Iittii H i It ilitll

Lightly cultivate the soil surface, so water penetrates evenly. Be careful not to disturb roots.

A 1 to 2-inch (3-5 cm) layer of hydro clay mulch on soil surface keeps soil surface moist. Roots are able to grow along the surface, and the soil does not need to be cultivated. The Roots turn green and grow poorly when they receive mulch also decreases evaporation and helps direct light.

keep irrigation water from damaging roots or |jght does ^ penetrate and s|ow foot ^^

sp s' If roots around the outside of the root ball start

R t turning green, you know they are receiving direct light. Remedy the problem by painting White containers reflect light and keep soil the inside of the container with a non-toxic latex cooler. Always use thrck, white containers so

These outdoor plants are thriving in Canada.



Botrytis Cannabis

This beautiful greenhouse crop was dlstroyed by botrytis.

Dirty grow rooms help cause pest and disease problems.

Sweep the grow room floor every few days to avoid problems with pests and diseases.

Simple hygiene in the grow room keeps pests and diseases in check.

Dirty grow rooms help cause pest and disease problems.

Sweep the grow room floor every few days to avoid problems with pests and diseases.


Insects, mites, and maggots slither into grow rooms eating, reproducing, and wasting weed. Outdoors, they live everywhere they can. Indoors, they live anywhere you let them. Fungi are present in the air at all times. They may be introduced by an infected plant or from air containing fungus spores. Fungi will settle down and grow if climatic conditions are right. Pests, fungi, and diseases can be prevented, but if allowed to grow unchecked, extreme control measures are often necessary to eradicate them.


Cleanliness is the key to insect and fungus prevention, The grow room should be totally enclosed so (he environment can be controlled easily. Keep the floor clean. Keep all debris off soil surface. Do not use mulch. Insects and fungi like nice hideaway homes found in dirty, dank corners, and under dead decaying leaves or rotting mulch, Growers and their tools often transport many microscopic pests, diseases, and fungi that could ultimately destroy the garden. This docs not mean growers and their tools have to be hospital clean every time lliey enter a grow room, even though that would be nice, it does mean normal and regular sanitary precautions must he taken. Growers who wear clean clothes and use clean tools reduce problems considerably. A separate set of indoor tools is easy to keep clean. Pests, diseases, and fungi habitually ride from plant to plant on dirty tools. Disinfect tools by dipping in rubbing alcohol or washing with soap and hot water after using them on each diseased plant. Another quick way to sterilize pruners is with a hand-held torch. A quick heating with the torch will sterilize metal tools immediately.

Personal cleanliness is fundamental to preventing pests and diseases. Wash your hands belore touching foliage and after handling diseased plants. Smart growers do not walk around the buggy outdoor garden and then visit the indoor garden. They do it vice versa. Think before entering the indoor garden and possibly contaminating it. Did you walk across a lawn covered with rust fungi or pet the dog that just came in from the garden outside? Did you just fondle your spider mite-infested split-leaf philodendron in the living room? Avoid such problems by washing your hands, and changing shirt, pants, and shoes belore enteritis an indoor garden.

Once a crop has been grown in potting soil or soilless mix, throw out the grow medium. Some growers brag about using the same old potting soil over and over, unaware that this savings is repaid with a diminished harvest. Used soil may harbor harmful pests and diseases that have developed immunity to sprays. Starting a new crop in new potting soil will cost more up front but will eliminate many potential problems. Used soil makes excellent outdoor garden soil.

Be careful when discarding used soil! Growers in Eugene, Oregon, tossed their outdoor soil out in the backyard for many years. The soil was about 50 percent white perlite and had a distinctive color. This oversigiit eventually led to the growers' arrest.

Once potting soil is used, it loses much of the fluff in the texture, and compaction becomes a problem. Roots penetrate compacted soil slowly, and there is little room for oxygen, which restricts nutrient uptake. Used potting soil is depleted of nutrients. A plant with a slow start is a perfect target (or disease, and worst of all, it will yield less!

Companion planting helps discourage insects outdoors. Posts have nowhere to go indoors, so companion planting is not viable in the grow rooms.

Plant insect- and fungus-resistant strains of marijuana. If buying seeds Irom one of the many seed companies, always check for disease resistance. in general, Cannabis indica is the most resistant to pests, and sativa is more resistant to fungal attacks. Choose mother plants that you know are resistant to pests and diseases.

