1. Nutrient Schedule For Autoflower

1. What are the best nutrients for autoflowers?

Find Advanced Nutrient feeding schedules and charts here. Advanced Nutrients are our favorite nutrient line for growing cannabis and other cash crops. Because they have so many products, it can be hard to decide where to start, even for seasoned pros. I will be starting a hydroponic grow of auto flowering plants (2), and plan on using the FloraDuo A+B nutrients. I've been reading up on the auto flowering process, but one thing I seem unable to find is a proper feeding schedule, as auto flowers take less time.

Why give autoflowers nutrients? All plants use photosynthesis to synthesize food from carbon dioxide and water. However other elements are essential to ensure sufficient photosynthesis can take place. The three major elements are Nitrogen (N), Phosphorous (P) and Potassium(K) but also necessary are sulpher, calcium and magnesium. These are present in the ground surface worldwide, but a deficiency of any of these elements leads to poorer growth, less root development and inconsequential flowering. Climb any scrub land wasteland along the Mediterranean and you’ll find wild lavender: but its not a plant you’d find desirable in your garden. Partly this is down to genetics (plant nurseries have over generations selected varieties with bigger and bluer flowers and more scent) but its also down to the levels of basic nutrients in the poor soil.

Walk around any garden center and you’ll spot plant fertilizers specific to a type of plant (rose nutrients, bedding plants feeds, tomato feed, shrub and tree fertilizer). Why is this? Because different types of plants have different demands both in regard to the potency of their nutrient additive (bedding plants grow fast within one season and you then want them to flower prolifically, whereas shrubs and trees produce slow growth over many years) and also the ratio of N:P:K. Nitrogen is generally associated with vegetative growth, Phosphorous with root growth and flowering, and Potassium with the overall vigor of the plant.You can see that different plant types will demand these elements – and the minor ones – in different proportions both according to plant type, but also to the stage of life-cycle the plant is at.There’s a huge industry aimed solely at providing cannabis growers with the best nutrients for their plants, to improve health, vitality, growth. and of course bud production. There are variances available so that whichever growth medium you are using, the nutes will enable your plants to perform at maximum potential. Its my opinion that there’s no one “best cannabis nutrient” as all the major – and some of the minor – cannabis feed producers will have spent years in research and development. In fact its probably more down to what nutrient regime works best for you and your set-up (but if pushed I would admit to using Canna as my main brand of nutes).

2. Do autoflowers a different type of nutes to the brand I use for my “normal” cannabis?

No – you can use the brand you are comfortable with. There are a very few one part all-purpose seedling to harvest feeds being marketed as specifically an autoflower nutrient. These are

2. Why does autoflowering cannabis need a different nutrient schedule?

• Growth rates of autoflowering strains are highly accelerated.

Germinate 10 seeds at the same time, 5 of autoflowering varieties and 5 of photoperiod strains, and compare the developmental difference at 2 weeks. The autoflowering plants will be at least twice the size of the other plants, and well onto their 3rd or 4th nodal growth. That’s just as well, because in 5 days or so they will be making the switch to flowering whilst your standard strain seeds are still flimsy seedlings.The logical response to this fast growth is to increase nutrients, and feed the plants according to their development rather than their age. After all, a plant that grows that fast must use lots of nutes, right? – Nope:

• All autoflowering cannabis strains contain a high genetic proportion of cannabis ruderalis

The genetic trait of Cannabis ruderalis is to flower according to plant age rather than according to the light cycle. All autoflowering strains will have an element of ruderalis bred in: its what gives an otherwise photoperiod strain its autoflowering ability, and because ruderalis strains are non-psychoactive (and therefore until recently uninteresting to cannabis seed breeders) breeders use plants only one or two generations away from wild ruderalis strains. These have lower nutrient requirements than the strains we are used to growing, and it’s easy to over fertilize an autoflowering cannabis plant.

• Get it wrong and you’ve no chance to make good a mistake.

When you grow a photoperiod plant, if you over or under feed her, you can diagnose and correct your error. In the indoor grow room, if your plants are showing signs of a particular deficiency, you delay flipping into flower until new growth is green and the plant looks healthy again. An outdoor cannabis grow gives you several months of vegetative growth in which to dial in the correct feeding regime for that strain. An autoflower grow gives you no such tolerance. By week 3 or 4 flowering has begun, and if your plant is showing signs of overfeeding, nutrient deficiency or some other imbalance, the lack of growth caused by that mistake is irretrievable. Yes, you can alter your nutrient regime to prevent further damage but you cannot get that lost growth back.

This is the major reason why some cannabis growers think autoflowers are not worth the time and resources used to grow them. A small plant with low yield is not the fault of the strain but rather its due to grower error. You can expect 50-100g from most autoflowers if you get the nutrient schedule right.

