best organic nutrients for autoflower

Growing Autoflowering Cannabis Plants Using Organic Fertilizers

There is nothing more rewarding than growing your very own organic medicine, in the comfort of your own home. If you are planting indoor or outdoors, using organic nutrients is a green and eco-friendly way to grow your own medicine.

In this article, we explain all about growing autoflowering Cannabis using organic methods, boosters for the growing and flowering stages, and the importance of flushing.

1. From Seed To Harvest

Autoflowering Cannabis plants have the ability to be planted and harvested between 9-10 weeks. Regardless of the amount of lighting the plants receive, they will begin to start flowering after a 21-day period.

From this point onwards, the plants will focus on transitioning into flower, meaning they will stretch in height and start to produce resin-coated buds.

2. What Nutrients Do Autos Need?

Primary Nutrients

These consist of the three main nutrients an autoflowering Cannabis plant will use during its lifecycle. Nitrogen, Phosphorus, and Potassium are essential in the development of root growth, stem, leaf, and flower production. These are responsible for the production of hormones, proteins, vitamins, and chlorophyll production.

Secondary Nutrients

Magnesium, Sulphur, and Calcium are classed as secondary nutrients and will be used in combination with primary nutrients and trace elements. They are very important and play a huge role in the metabolism and cell function of Cannabis plants.

Trace Elements

These are essential to the balance of the plant health and should be used in conjunction with primary and secondary nutrients.

3. Organic Nutrients For Cannabis Plants

If you have chosen to buy the nutrients and soil from an existing brand, then you will have everything that you need between the soil, and bottled nutrients to cover the plant’s requirements. For beginner growers, following an organic feeding chart is an excellent way to grow Cannabis plants, without the need for any advanced skill level.

For those who wish to take organic growing to another level, using living soils, homemade compost and worm castings and aerated compost tea will allow Cannabis plants to grow with incredible vigor, plant health, and with a superb resistance, as well as enhancing the flavor and aroma of the flower even further.

4. Organic Boosters For Flowering

As the flowering period of an autoflowering cultivar can last from 6-7 weeks, it is important to supplement the plants with higher amounts of Phosphorus and Potassium than before. Nitrogen is not as essential and can be cut out during the final half of the blooming period.


• Used for root development and flower production.

• Aids in energy transfer and photosynthesis.

• Necessary for resin production.

• Essential for seed production.


• Responsible for combining starches and carbohydrates.

• Aids in chlorophyll production.

• Helps regulate the stomata function responsible for CO2.

• Increases oil content and flavor profile.

Molasses Based Nutrients

• These will be thick and dense with a dark brown, caramel shiny appearance.

• Packed full of minerals and rich in Potassium.

• A rich source of sugar for the microbial soil life.

• Used normally to add weight to the plants during flowering.

5. Bat Guano

A very popular choice for growers who are aware of the benefits associated with using bat guano in power form, as a pre-made extract or in the form of an aerated tea. Nutrient companies will source their guano from all over the world ranging from Indonesia, Jamaica, Spain, and many other places.

Depending on the diet and where the bats are located, and the time the dried guano is harvested the bat caves can determine the N-P-K value. Normally bat guano is high in Phosphorus and will act as an excellent nutrient to feed plants during the blooming period.

The Benefits Associated

• Flavor is dramatically enhanced.

• Bat guano is rich in enzymes and beneficial bacteria.

• Can be used in powder form and mixed into a growing medium.

• Aerated bat guano teas are superb for stimulating flower production.

• The aroma and terpene production will become more advanced.

6. What About Flushing With Organics?

If you have been using any type of nutrients apart from watering soil, then you will need to flush your autoflowering plants. One of the main reasons is to encourage your flowering ladies to push and use up all of their internal reserves, and the other is to flush out your growing medium.

Over the 10-week period, there will have been lots of nutrient solution in the form of undissolved salt minerals that need to be cleanly removed. Water is essentially a solvent and by using only pH-adjusted water, for the final 14 days prior to the harvest date then you will have cleaned out the growing medium, and encouraged a final growth spurt from your plants.