Keep plants healthy and growing fast at all times. Disease attacks sick plants first, Strong plants tend to grow faster than pests and diseases can spread.

Forced air circulation makes life miserable for pests and diseases. Pests hate wind because holding on to plants is difficult, and flight paths are haphazard. Fungal spores have little time to settle in a breeze and grow poorly 011 wind-dried soil, steins, and leaves.

Ventilation changes the humidity of a room quickly. In fact, a vent fan attached to a humidis-tat is often the most effective form of humidity control. Mold was a big problem in one of the grow rooms that I visited. The room did not have a vent Ian. Upon entering the enclosed room, the

Anthracnose Fungus Marijuana Plants

Healthy plants are easy to keep strong and are able to fight off pests and diseases.

Healthy plants are easy to keep strong and are able to fight off pests and diseases.

humid air was overpowering. It was terrible! The environment was so humid that roots grew from plant stems. The grower installed a vent fan to suck out moist, stale air. The humidity dropped from nearly 100 percent to around 50 percent. The mold problem disappeared, and harvest volume increased.

Indoor horticulturists who practice all the preventative measures have fewer problems with pests and diseases. It is much easier to prevent the start of a disease than it is to wipe out an infestation. If pests and diseases are left unchecked, they can devastate the garden in a few short weeks.


Sometimes, even when all preventative measures are taken, pests and diseases still slink in and set up housekeeping. First, they establish a base on a weak, susceptible plant. Once set up, they launch an all-out assault on the rest of the garden. They move out in all directions from the infested base, taking over more and more space, until they have conquered the entire garden. An infestation can happen in a matter of days. Most insects lay thousands of eggs in short periods of time. These eggs hatch and grow into mature adults within a few weeks. For example, if 100 microscopic munchers each laid 1000 eggs during their two weeks of life and these eggs grew into adults, two weeks later 100,000 young adults would lay 100 eggs each. By the end of the month, there would be 100,000,000 pests attack-

Manually remove small populations of pests by smashing pests and eggs between your fingers. Make sure to wash your hands afterward,

Logical Progression of Insect Control

1. Prevention

2. Manual Removal



a, fingers


Use new soil

b. sponge


One indoor

set of tools



3. Organic Sprays



Healthy plants


Climate control

4. Natural Predators


No animals



5. Chemicals


Manually remove small populations of pests by smashing pests and eggs between your fingers. Make sure to wash your hands afterward, ing the infested garden. Imagine how many there would be in another two weeks!

Sprays often kill adults only. In general, sprays should be applied soon after eggs hatch so young adults are caught in Iheir weakest stage of life. Very lightweight (low viscosity) horticultural oil spray works well alone or as an additive to help kill larvae and eggs.

The availability of some sprays can be seasonal, especially in more rural areas. Garden sections of stores are changed for the winter, but extra stock is sometimes kept in a storage room. Look for bargains on sprays at season-end sales. Today, there are many indoor grow stores that carry pest and disease controls all year round.

Insect Control

Indoor gardeners have many options to control insects and fungi. Prevention and cleanliness are ai the top of the control list. A logical progression to pest and disease control is outlined in the chart on this page. (Note that it begins with cleanliness!)

Manual removal is just what the name implies -smashing all pests and their eggs in sight between the thumb and forefinger or between two sponges.

I like natural-organic sprays such as pyrethrum and neem and use harsh chemicals only as a last resort. Any spray, no matter how benign, always seems to slow plant growth a little. Slomata become clogged when foliage is sprayed and covered with a filmy residue. Stomata stay

Yellow sticky traps are used to monitor pest populations as well as to control small flying insects.

A 30X battery-powered magnifying scope makes insects and diseases easier to identify.



Common chemicals with their trade names and the insects they control:

Note: Do not apply these substances to edible plants

Generic Name


Enter System












semi synthetic (Terra my on®)


foliar fertilizers




not truly systemic, actually translaminar













Vi ta va x






NOTE: This list is not all-inclusive. The basic rule is to not use systemic products.

NOTE: This list is not all-inclusive. The basic rule is to not use systemic products.

plugged up until the spray wears off or is washed off, Stronger sprays are often more phytotoxic, burning loliage. Spray plants as little as possible and avoid spraying for two weeks before harvest. Read all labels thoroughly before use.

Use only contact sprays that are approved for edible plants. Avoid spraying seedlings and tender unrooted cuttings. Wait until cuttings are rooted and seedlings are at least a month old before spraying.

