers believe that growing cannabis indoors can only happen as a high-tech operation. However, growing cannabis indoors doesn’t need to cost you a small fortune. Can you place a cannabis plant in a sunny window and let it grow? In this article, we discover how to grow cannabis indoors and produce the best results without purchasing expensive grow lights.

Is your house a suitable environment for growing cannabis?

Your house’s environment is perfectly suitable and safe for growing cannabis plants. Your home offers your plants the same basics you enjoy – Oxygen, warmth, protection from natural elements and light.

Light, water, and carbon dioxide are essential for your cannabis’s photosynthesis. Photosynthesis is the process that plants use to create carbohydrates for themselves.

Cannabis can’t grow and stay alive without light, you can grow without having to purchase and install artificial lights, but you will need to place your indoor plants in a reasonable amount of natural light to help them grow.

Pros of growing indoors without lights

For many cannabis enthusiasts looking to grow cannabis, the following benefits will explain why growing indoors without lights is an attractive option.

1. Inexpensive

Growing without lights is cheaper than the expensive costs of buying a high-tech indoor setup.

High-quality lights are expensive – not only are the initial hardware costs heavy on your budget, but these lights have a heavy power consumption and require installing specialist rigging equipment. The price difference is astronomical when you compare high-quality lights to sunlight beaming through your window.

Growing without lights also means you don’t have to grow in a grow tent, making your initial setup fees even cheaper. Grow tents, exhaust systems and all the other required components can add up to a minimum of a few hundred euros.

Growing in an available room with lots of natural sunlight will help you to reduce your cost of growing cannabis to only having to purchase the following items:

  • Soil
  • Pots
  • Fertiliser
  • Seeds
  • Reverse osmosis or distilled water

2. Non-restrictive growing

Growing without artificial lighting or bulky tents can be very liberating. Sure, high-tech equipment will allow you to get the most out of your cannabis grow, but there’s no denying that choosing to install a high-tech grow room to grow your cannabis will consume a lot of the space in your room, emit large quantities of light and make unnecessary noise. Utilizing a high-tech grow operation can become a massive commitment.

A few cannabis plants situated on a windowsill become much less of an intrusion into your life. Apart from your plant’s smell and size when fully grown, your cannabis plants are no different from any typical house plant you may choose to grow.

When you choose to grow using simple methods, you’ll have much more time than constantly monitoring temperatures and humidity levels, adjusting lighting levels and tending to your indoor grow.

3. Simplicity

Growing cannabis without artificial lights is much simpler than growing it with lights. Less equipment, dedication and less power usage make growing indoors using natural light much simpler and more convenient.

Cons of growing indoors without lighting

Growing cannabis without artificial light is indeed simple and easy. However, there are a few downsides to choosing to grow indoors without artificial lighting. The following cons are what you can experience when you choose to grow without lights.

1. Stretching

Stretching is a problem you will face when growing indoors. It helps if you have a window that faces the perfect direction (south, southeast, or southwest) to ensure your plant receives an uninterrupted supply of sunlight.

Your plants stretch when they are unsatisfied with the amount of light they are receiving. When grown outdoors, plants stretch to rise above any obstructive canopy to find direct sunlight. 

When grown indoors, it’s not uncommon to find your plants pressed up against the glass of your window. If your plants stretch too much, they may fall over. Stretched plants can become tall and require more space.

2. You will need lots of natural light

To get a decently sized harvest while growing indoors without light. You’ll need large unobstructed southeast, south, or southwest-facing windows. Without large amounts of sunlight, growing cannabis without lights could become a difficult task.

3. Smaller harvests

Especially if you’re new to growing cannabis on a windowsill, don’t expect your plants to yield 750g/m². Depending on your strain and growing environment, you should expect a harvest size of roughly 28g per plant when using natural light indoors. If you get your seeds cheap (and you’re in luck, as we’re Europe’s cheapest), that can still be totally worth it. 

4. The smell of developing terpenes

Another con you may experience is the smell your cannabis plants will produce when they reach their flowering stage. Tents and exhaust systems help trap and remove the smell of developing terpenes. If you’re growing on a windowsill, the only way to clear your plant’s scent is to open the window.

5. Stealth issues

Nosy neighbours can see what’s growing there depending on where your windows face.

If this is the case, seriously consider how they will react if they spot your cannabis plants. 

6. Dedication

When you grow indoors without artificial lighting, you must move your plants in several situations. As the light is coming from one angle, your plants will lean toward it. You’ll have to turn them fairly regularly to keep them upright.

Cannabis plants are photoperiodic, meaning they will need periods in absolute darkness. When growing indoors, you must be able to darken the room you choose to grow in. You can do this by investing in blackout curtains and drawing them to place your plants in complete darkness. Another option is to move your plants into cupboards every night to ensure they get the correct amount of time without light.

When growing indoors, you might choose to “chase light”. You might start your plants in a position to get the morning sun and move them later to catch the afternoon sun; doing this will allow your plants to receive as much light as possible per day.

6 steps to growing indoors without artificial lights

Growing cannabis without the use of full-spectrum lighting is possible. Here is our step-by-step plan below to help you make your first indoor grow a success.

  • Select a suitable location
  • Choose a suitable variety
  • Select your pot
  • Choosing a cultivation medium
  • Plan the start
  • Temperature

Step 1: Select a suitable location

The first step to growing indoors with natural light is to find a sunny spot in front of the window, preferably on a windowsill in front of a window facing south. That’s where your plant will receive the most light.

