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powdery mildew cannabis treatment

Powdery mildew cannabis treatment

  • sulphur
  • copper
  • synthetic fungicides and all other products not suitable for agricultural crops
  • fungicides that will desiccate the leaves or flowers such as horticultural oils and salts
  • choose cannabis strains with a high resistance if you live in an area prone to mildew infestation
  • ensure a good climate in the greenhouse and indoor (ventilation, electric or gas heating required)
  • avoid the use of nitrogen-rich manure (like fresh manure or unripe compost), avoid fertilizers high in ammoniacal nitrogen such as pure guano in powder and pellet form
  • prevent white fly and aphid infestations and treat plants thoroughly if diseased, the sticky secretions from these pests cover the leaves and facilitate mildew which in some cases turns greyish-black
  • do not grow too close to damp areas (riverside, etc.)
  • increase the light intensity indoor if you are growing under low-light (such as CFL, fluorescents, LED lamps, etc.)
  • use garlic teas and garlic sprays
  • treat plants regularly with lecithin-based sprays
  • remove or treat all infested weeds and ornamental plants on your property; cut away infested twigs on fruit trees at the earliest signs of infestation
  • spray down leaves with clean, chlorine-free water if they are covered in pollen after pollinating buds for seeds (wait a few days after pollination is completed), stale pollen residues easily turn moldy under high humidity and attract mildew

To begin with, it’s important to distinguish the criteria according to which fungicides for organic produce intended for human consumption should be purchased. These criteria ensure not only safety measures for humans, but also for the environment: such as for beneficial insects, animals, and aquatic life. Secondly, the fungicide must be safe to use on a soft-leafed plant species such as cannabis and flowering plants in general (if required for the flowering period). Therefore, the first step when purchasing a fungicide is to check the product information on potential hazards for specific plant species or flowering plants, human consumption, and the environment.

Powdery mildew is one of the most widespread plant pests. It tends to affect flowering plants and fruit trees or bushes (roses, apple trees, etc.) as well as cannabis. The spores are in the air or on contaminated plants in the garden and can easily be drawn into your grow room by ventilators. In internet forums and cannabis cultivation books you may find lengthy lists of possible treatments that look temptingly promising for a complete recovery at all stages of mildew infestation. But the authors have rarely tested these products themselves, and the compounds are seldom differentiated between those applicable only for growth, and those also safe to use during flowering. This guide is therefore specifically orientated towards publishing some first-hand experiences with a variety of fungicides, and a review on the specific utilisation of products during growth and flowering in cannabis plants.
We have tested several products available on the market in Europe as well as easy to use home-based recipes. One of the most promising are lecithin-based products. Commercial products based on lecithin have become very useful tools in powdery mildew control in central Europe since the product does not cause any off-flavours. It is also harmless to fragile young plants and, most importantly, to flowering marijuana buds.
In North America the ECO SMART Garden Fungicide is one such product:
Powdery mildew can be detected by the white-coating on leaves and shoot tips, which succumb to the infestation by atrophy and eventually die. Only the surface of the leaves is contaminated by the fungus. Very heavily infested plants often cannot be saved. Plants affected by this disease and wilting plants should be removed from the garden if you don’t want the spores to spread. If the infestation of powdery mildew arises during the last few weeks of flowering it is possible to control an infestation until harvest. A good fungicide can fully combat powdery mildew, but the treatment is often lengthy and takes several weeks. Mother plants and cuttings should be treated preventively so that valuable genetics are not lost.
Is milk the answer?

Garlic is cheap and readily available. This has made it a favourite “home-grown” pest control, especially among organic gardeners. The volatile antimicrobial substance allicin (diallylthiosulphinate) is produced in garlic when the tissues are damaged during crushing or chopping the garlic. Allicin in garlic juice inhibits the germination of sporangia (in which the spores develop) and thereby acts as a fungicide. You can buy readymade garlic extracts that are very effective in three ways: as a natural insect repellent, as a fungicide, and plant strengthener. Alternatively, you can make your own juice by using a homemade recipe. Garlic extracts are not suitable for seedlings and should not be applied under direct sunlight.
Garlic GP Ornamental Fungicide is a commercial product available in North America.

Knotweed extract induces phytoalexins which infer resistance to powdery mildew and other diseases such as Botrytis. In other words, the extract helps the plant fight the mold rather than attacking the mold directly. We have not tested knotweed products yet and therefore the information presented here is only based upon scientific studies on a variety of other plant species. However, these results do indicate promising effectiveness for cannabis too since a large variety of cultivars respond favourably to the treatment.
There are two primary products on the market: Milsana® and Regalia®. Milsana® is available in Europe. The technical grade active ingredient (TGAI) consists entirely of the dried and ground plant material from harvested Giant knotweed plants grown for this purpose. The end-use product Milsana® is classified as a “Bioprotectant concentrate”. It contains 5% of the ethanolic extract of Reynoutria sachalinensis. Milsana® is recommended as a spray on greenhouse grown plants for the purpose of boosting their natural defence mechanisms against certain fungal diseases. The product should be used as a preventive application mainly for the control of powdery mildew and is used for vegetable and fruit plants in Europe for outdoor/greenhouse cultures. No unreasonable adverse effects on humans or the environment are anticipated from exposure to Milsana®.

Prevention and treatment of powdery mildew on cannabis and marijuana. Mandala Seeds ensure plant resistance is maintained or optimally enhanced

Powdery mildew cannabis treatment

Powdery mildew plagues cannabis plants in any setup. Oftentimes, it lowers the defenses of the crop which makes them more vulnerable to other pests and diseases. At wort, it can result to very little to no harvest at all. So, learn how to control this problem before it devastates the entire crop.

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As mentioned, the best way to deal with powdery mildew is to stop it even before it happens. So, here are the methods that guarantee mold-free marijuana plants.

To stop the infection from spreading, we must remove severely infected marijuana leaves. When doing this, it’s important to contain the infection as much as possible. Hence, a plastic bag is useful when collecting the leaves.
One way to get rid of powdery mildew is by using a popular homemade mix. Simply combine 2 teaspoons of apple cider vinegar and a quart water in a bottle spray. Then, mist the mixture on the leaves to stop fungi from growing. We can also use this as a preventive method.
But where does it comes from? Spores that freely float on the wind through the ventilation system, pets, or any other living things are the culprits. Basically, they will stay dormant on any surface then emerge once the environment becomes ideal for them.
As mentioned, powdery mildew thrives in crowded and confined places. So, make sure to provide an extra space for the plant when transplanting them into their mature location.
One of the hallmarks of powdery mildew is its appearance. Usually, it is white and creates a bold contrast with the marijuana leaves. Since they come from spores, we can’s see them as they spread in the grow room. Hence, it’s extremely tough to prevent them.

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Powdery mildew is a nasty condition that affects marijuana plants and result in a devastating harvest. So, learn to prevent and control it in a few simple steps.