Sprays and Traps

Chemical fungicides, insecticides, and miticides

I do not recommend using chemical fungicides, fungistats, Insecticides, or milicides on plants that are destined for human consumption. Most contact sprays that do not enter the plant system are approved for edible fruits and vegetables. However, there are numerous ways to control fungi, diseases, and pests without resorting to

EPA pesticide acute toxicity classification:

Class LD50 to kill Rat Oral (mg kg-1 )

LD50 to kill Rat Dermal (mg kg-l)

LD50 to kill Rat Inhaled (mg kg-1)

Eye Effects

Skin Effects

1 50 or less

200 or less

0.2 or less

corrosive opacity not reversible


1! 50-500



corneal opacity reversible within 7 days, irritation persists for 7 days

severe irritation at 7?. hours

111 500-5000



no corneal opacity, irritation reversible within 7 days

moderate irritation at 72 hours

IV > 5000



no irritation

mild irritation


Remedy Chart








Active ingredient

EPA Class

Bacillus species

G, D, WP

Bt, DiPel, M-Trak,


Mattch, Javelin, etc.

Copper sulfate




Copper sulfate/lime


Bordeaux mixture


Diatomacious earth




No em

0, EL

Neem, Bioneem


Nicotine sulfate

L, D

Black Leaf 40


Oil, dormant horticultural





A, L, WP

Many trade names








Derris, Cubé

II, 111



Dyan 50




Red Devil


Soap, insectlcidal


M-Pede, Safer's


Sodium bicarbonate


Baking soda


Sodium hypochlorite









L - Liquid

A - Aerosol

WP - Wettable Powder

D - Dust


EL - Emulsifiable Liquid

G - Glandular

chemicals. On the previous page is a chart of common chemicals with their trade names and the insects they control.

Spreader-Sticker for Pesticides

Spreader-stickers improve and promote wetting and increase sticking and absorption through foliage. Spreader-sticker products increase effectiveness of fertilizers, fungicides, insecticides, etc They are especially important to use when plants develop a waxy coating of resin. Spreader-stickers also impair insects' respiration mechanisms and function as pesticides, One of my favorite spreader-stickers is Coco-Wet from Spray-N-Crow.


Ingredients: Abamectin derivatives include emamectin and milbemectin. Does not bioaccu-mulate. Used extensively on hops; abamectin is not truly systemic. It is absorbed from the exterior of foliage to other leaf parts, especially young leaves, in the process of translaminar activity.

Controls: Russet and spider mites, fire ants, leafminers, and nematodes.

Mixing: Dilute in water. Mix 0.25 teaspoon (0.125 cl) per gallon {3.8 L). Use a wetting agent. Application: Spray. Works best when temperature is above 70°F (2l°C). Repeat applications every seven to ten days. Persistence: One day. Forms: Liquid.

Toxicity: Toxic to mammals, fish, and honeybees in high concentrations. Sucking insects are subject to control while benefices are not hurt. Safety: Wear gloves, mask, and safety glasses.

Bacillus thuringiensis (Bt) and other

Bacillus species

Ingredients: Bacillus thuringiensis (Bt) is the best known of several bacteria that are fatal to caterpillars, larvae, and maggots.

Caterpillars, larvae, and maggots all eat Bt bacteria, which can be applied as a spray, dust, or granules. Inject liquid Bt into stalks to kill borers. Shortly alter they ingest it, their appetite is ruined, and they stop eating. Within a few days they shrivel up and die; cabbage loopers, cabbage-

worms, corn earworms, cutworms, gypsy motli larvae, and hornworms are controlled. Commercial Bt products do not reproduce within insect bodies, so several applications may be necessary to control an infestation. Microbial Bt bacteria are nontoxic to animals (humans), beneficial insects, and plants; however, some people do develop an allergic reaction. Commercial Bt products do not contain living Bt bacteria, but the Bt toxin is extremely perishable. Keep within prescribed temperature range, and apply according to the directions. Most effective on young caterpillars, larvae, and maggots, so apply as soon as they are spotted.

Get the most out o( Bt applications by adding a UV inhibitor, spreader-sticker, and a feeding stimulant such as Entice1«», Konsume or Pheast<u>. Bt is completely broken down by UV light in one to three days.

B. thuringiensis var. kurstaki (Btk)-introduced on the market in the early 1960s-is the most popular Bt. Toxic to many moth and caterpillar larvae including most of the species that feed on flowers and vegetables. Sold under many trade names DiPeh", BioBifn, Javelin^, etc,, Btk is also available in a microencapsulated form, M-Trakw, Mattchm; etc. The encapsulation extends the elfective life on foliage lo more than a week.

