For centuries, gardeners have had to deal with pests of many varieties. Whether they are birds, insects, mammals, or even other humans, cultivated plants seem to have a target on their backs. While humans don’t really eat raw cannabis, some pests certainly seem to like the taste. If left unchecked, an infestation can end up ruining your crop. At the same time, using harsh chemical products to repel the pests can be harmful to you later on. To avoid all that, we have compiled a list of some safe and effective repellents (and other safety precautions) to keep bugs away from your plants.
1. Only use sterilized soil or fertilizer. The problem with unsterilized soil is that it can contain the eggs or even larvae of some common marijuana pests. If you grow your marijuana in that soil, you will be in for a rude surprise when those eggs hatch or those larvae start to grow up. This is particularly bad for indoor growers because there are no natural predators inside your house.
2. Use natural predators. Of course, if you’re growing marijuana outdoors, you can make use of a few pest predators. Ladybugs are notoriously beneficial to have around your outdoor marijuana plants because they love to prey on larvae and other potential pests. You should also encourage birds to nest in the area because they often like to snack on some pernicious marijuana pests. Put out some bird houses or a bird feeder to get birds to come around. Just make sure that they stay away while the seeds are germinating because many birds do enjoy the taste of a marijuana seed. Download my free marijuana grow guide at this link and for more outdoor growing tips.
3. Grow companion plants. Interspersing the marijuana garden with a few naturally repellent plants is certainly a good way to keep the predators away. Although the THC that marijuana produces acts as a natural repellent in its own right, it is often not strong enough to repel all plants (especially in the early stages of life). Particularly pungent plants like geraniums and marigolds will keep many leaf-eating insects and worms at bay. You can even plant some onions to ward off bigger pests like deer or rabbits.
4. Use the urine of your pests’ enemies. This might sound like a joke, but it actually works and it’s actually feasible. Many mammals like deer have keen senses of smell and if they detect a hint of bear or puma urine, they will want to stay as far away from your marijuana plants as possible. That’s because they won’t want to enter territory that a much larger predator has been roaming around in. The same is true for rabbits and fox urine. You can buy these scents at many sporting goods or outdoor shops.
5. Build a fence. If bigger animals are a problem and the scent of their enemies doesn’t deter them, then you might need to try building a fence around your plants. Obviously, many marijuana growers don’t have this luxury and it’s really only something that people growing on private land can do.
6. Create a repellent force field around the plants. With a permethrin-based repellent, you can keep insects away from your plants without using the synthetic spray on the plants themselves. Simply spray a ring on the ground about 6 feet away from the plant. Any bugs that come into contact with the permethrin will die or just evacuate the area.
7. Use custom organic repellents. Many growers have opted for pungent, organic repellents to keep pests away from both their indoor and outdoor plants. Concoctions like cinnamon oil, clove oil, and coriander oil have all had relative success without causing any damage to the plant. You can easily spray these repellents directly onto the cannabis leaves with no fear of any adverse reaction. Of course, different cannabis strains might have different reactions to any homemade organic repellents, and you should always test the repellents on an inconspicuous section of the plant to make sure no harm is done.
All cannabis plants start as seeds, and they all require water to germinate properly. Each seed contains a full, little plant that has a root, stem, and a couple of leaves. There are also enough nutrients in the seed for it to survive the first portion of its life. During germination, these vital nutrients (proteins, carbs, etc.) are transformed into glucose, which all plants need to for growth.
1. Let the seeds soak in water that is 65°F (18°C) until they split open and roots appear
When seeds achieve a nice moistness level, they will enlarge and split open. A single root will grow downward with gravity out of that split. The root will always grow down no matter what and the stem will always grow up.
Placing your seeds in water ensures that they have achieved the proper moisture level for the process of germination to begin. The seeds will not take on excess water and drown until about 2 weeks after they have cracked open (you will have already transplanted them into soil by then).
When you fill your glass with water, simply put it in the living room so that it shifts to the temperature of the environment. Tap water is fine, but don’t give the seeds any extra nutrients because they already have everything they need. The seeds will crack open in between 2 and 7 days. Make sure to replenish the water in the glass every other day. Start transplanting when the roots reach 0.1 to 0.2 inches (3 to 5 mm) in length. Download my free marijuana grow guide to learn more about marijuana seeds at this link
2. Place your seeds in a ½-inch hole in small pots with seedling soil
The nutrient level of the seeds is already adequate, so you should use a soil with fewer nutrients to start. Soil made specifically for seedlings and clones that has low quantities of nutrients is ideal. Plants are very susceptible to nutrient burn at this stage if you give them too many nutrients.