7. In Conclusion

Growing Cannabis using organic methods is a great way to learn about how autoflowering plants grow, the ideal watering frequency, and to obtain the best flavor possible.

Follow simple instructions and in some cases simply add only water, Autoflowering cultivars are so resilient and can adapt well to any climate, so provide them with the ultimate organic nutrition and they will do the rest for you.

There is nothing more rewarding than growing your very own organic medicine, in the comfort of your own home. If you are planting indoor or outdoors, using orga

Best Feeding Schedule for Autoflowering Plants

All autoflowering cannabis plants , like any other plant, need nutrients to stay alive and grow. Plant nutrients are divided into Macro and Micro. Macronutrients are nutrients plants use in large quantities: Nitrogen (N), Phosphorus (P), and Potassium (K). Micronutrients are the secondary elements and are absorbed in much smaller amounts: Magnesium (Mg), Calcium (Ca), Sulfur (Su), Copper (Cu), Zinc (Zn), Iron (Fe), Manganese (Mn) among others.

Both macro and micronutrients are delivered by watering with mixed nutrients, pre-amended soil, or slow-release powder, when feeding, remember that you can always add more but never take away nutrients.

It’s easy to over or underfeed and damage your plant, that’s why we recommend following the best nutrient schedule for autoflowers, specially designed for autos.

  • Week 1 Seedling – Plain water;
  • Week 2 Vegetating – ⅛ veg. nutes;
  • Week 3 Vegetating – ¼ veg. nutes;
  • Week 4 Pre-flowering – ½ veg. nutes;
  • Week 5 First signs of flowers – ¼ bloom + ⅛ veg. nutes;
  • Week 6 Flowering – ½ bloom nutes;
  • Week 7 Flowering – ½ bloom nutes;
  • Week 8 Flowering & ripening – Flush;
  • Week 9 Ripening & harvest – Flush;

1. Different Types of Nutrients

Nutrients can come in different forms. The most common are diluted in water, mixed with soil, and in powder form to be used as a slow-release top dressing or to be mixed with the medium. Usually, beginner growers ask What are the best nutrients? That will depend on your preference and method of growing, there are basically two types: organic and inorganic nutrients and there’s a big difference between them, both of them can come in the three different forms we talked above but work in completely different ways.

Organic vs Inorganic

Organic focuses on creating and maintaining a rich medium filled with microorganisms. By using organic nutrients you’re not feeding the plant directly, you are enriching the medium where microorganisms present to feed on the nutrients, breaking them down and making it easy for the plant to absorb.

Because you’re not feeding the plant directly, she can decide when and which nutrients to absorb so unless you do it on purpose, it’s really hard to have problems related to an excess or lack of nutrients.

Inorganic nutrients work by delivering an exact amount of nutrients to the roots. To be able to do this without any damage to your plant you must really know the necessities of your autoflower. The nutrients needed for optimal growth vary from strain to strain so it’s really hard to know exactly what and when to feed. Usually, you start experimenting and if you see signs of underdevelopment or deficiencies you feed a little bit more.

On top of that, you will have to adjust the amount given to an autoflower to avoid wasting nutrients (organic) and to avoid burning your plants (inorganic). Manufacturers usually make available instructions with an approximate schedule and amounts for the products they sell but they usually are directed to photoperiodic plants. Having that in mind, we recommend always starting with half the recommended amount with autoflowers.


Slow-release nutrients can come in pellets or in powder form. Usually used as a top dressing or pre-mixed with soil, this is the simplest way of feeding because it slowly releases nutrients when watering. So you don’t have to worry about feeding your plant until harvest unless you see any signs of deficiency.

The best way to water when using slow-release feeding is water more often with less water, this way the pellets or powder will dissolve faster and you won’t have any problems.

This way of feeding also comes with instructions directed for photoperiodic plants so with autoflowers you should (generally) use half of the recommended amount.

Tip: This way of feeding takes a couple of days to dissolve the pellets or powder if you water every couple of days. If you see signs of deficiency or you notice your autoflower is hungry, you can use a small amount of water-soluble nutrients to fix this immediately and give the slow-release nutrients a bit more time to dissolve.