B. thuringiensis var, aizawai (Btci) is effective against hard-to-kill budworms, borers, army-worms and pests that have built up a resistance to Btk,

B. thuringiensis var. israelensis (dt-i) is effective against the larvae of mosquitoes, black flies, and fungus gnats. Look for Gnatrol it), Vectobac i<, and BacrimoS'i*1. All are lethal to larvae. Adults do not feed on plants and are not affected. Fungus gnats can cause root problems Including rot. Use Bti to get rid of them as soon as they are identified.

B. thuringiensis var. morrisoni Is a new strain of Bt under development for insect larvae with ¿1 high pH in their guts.

B. thuringiensis var. san diego (Btsd) targets the larvae of Colorado potato beetles and elm beetle adults and other leal beetles.

B. thuringiensis var. tenebrionis (Btt) is lethal to Colorado potato beetle larvae.

B. cereus helps control damping-off and root-knot lungus. It flourishes in water-saturated mediums and promotes beneficial fungus that attacks the diseases.

B. subtilis is a soil-dwelling bacterium that curbs

Fusarium, Pythium, and Rhizoctonia that cause damping-off. It is commercially available under the brand names Epic®, Kodiacw, RhizO-Plus'H', Serenade h, etc. Soak seeds and apply as a soil-drench.

B. popilliae colonize larvae and ^rub bodies that consume it, causing them to turn milky-white before dying. It is often called milky spore disease. It is most effective against Japanese beetle grubs.

U.ikiiuj Sod, 1

Ingredients: Sodium bicarbonate.

Controls: Powdery mildew.

Caution: Baking soda kills fungus by changing the pH of foliage surface. It functions as a lungis-tat, not as a fungicide, that eradicates the organisms.

Mixing: Saturate in water.

Application: Spray or dust foliage.

Persistence: One to three days.

Forms: Powder.

Toxicity: None to mammals, fish, beneficlals.

Safety: Wear a mask to avoid inhaling dust.

Bleach, laundry

Ingredients: Sodium hypochlorite.

Controls: Numerous bacteria and fungi.

Caution: Avoid skin contact and inhalation. Concentrate burns skin and stains clothes.

Mixing: Dilute 5 or 10 percent solution with water.

Application: llse as a disinfectant on containers, walls, tools, etc.

Persistence: Evaporates with little residual in a couple of days.

Forms: Liquid.

Toxicity: Toxic to fish, beneficiáis, and humans if swallowed or gets in eyes.

Safety: Wear a mask and gloves when handling concentrate. Avoid skin contact and respiration.

Bordeaux mixture

Ingredients: Water, sulfur, copper (copper sul-


fate) and lime (calcium hydroxide).

Controls: Most often used as a foliar fungicide. Also, controls bacteria and fends off other insects.

Caution: Phytotoxic when applied to lender seedlings or foliage in cool and humid conditions.

Mixing: Apply immediately after preparing.

Application: Agitate the mixture often while spraying so ingredients do not settle out.

Persistence: Until it is washed from loliage.

Forms: Powder and liquid.

A Toxicity: Mot toxic to humans and animals, but somewhat toxic to honeybees and very toxic to fish.

Safety: Wear a mask, gloves, and long sleeves.

Boric acid

Ingredients: Available in the form of borax hand soap and dust.

Controls: Lethal as a contact or stomach poison. Kills earwigs, roaches, crickets, and ants.

Caution: Phytotoxic when applied to foliage.

Mixing: Mix borax soap in equal parts with powdered sugar to make toxic bait.

Application: Set bait out on soil near base oi plants,

Persistence: Avoid getting bait wet as it disperses rapidly.

Forms: Powder.

Toxicity: Mot toxic to honeybees and birds.

Safety: Avoid breathing dust.

Bug Bombs

Ingredients: Often bug bombs are packed with very strong insecticides and milicides, including synthetic pyrethrins that exterminate every pest in the room. They were developed to kill fleas, roaches, and their eggs that hide in furniture and in carpets.

Controls: According to most bug bomb labels, they kill everything in the room!

Caution: Use only as a last resort and follow the label's instructions to the letter,

Mixing: None.

Application: Place the bug bomb in the empty room. Turn it on and then leave the room.