The pots should be filled halfway with the seedling soil. To make the half-inch hole, use your finger tip or a pen. Each seed should have its own pot. Since the roots will always grow down, you don’t have to worry how you place the seeds in the soil.
Place the seed in the hole, and cover it up with the soil. When you spray the soil with water, it will tamp down on its own. Avoid pressing the soil. The germination process will continue until the plant starts to surface within a week. The taproot will produce other root offshoots so that the system is strong.
3. Use a plant sprayer to moisten the soil
Water is responsible for both life and germination, making it the most vital component early on. It is extremely important that you give the plants plenty of water and keep the soil moistened.
Plants that don’t receive enough water will compensate by not growing to full capacity. This is largely to increase the plants’ chances of survival. Of course, too much water can cause the plants to lose out on valuable oxygen. Leaves will start to wither and the marijuana plant and growth medium will become more susceptible to diseases and bacteria.
The soil needs to stay adequately moist (not too dry and not over-soaked). The seedling won’t use much water, but a lot of the water evaporates fast. This is the major reason why seedlings should never go on a windowsill or near a heater. Spraying the plants 1 or 2 times throughout the day should be plenty.
4. Put pots 2 inches below CFL tube
Other than water, light is another vital component for the plant’s growth. Light and water help convert carbon dioxide into oxygen and glucose—necessary resources for plant growth. This is referred to as photosynthesis.
When plants don’t receive adequate light, they will form fewer side branches and will elongate abnormally. This stretching helps marijuana plants grow taller to grab enough light in nature. Plants that receive adequate light will grow wider (not taller) and produce a flurry of side branches with a ton of buds. Light should be kept on 24 hours per day and the room should have a consistent temperature of around 72° Fahrenheit.
The pots should be placed under a cool white CFL light at a distance of 2 inches. These tubes don’t create that much heat, they’re energy efficient, and they use the ideal light spectrum for seedlings. Seedlings require about 3 to 5 watts each. When the plants surface after 5 to 10 days, they will need all the light they can get to grow optimally.
5. Moisten the soil with a water sprayer twice a day until seeds germinate
Creating the ideal climate is also important for germinating the seeds under ideal conditions. CFL tubes don’t produce that much heat, but they will keep the soil warm. You can keep the distance between the plants and the bulbs to a minimum, but if the temperature exceeds 77° F, then you should move them farther apart or cool down the area.
Soil moisture is important to ensure that the seed disposes of the water. Avoid feeding the seeds until the initial leaves make it through the soil. This happens after about 5 to 8 days. Be patient and just check the moisture level of your soil without feeding any nutrients.
6. First signs of the seeds
As soon as the seedlings pop their heads out of the soil, it’s vital to inspect the distance between the plant and the light. Adjust the lights if the temperature goes past 72° Fahrenheit or the leaves start receiving excessive light. The soil also needs to stay moist. The leaves on the plants can absorb water, so continue spraying them 2 times per day.
Again, this early stage in life makes the plants susceptible to damage from negative conditions. Don’t use a lot of nutrients and make sure the lights stay on 24 hours to produce a reliable climate. Avoid touching the plants and do not take away the seed skins from the leaves
The plants need to grow and develop sturdy root systems. Big green leaves are capable of absorbing ample light and converting it into energy. Healthy root systems allow plants to take in plenty of water and nutrients. The plant is just starting to form the base for the remainder of its life, so it’s important that they receive proper, diligent care.
7. First two internodes
When the initial internodes start to form, you can feed your plant with root-stimulating foliar nutrients. Start the plants off with a small dose as the developing roots can’t withstand higher concentrations just yet.
The plants will start to grow rapidly (about 0.5 inches per day). Inspect your plants each day for signs of nutrient surplus (e.g. burned leaf tips).
8. Transplant into bigger pots when roots grow out of the bottom
The roots will start to grow out of the bottom of your smaller pot at which point it’s time to transplant. The plant will become rootbound and stop growing if you do not transplant.
To recognize the roots, look for white tips poking out of the bottom. Check for the roots each day and start giving your plants grow stimulator, which is high in nitrogen. More about nutrients on this link.