Read on for advice on the nutrient schedule for your autoflowers:

Nutrients for autoflower seedlings:

Cannabis seedlings really don’t need any nutrients. Their fragile first developments of a root system are vulnerable to nutrient burn and anyway these tiny plants have no use for additional nutes anyway so it’s not worth the risk of damaging them at this stage: pHd water should be sufficient for all the autoflowering seedlings needs. However, if your young plants start showing signs of underfeeding (yellowing leaves) you can use something like Canna Start which has been specifically formulated for cannabis seedlings:

Nutrient Schedule For Autoflower

In short, leave off adding any nutrients until the 4th node (set of true leaves) has developed!

Nutrients for the vegetative/growth stage in autoflowers.

Choose your medium carefully:

When it comes to potting on our autoflower seedlings, we prefer using a Light Mix Soil as this isn’t pre-loaded with nutrients and makes a good base from which to gently add the nutrients as our plants need them. Alternatively, you can use a neutral base such as a coco/perlite mix. Strictly speaking, autoflowers don’t have a vegetative stage: once the seedling stage has passed, autos are almost instantly making the switch into flowering.

However, its important to give them sufficient minerals to ensure that they grow as big as possible within this time frame. Veg stage nutrients typically have an N:P:K ratio of 3:1:3 (Canna’s Terra Vega) or 10:5:5 – whichever brand you’re using, a vegetative stage nutrient will have nitrogen as its main component, as this is necessary for strong leaf and stem growth. From around day 10 start including a veg feed but start with 1/4 the recommended dilution rate and build up to half strength food. Your autoflowers will need the nitrogen for the fast leaf development but the ruderalis component will suffer from full strength feeding. You can use a root booster such as Rhizotonic to encourage strong root development.Now, here’s where we differ from some autoflowering grow advice:

> Continue with veg feed after flowering starts.

The first 10 days of flowering – known as “pre-flower stretch” – describes the accelerated vegetative growth that happens when you put a photoperiod strain into flower by changing the light cycle. During this period, plants can increase in size by 30%. An autoflower strain will only have had a very short growth period and by giving it a higher percentage of nitrogen right up until the point when flowering is set you enable her to maximize her vertical growth and thus ultimately increase the potential for greater yields. A plant that grows 25% taller thanks to continued high nitrogen during early flowering will always have the potential to produce more bud.

Best Nutrient Regime for Big Buds on Autoflowers!

Switching to a high Phosphorous ratio flowering nutrient (look for 2:2:4 Terra Flores or similar) means your plants will get the phosphorous they need to produce bigger, heavier flowers. If you stayed with a high nitrogen feed in bloom your plants would continue to develop lots of leaves alongside the buds – and dividing the plant’s energies in this way results in lower end results.Again, start on 1/4 strength recommended dilution rate and gradually increase the feed as you are sure the plants can take it.Because of autos sensitivity to over feeding, we wouldn’t really recommend using the specialist bud-boosting additives such as PK13-14 or Canna Boost Accelerator. You’re much better off keeping to a simple nutrient feeding regime and producing healthy, productive plants than dealing with issues caused by complicated additives.

Remember to flush your autoflowers.

As with all cannabis crops, a good “flush” – using pHd water only – for the final 7-10 days of flowering rinses out chemical residues of the nutrients and results in a cleaner, purer hit. Full strength Cannazym can be used during this time as it breaks down dead material in the root ball – this material is absorbed as sugars by the plant and makes a sweeter high.

The most common failing when first growing autos is nutrient overload.

Look for signs of over-feeding – yellowing or browning tips at the end of leaves. These tips are dry and crispy and crumble like a nearly burnt paper: but its not heat or light that have burnt your plants, its an overdose of nutrients, and is commonly known as nutrient burn. If you continue feeding at this level the “burn” will spread along the whole leaf, reducing overall leaf mass. Less leaves mean less potential to convert light to the energy needed to grow and produce buds.The situation gets even more complicated than this: if you continue to give your plants more nutrients than they can use (and autoflowers like light feeding remember) these minerals are left in the soil creating a salt build-up. The pH of the soil increases and the mineral salts build-up actually prevents new nutrients from reaching the roots. This nutrient lockout often manifests as a feed deficiency when actually the true cause is the reverse. Treat by flushing the soil through several times with pH plain water to wash the excess nutes away.

Grow organically.

An organic grow in a well aerated living organic soil, using organic cannabis nutrients or additives, is one way to avoid the problem of overfeeding. Organic nutrients, being natural, are less harsh for the sensitive autoflowering cannabis plant to absorb. Also, the end result, while possibly lacking the dense weight of a non-organic grow, will be smoother and more flavorsome.

In summary:

Its important to provide autoflowers with good cannabis nutrients: however experienced growers’ concerns about how to feed their autos are unfounded. Keep it simple, keep the feeding levels light and you’ll enjoy a successful autoflower harvest! Also read our 10 Top Tips for a Successful Autoflower Grow