If you choose to grow away from a windowsill, there is a good chance that your plants will receive too little sunlight and, as a result, will not grow and stretch. Without the correct amount of light, your plants will begin to stretch and grow too high and the branches will become thin. Stretching is not a stable basis for your plants to grow big buds which can ruin your harvest.

Step 2: Choose a suitable variety

Once you have found a suitable place to grow your plants, it is time to choose the correct variety of cannabis to grow. When growing without lighting, it’s a good idea to select a type of cannabis that flowers automatically and quickly, like an autoflower.

The advantage of using an autoflower is that, unlike a photoperiod cannabis strain. The autoflower will flower based on the age of the plant and not on seasonal change. This means your autoflower will always flower if your plants receive water and sunlight. Autoflowers are relatively small cannabis plants that are suitable for windowsill placement.

Autoflower vs photoperiod plants: what’s the difference?

Photoperiod plants must follow a specific light schedule, especially during flowering. Photoperiod plants need a minimum of 12 hours of complete darkness to induce the plant’s flowering phase and help trichome development during the flowering stage.

Compared to photoperiod plants, autoflowering plants begin to flower automatically based on their maturation. When they reach a particular age or stage of development, they flower, regardless of how much sunlight or darkness they receive. Autoflowering cannabis plants do not need 12 hours of complete darkness to flower. This means you can leave your autoflowering plants overnight without worrying about them.

Another reason choosing an autoflower is a good idea is the time required to grow and complete your harvest. Photoperiod plants require several months of your time and attention, whereas autoflowering plants complete their life cycles in as little as 49 to 56 days.

Want to grow an autoflower but need to decide which strain to grow? Here is a list of four essential autoflowering strains to grow.

1. Do-Si-Dos Auto

Do-Si-Dos is the child product of OG Kush x Girl Scout Cookies x Face-Off OG. This strain is easy to care for and packs a significant THC punch. Do-Si-Dos provides you with a relaxing high combined with mild euphoric effects. This strain will produce a consistent, high-quality yield and is easy to grow. 

2. Northern Lights Auto

Northern Lights Auto is an indica-dominated strain with a relaxing, euphoric, uplifting high. Northern Lights doesn’t grow rapidly and is a low-maintenance strain, perfect for beginner growers. 

3. Lemon Haze Auto

If indica is not your favourite, the Lemon Haze Auto strain is perfect good for indoor growing without lights. Lemon Haze is a sativa-dominant hybrid with an energizing “head” high, transporting you with a spicy herbal vibe. Lemon Haze has a flowering period of 55 to 65 days, which is relatively short for a sativa, and supplies growers with a medium yield. 

4. Big Bud Auto

Big Bud Auto is an indica-based hybrid from Skunk #1, Northern Lights and Afghan. Big Bud has a robust earthy tone with a hint of fruitiness. When consumed, it provides you with a lazy high and will give you a couch lock. And even indoors without artificial lights it will show off its sizeable buds! 

Step 3. Choose your pot

When looking at growing cannabis, you must choose a pot that meets at least two requirements.

Firstly, the pot must not let sunlight through as your plant’s roots are easily damaged by sunlight. It is best to choose a dark-coloured pot. 

Next, your pot must have drainage holes so that excess water can quickly drain. To help reduce water wastage, place a saucer under the pot so that you can collect excess water.

Step 4: Choosing a cultivation medium

Once you have chosen a pot, it is time to select a growing medium. To have successful indoor grow without using artificial light, you will need to choose airy soil that drains well and is nutritious. The best soil you can use is organic soil free from chemical additives.

Step 5: Plan the start of your grow

Planning the start of your grow is all down to timing. It is essential that during the vegetative phase of your plants, they receive at least 14 hours of light per day. If you live in the northern hemisphere, the best time to germinate and plant your seeds is at the end of April.

Step 6: Grow room temperature

In addition to sufficient sunlight, ensuring your indoor temperature is well-regulated is crucial. Your cannabis plants love warm environments, by maintaining a room temperature of 21°C is vital to complete a successful harvest.

Managing your expectations is essential, especially if this is your first attempt at home growing. Caring for and mastering the art of growing cannabis takes years of experience. Have you got any experience growing indoors without artificial lighting? Share your experience below!

Comments

1 thought on “How to Grow Weed Indoors Without Lights”

  1. 1st year grower, done 2 autos, and because of extreme temps in Spain this year, photos have been flowering for 2 weeks already 31st August today ) Maybe harvesting end September not crop-tober ? Anyway, just germinated and got 8 autos in soil and about 2 inches tall, question I have is it ok to leave them in un natural light , put blue screen on my LG tv so they get 3 extra hours b4 ‘bed’ = dark, is it ok to leave my LED lights on too even though they probably not in blue light spectrum ? Run shower for half an hour for humidity b4 I go to bed, then cloche them until 7am then follow sun round house with the just broken soil seedlings, never in direct sun.

Leave a Comment

Your email address will not be published. Required fields are marked *

Author

  • Author_profiles-WSS-Julien

    Julien

    Meet Julien, an esteemed horticulturist turned cannabis connoisseur. Born in Toulouse, Julien pens insightful pieces to demystify cannabis cultivation, focusing on eco-friendly practices and strain genetics. He’s a proud advocate of responsible and enjoyable cannabis use, and highly committed to educating the community.
    More about this author
Scroll to Top