9. Grow you plants outdoors or under MH/HPS lights
If everything went as planned, then you have strong, healthy plants that will eventually produce high yields. A good start in life means that the plants will be less susceptible to bacteria, diseases, pests, and the effects of harsh weather extremes. Plants that are healthy can better absorb water and nutrients and will develop a faster metabolism for better yields. If you email me a photo of your seedlings, I will publish them on my site.
These plants can now grow outdoors and will thrive in a wind-free location that gets a lot of sun. The plants will also do better in a big container (15 gallons) on a stool. This keeps away any interference from animals like rabbits or snails.
As you have seen, it’s not very hard to grow healthy marijuana plants. Everyone has their own technique and I’d like you to share your own knowledge on my forum. If you need high quality marijuana seeds, check out my seed shop for a wide selection strains at this link. The special offer for all Super Skunk, White Widow, and Super Silver Haze orders is still in effect (buy 5, get 5 free!). And we do ship to the States!
These are naturally occurring hyperparasites of powdery mildew. They form colonies on the infection, reducing growth and may eventually kill powdery mildew on cannabis leaves. Rain perpetuates the life cycle of this beneficial fungus. A formulated powder is available under the brand name AQ-10.
Bacillus Pumilus is a spore-bearing bacterium found in soil. It is resistant to environmental stresses, include UV light. The growth of Bacillus Pumilus on plant roots prevents Fusarium spores from germinating. A commercial product is available by the name of Sonata. Application boosts the cannabis plants’ immune system, inhibiting fungal germination and growth.
Bacillus Subtilis is a naturally occurring anti-fungal bacterium found in soils. It has proven to fight blight, gray mold and several strains of mildew, yet has no adverse affects on the environment or humans. For this reason, it has been approved as a fungicide and bactericide for use in organic farming. Bacillus Subtilis compounds prevents pathogens from colonizing crops. This biological fungicide can be procured online under several brand names. Two strains are available; one for foliage applications (QST 713) and one to be used as a soil amendment at the time of planting (GB03 or MBI600).
Barley Straw Rafts and Pellets
Barley straw rafts are used in hydroponic cannabis systems to inhibit the growth of algae. Barley straw does not kill existing algae but does prevent the growth of new algae cells. While barley straw has not been approved by the EPA for use in public waters, it is available for purchase by homeowners for hydroponics and private ponds.
The use of copper as a fungicide has been practiced for centuries. The most popular use today is in the form of Bordeaux Mixture, which combines copper sulfate with lime. The purpose of adding lime to copper sulfate is to reduce the damaging effect copper sulfate can have on marijuana plants. It is an added benefit that Bordeaux Mixture is also effective in controlling bacteria. As such, it is a good combatant for plant diseases caused by fungi and bacteria such as powdery mildew, downy mildew, leaf spots and fire blight. Bordeaux Mixture is a good option for controlling these diseases on outdoor grown marijuana plants, as it withstands rains, enabling its effect to remain on the foliage. However, it should only be applied before the flowering stage. Use a diluted solution on young plants to prevent burning of the tender leaves. Also avoid applying in temperatures over eighty five degrees to avoid the leaves yellowing and dropping off the plants. Follow label directions before using.
Gliocladium – Beneficial Fungus
Gliocladium is a species of parasitic fungus living in the soil. It produces volatile organic compounds which are toxic to other fungi and bacteria. Gliocladium protects Mary Jane from gray mold by suppressing spore production. It is best applied as a soil drench and is available under several brand names.
This common product found in drug stores and supermarkets, at 3% concentration, is a natural treatment for algae, gray mold, Pythium and powdery mildew. Using hydrogen peroxide on your marijuana plants will not bring them harm. Peroxide helps aerate the soil by adding oxygen and is both anti-fungal and anti-bacterial. Cannabis plants can be fed a mixture of hydrogen peroxide and water as a fertilizer and disease deterrent, resulting in healthy plants. It can be misted on the leaves and/or applied directly to the soil. An easy way to apply is to fill a clean fertilizer spray bottle that attaches to a garden hose and feed as you would, say Miracle Gro. The bottle will have gallon markings on it. Fill the bottle with peroxide. When you turn on the hose, it will automatically dilute. If feeding sick plants, add one cup 3% hydrogen peroxide per gallon of water. Pour into a spray bottle and spritz the leaves, making sure to cover completely. For general feeding, add one half cup to a gallon of water.
Hydrogen peroxide can also be added to the water in hydroponic environments. It can be used to sprout seeds by adding it to the water they soak in before planting; they will sprout quicker and grow stronger. Follow the general application recipe for the peroxide to water ratio if using to soak seeds.