Persistence: Low residual. Persistence is limited to a day or two,

Forms: Aerosol.

Toxicity: Read label for details.

Safety: Wear a mask, gloves, and cover exposed skin and hair.


Ingredients: The compounds-copper sulfate, copper oxychloride, cupric hydroxide and cuprous oxide -are common forms of fixed copper used as a fungicide and are less phytotoxic than unfixed (pure) copper.

Controls: Gray mold, foliar fungus, anthracnose, blights, mildews, and a number of bacterial diseases,

Caution: Easy to overapply and burn foliage or create a copper excess in plant.

Mixing: Apply immediately after preparing.

Application: Agitate the mixture olten while spraying, so ingredients do not settle out, Preferred temperature range lor application is 65-65°F (18-29"C).

Persistence: Lasts two weeks or longer indoors, if not washed off.

Forms: Powder and liquid.

Toxicity: Toxic to fish. Not toxic to birds, bees, mammals.

Safety: Wear a mask and gloves, cover exposed skin and hair.

Diatomaceous Earth (DE)

Ingredients: Naturally occurring DE includes fossilized-silica-shell, remains ol the tiny one-celled or colonial ft creatures called diatoms. It also *

contains 14 trace minerals in a chelated (available) form.

Controls: Although not registered as a pesticide or fungicide, DE abrades the waxy coating on pest shells and skin, including aphids and slugs, causing body fluids to leak out. Once ingested, the razor-sharp particles in DE rip tiny holes in the pest's guts, causing death.

Caution: Do not use swimming pool diatomaceous earth.

Homemade sprays can be made by blending water, lemon, vegetable oil, and garlic.

Chemically treated and heated, it contains crystalline silica that is very hazardous if inhaled. The body is unable to dissolve the crystalline form of silica that causes chronic irritation.

Mixing: No mixing required when used as a dust. Mixing required when used as spray. Apply as a powder or encircle slug-damaged plants and use as a barrier.

Application: Apply this spray to infestations caused by pest insects.

Persistence: Stays on foliage for a few days or until washed off.

Forms: Powder.

Toxicity: Earthworms, animals, luimans, and birds can digest diatomaceous earth with no ill-effects. Avoid contact with skin and eyes.

Safety: Wear a protective mask and goggles when handling this fine powder to guard against respiratory and eye Irritations.

Homemade Pest and Disease Sprays

Ingredients: A strong, hot taste, smelly odor, and a desiccating powder or liquid are the main ingredients in home-brewed pesticide and fungicide potions. See below.

Controls: Homemade sprays discourage and control pests including aphids, thrips, spider mites, scale, and many others.

Caution: Be carelul when testing a new spray. Apply it to a single plant and wait for a few days to learn the outcome before applying to all plants.

Mixing: Make spray concentrates by mixing repellent substances with a little water in a blender. Strain the resulting slurry concentrate through a nylon stocking or fine cheesecloth before being diluted with water for application.

Application: Spray foliage until it drips from both sides of leaves.

Persistence: A few days.

Forms: Liquid.

Toxicity: Usually not toxic to humans in dosages lethal to pests.

Safety: Wear a mask and gloves, and cover skin and hair. Avoid contact with eyes, nose, lips, and ears. Neem tngredients: Relatively new in the USA, neem has been used for medicine and pest control for more than four centuries in India and Southeast Asia. Extracted from the Indian neem tree, A/adirachla indica, or the chitiaberry tree, Melici azedarach, neem is an antifeedant and disrupts

Homemade sprays can be made by blending water, lemon, vegetable oil, and garlic.

insect lile cycles. The trees are known as the village pharmacy because they supply cures lor humans and animals as well as safely control countless pests and lungi. Neem powder is made Irom leaves. The active ingredient, azadirachtin, confuses growth hormones and pests never mature into adults to produce more young. It is most effective against young insects and is available in various concentrations. It also contains N-P-li and trace elements.

Controls: Most effective against caterpillars and other immature insects including larvae of white-flies, fungus gnats, mealybugs, and leafminers.

Caution: Neem is not as effective agiiinst spider mites as neem oil.

Mixing: Often mixed with vegetable (canola) oil. Mix just before using in water with a pH below 7 and use a spreader-sticker. Agitate constantly while using to keep emulsified, throw out excess.

Application: Use as a soil-drench or add to the nutrient solution. This allows neem to enter into the plant's tissue and become systemic. Used as

Continue reading here: Recipes and Controls Chart

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