Bottled nutrients

Bottled nutrients are what everybody knows, grower, or not. These fertilizers come in liquid form and are usually synthetic, and relatively cheap due to the wide selection available.

Synthetic nutrients are popular amongst all types of growers, even though they’re not s safe as organic nutrients, you can effectively grow and harvest your plants without major problems.

You can find a lot of different brands and their quality may differ but all fertilizers will contain basically the same elements and ratio for the vegetative (3-1-2) and the blooming stage (1-2-3), so it’s just a matter of preference.

Have in mind that unlike organic feeding which focuses in creating an ecosystem in the soil, synthetic nutrients feed the roots directly so you can easily burn your autos, you should always start with a smaller dose and increase it gradually, this way you can check the signs your plant gives you and can adjust the amount of nutrients to your plant’s needs, avoid wasting nutrients and most importantly, avoid burning your plants.

Remember that because these nutrients are synthetic they’ll most likely kill the microorganisms present in the soil so (depending on the medium) you’ll have to provide all the micronutrients too, like Calcium and Magnesium, for example.

We recommend using organic nutrients when possible, this way you’ll be maintaining an ecosystem similar to what you find in nature, resulting in better tasting flowers and avoid overfeeding your autos.

2. Nutrients for the Seedling Stage

The seedling sprouts with two little leaves called Cotyledons. These leaves provide what the plant needs to survive until the first set of true leaves appear. The first two weeks of cannabis growth are the most crucial because the little seedling is establishing its root system and it is very fragile.

When to start feeding?

If you’re feeding in the seedling stage you must be very careful not to overfeed. You can start your autoflower with 1/8 of the recommended nutrients or better yet, just give the plant water for that first couple of weeks. If you overfeed your plant at this stage of growth it is highly possible that the baby plant won’t survive or if it manages to survive then the overall yield of the damaged autoflower will be greatly diminished.

Tip: Water-soluble feeding gives the plant access to the nutrients immediately.

If you are using mediums with added nutrients then you don’t need to feed the plant for the first 2-3 weeks (until the pre-flowering stage). So you can relax and forget about those nutrients at this stage of its growth.

Tip: Always read the recommendations as amended mediums contain different amounts of nutrients. Some may have the amount needed for the first weeks but others can have the amount needed up to the pre-flowering stage.

3. Nutrients for the Vegetative Stage

Photoperiodic cannabis plants have a vegetative growth stage but autoflower plants go from the seedling phase straight to flowering without the need to change the light cycle .

Some growers believe that the time when the little seedling gets its true set of leaves until it starts flowering is the vegetative growth stage for autoflowers. But it really doesn’t matter how we call this stage because we need to feed it just like a regular photo-sensitive plant in its vegetative stage.

When we see that our autoflower plant starts to grow fast we need to start giving it more nutrients. Usually, it is best to give half of the recommended dose of nutrients, but if the plant gets really bushy you can give it a full dose.

At the vegetative stage, cannabis needs a lot of Nitrogen (N) and a decent amount of phosphorus (P) and potassium (K).

No matter what the percentage of the other nutrients is, just make sure that Nitrogen (N) is available more than those other two elements. Autoflower cannabis also needs those secondary nutrients but commercial fertilizers usually have a mix of the other nutrients your plant needs in the solution.

4. Nutrients for the Pre-Flowering and Flowering Stage

After a couple of weeks in the vegetative stage, your auto will be mature enough to start developing flowers, when this happens your plants will start to develop pistils, which are a sign that your plant is entering the pre-flowering stage.

When to switch to bloom nutes?

When the first pre-flowers start to appear you need to change your feeding to a mix of half vegetative and half blooming nutrients. You need to slowly start introducing more Phosphorus (P) and Potassium (K).

Phosphorus is essential for bud production and has to be available when your autoflower enters the flowering stage. Once your autoflower starts really producing bud you should start feeding only blooming nutrients.

Some growers think that you must strictly go by the schedule when you are feeding your plants and if you don’t change your fertilizer your plant will not grow properly.