Just as milk is essential to a healthy human diet by building the immune system and providing good bacteria to ward off infection, it works in much the same way for plants, including marijuana. Milk is a natural germicide and may boost plants’ immune systems in much the same way it does humans. It is a formidable treatment for powdery mildew. Applying weekly sprays of one part milk to nine parts water significantly reduces the presence of powdery mildew and will prevent it from forming if the plants are not currently affected. When rinsing empty milk bottles prior to putting in the recycle bin, pour the diluted milk around your plants rather than pour it down the drain. Your plants will love it!
Milk also acts as a disinfectant. Dip your gardening tools in milk, rather than bleach, when sterilizing between uses.
Neem oil is extracted from the nut of the neem tree, native to India. The insecticidal component of neem oil is azadirachtin which when applied, stops insects from feeding and developing. Neem oil is an effective defense against ants, aphids, fungus gnats, leaf miners, mealy bugs, scale, thrips, white flies and root weevils. Other components in neem oil have fungicidal properties combating gray mold, root rot, Septoria and powdery mildew.
The beauty of using neem oil in the cannabis garden is its low toxicity factor for humans, animals and the beneficial bugs you want to keep around. Neem oil is so safe for humans it is an ingredient in many household items such as toothpaste, shampoo and cosmetics. It is considered an organic control, will not harm the environment and can be found at local lawn and garden centers.
Neem oil can be applied as a foliar spray, soil drench and is safe to use in hydroponic systems. In the latter, apply one teaspoon per quart of water. The oil will be taken up by the root system and distributed throughout, protecting the plant from attack.
As a foliar spray, test an inconspicuous area of the marijuana plant before applying to the entire plant. Wait twenty four hours to see if it is well tolerated. Once confirmed, spray the leaves lightly. This should be done weekly until there is no longer evidence of pests or disease. Do not apply in extreme temperatures or during the day. Apply at night to allow the leaves to absorb the oil.
pH Up and pH Down
Maintaining the proper pH level of your cannabis garden, whether soil grown or hydroponically, is vital to deterring the growth of disease bearing fungi. Highly acidic environments lend themselves to the fungi species that can be detrimental to your growing efforts.
pH Up and pH Down is used in hydroponic situations to adjust the alkaline and acidity levels. Tap water typically is at the 8.0 level due to the high alkaline content. The optimum pH level for hydroponically grown plants is 5.5 – 6.5. Acids are used to lower the pH level, while alkalis are used to raise the level. Be sure to use a product labeled for hydroponic use or you can damage the crop.
Potassium bicarbonate is a water soluble compound often used to neutralize acidic soil in crops. It is now under consideration as an organic fungicide. Potassium bicarbonate is a synthetic compound resultant of a combination of potassium carbonate, carbon dioxide and water and is found naturally in virtually all life forms. It is most seen in crystal form or as a soft, powdery substance.
Potassium bicarbonate is an effective defense against powdery mildew, Septoria leaf spot, blight and many other fungal diseases. To apply, mix three tablespoons potassium bicarbonate, three tablespoons oil and one half teaspoon castile soap with one gallon water. Pour mixture into a spray bottle and mist the cannabis leaves. (This also works on most edible plants).
Potassium bicarbonate can be purchased from garden centers, hardware stores and pharmacies, or can be obtained online under various brand names.
Pseudomonas is a genus of bacteria found in water and plant seeds. The application of this strain became widely used in the 1980′s as a way to prevent the growth of crop pathogens. It is applied to the soil or seeds, in agriculture. It is believed the introduction of pseudomonas to the soil or seeds, induces systemic resistance of the emerging plant to pathogens. The application is available by several manufacturers to control many fungal and bacterial diseases. Pseudomonas refers to a variety of species, so check labels for the particular fix you need.
This is a broad term referring to a class of compounds which act as disinfectants. Its use should be confined to cleaning gardening tools and work surfaces, but should not be applied to consumable plants. Sterilizing equipment and surfaces with quaternary amines will help guard against the spread of fungal pathogens to your cannabis or other plants. Check the internet for suppliers.
Silica and Silicate Salts
When silica is added to the soil, it provides a strengthening agent for plant cells; it facilitates thicker cell walls, which results in stronger stems. The availability of silica to a plant’s roots provides a protective barrier, dissuading fungal reach into the inner workings of the plant’s ability to uptake nutrients. The plant becomes more capable of surviving stress once clad with the armor silica provides. In addition, enhancing the soil with silica containing materials help to keep it aerated, allowing free flow of oxygen. This is good news for Mary Jane and her counterparts!
Hydroponic environments can also benefit from the addition of soluble silicon added to the water solution. The roots become stronger and healthier, resulting in increased yields. The addition of silica in either growing situation has proven to reduce the occurrence of powdery mildew.
Several forms of silica are available for soil or water growing media:
• Syna-Gro Po-Tekt, a potassium silicate solution, can be used in the soil, hydroponic systems and as a foliar spray. • Pyrophyllite clay, and aluminum silicate in powder form, can be applied as a dust or foliar spray. • Silica stone is used in hydroponic systems and can be re-used after a thorough cleaning. • Greensand can be added to the soil to enhance the benefits of silica. • Vermiculite and perlite is available at garden centers. Mix it into the soil. Many potting soils come with the amendments already added. • Diatomaceous earth contains the shells of marine microorganisms. This amendment also serves as a control for soft organisms such as slugs, as the tiny shells pierce their skin causing dehydration through the loss of body fluids.
Colloidal silver has long been used as a defense against algae in swimming pools and hydroponic systems. It serves to guard against plant attacking pathogens such as bacteria, viruses and fungi. Pathogens are literally suffocated to death by the tiny metal ions attaching to their respiratory systems. It is a completely safe control, as humans, plants and animals will not be harmed. It can be used in the germination process, as a soil soak or foliar application. In fact, colloidal silver has been known to strengthen many food bearing plants, including their immune systems. Marijuana plants will not be harmed in the least, as there is no such thing as overdose with colloidal silver.
Commonly know as good old baking soda, this inexpensive medium has many uses, including homemade treatments for ailing gardens. By utilizing baking soda in the garden, the cannabis farmer can prevent and/or control many fungal diseases. Baking soda also has the benefit of adding to the good health of your crop.
Powdery mildew will stunt the growth of your plants and eventually lead to their demise if not caught and corrected. To make a foliar spray, combine one teaspoon baking soda with four cups water and one half teaspoon liquid dish detergent or, preferably, castile soap. Spray the affected plants once every two weeks until the infection has dissipated. You don’t want to overwater due to the higher sodium levels than are in potassium bicarbonate.
Streptomyces Griseoviridis – Beneficial Bacteria
That’s a mouthful, huh? This particular bacterium is available commercially and is used to prevent root rot, stem rot, wilt and various fungal diseases such as Fusarium, gray mold and Pythium. Mycostop, RootGuard and Microgrow are a few products available to the cannabis gardener.
Fungi cannot make their own food therefore they depend on your beloved Mary Jane (and other foliage) for food. Consider them the vampires of the plant world. When they appear there should be one goal in mind: attack and retreat!
Sulfur can lower the pH level of highly alkaline soils and is also used as a treatment for powdery mildew, gray mold and Septoria. If using as a foliar spray, test it on a few branches and wait a couple of days before applying, as sulfur can cause leaf damage if not applied properly. Sprinkle sulfur dust on the infected plants, but follow directions carefully. Sulfur can be applied as a dust or foliar spray. Sulfur in both liquid and powder form is available at most garden centers.
Trichoderma – Beneficial Fungi
Trichoderma is present in all soils and has been developed as a bio control against fungal diseases due to its opportunistic lifestyle. It is parasitic in nature, forming on the roots and feeding on other fungi. Trichoderma has also been known to deter foliar fungal diseases. Recent studies have shown that due to the parasitic nature, Trichoderma actually promotes healthy root growth. Check the internet for approved available commercial products.
UVC lights are non-chemical fungal controls for the hydroponic or indoor growing system. They can be placed in the air ventilation system to help eliminate algae, mold and mildew spores from penetrating the indoor garden. It is important to mention that if you have added beneficial microbes to your hydroponic cannabis system, they will also be eradicated, so you may want to think twice when considering this form of control. UVC lights can be purchased at hydroponic supply houses and online.
In the growing trend towards green living and green gardening, many household items have once again come to light with available uses other than the apparent. As a fungicide, add one tablespoon white distilled vinegar and one quart water to a spray bottle. Spray your plants to kill powdery mildew. Make sure you use a diluted vinegar solution. Vinegar alone is a great weed killer, but is non-selective. Vinegar in its full strength will kill all vegetation it hits.
Want to know more about growing marijuana? Check out the FREE book Marijuana Plant Care for more information!