But the truth is that almost any fertilizer will do just fine. You can be very precise and if you have a lot of experience you can boost your yield with appropriate fertilizers but for beginners and medium level autoflower growers it is not as crucial. It is always best to give your plants less food than overfeed them.

5. Autoflower Nutrient Schedule

Cannabis plants don’t like to be overfed and they can easily get burned because of that, the amount needed for an autoflower depends on the strain and growing environment. The following schedule should be adjusted depending on when your plant starts flowering.

Chart for inert mediums

Week Stage Nutrients
1 Seedling Water
2 Vegetative stage ⅛ vegetative nutrients
3 Vegetative stage ¼ vegetative nutrients
4 Pre-flowering stage ½ Vegetative nutrients
5 First signs of flowers ¼ bloom + ⅛ vegetative nutrients
6 Flowering stage ½ bloom nutrients
7 Flowering stage ½ bloom nutrients
8 Flowering & ripening Flush
9 Ripening & harvest Flush

Have in mind that more nutrients does not result in more growth, some plants are more sensitive to nutrients. Overfeeding your autoflowers can affect your harvest because they will need time to recover and when this happens (especially in the flowering stage), it can take up to 7 days for them to recover and continue growing normally.

Note: This schedule is based on amounts recommended for photoperiodic plants, that’s why we use ½, ¼, and ⅛ amounts. If you were to use a medium with pre-added nutrients, then you should only water until you see signs of pre-flowering (around week 4) and only then start feeding following this schedule starting from the Pre-flowering stage.

6. Nutrient overfeeding

Overfeeding is the result of a too strong solution, as said above, more nutrients don’t always result in more growth and some plants are more sensitive than others.

When you don’t measure the dose of nutrients that go in your solution, you can overfeed your plants and they will surely show signs of deficiencies. Even though it’s a common problem amongst growers, the problems that come along are really serious and can end up killing your plants.

Signs of overfeeding are yellowing or yellow spots on the leaves and can be more serious if you don’t fix it, if you continue to feed a strong solution the leaves will start to brown, get crispy and die, this results in a stressed plant which will grow slower, can end up producing lower yields and ultimately die, so if you see signs of deficiencies you should flush right away, give your plant a couple of days to recover and start feeding again with a lower dose.

Have in mind that you can easily avoid this by using our feeding schedule above or just by simply using a lower dose than recommended and increase it gradually.

7. Nutrient underfeeding

Underfeeding can also hurt your plants, if you fail to provide the nutrients your autos need to produce sugars they won’t be able to grow and will show signs similar to the symptoms of overfeeding. Even though some plants can grow well without nutrients, it’s recommended you provide at least a minimum amount to make sure your harvest meets your expectations.

Remember that nutrients are extremely important so even though you may be afraid of overfeeding your plants, there’s no need to be, it’s normal for beginner growers to burn plants, even more experienced growers can burn plants when they’re trying a new nutrient brand so don’t worry.

Just make sure you learn with your mistakes and try to adjust the dose until you reach the optimal amount.

8. Flushing and when to stop feeding

Flushing consists of washing the excess nutrients from the roots and medium 1-3 weeks before harvesting. As you may know, all cannabis plants absorb nutrients to grow, when a plant absorbs nutrients there can be a nutrient build-up, although this is more common with synthetic nutrients, it can also happen with organic nutes.

Failing to flush properly can easily affect your buds, usually, plants which have not been flushed have a less potent smell and are harsher to the throat so if you want the flavor and smell of your buds to stand out, and a smoother smoke, we recommend flushing with plain water or flushing products which can be found in grow shops.

9. In Conclusion

Not only autoflowers but all plants are different in one way or another. You can follow schedules like the one we provided above but the optimal way to feed your plants is by understanding the environment you’re growing in and the cultivar you’re growing.

Our Purple Lemonade, for example, is a sturdy grower and will do perfectly fine without nutrients.

Usually, nutrients come with instructions for photoperiodic plants, learn how to adjust it with the best auto feeding schedule.