Plant Disease
Spraying Basics
1. It is best to use any type of spray in the early morning or the cool of evening. Do not spray when temps are above 80 degrees Fahrenheit! Your plants may "burn" or have a reaction to what you are using in excessive heat. This is known as "phytotoxicity."
2. Always perform a test on a small portion of the plant material first. Wait 24 hours to observe any negative reaction. Proceed if there is no damage.
3. Really and truly...more is not better. If you are not getting good results don't increase the strength of these remedies without testing first.
4. Target just the area you need to treat. Be careful... try not to harm the good bugs! You don't want to run off your allies.
5. When working with sprays or dusts always protect your exposed skin and face. Some of these ingredients can be very irritating to your skin, eyes and mucous membranes, especially any hot pepper sprays.
Specific Disease Controls
Apple tree scab: Grow any member of the onion family around the base of the tree. Chives work the best. You can also make a tea from chives and use as a spray on your apple trees to help protect from scab.
Brassicas: Keeping the soil pH around 7.0 to prevent club root disease.
Peach tree leaf curl: This is a common disease of peach trees. Sprays of horsetail tea, garlic (look further down the page for recipes) and seaweed can help to prevent this problem. Growing chives underneath them also helps.
Neem Oil will help prevent rust disease, black spot and can act as a general fungicide.
Potato scab: When planting your potato sets put some wilted comfrey leaves in with them to prevent scab. Also keeping the soil for your potato patch with a pH of 5 or below (acid) or a pH of 7 or above (alkaline) to prevent scab.
General Disease Controls
Apple Cider Vinegar Fungicide
For leafspot, mildew, and scab
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Mix 3 tablespoons of cider vinegar (5% acidity) with one gallon water and spray in the morning on infested plants. Good for black spot on roses and aspen trees too.
Baking Soda Spray
For anthracnose, early tomato blight, leaf blight and spots, powdery mildew, and as a general fungicide
Sodium bicarbonate commonly known as baking soda has been found to posses fungicidal properties. It is recommended for plants that already have powdery mildew to hose down all the infected leaves prior to treatment. This helps to dislodge as many of the spores as possibly to help you get better results. Use as a prevention or as treatment at first signs of any of the diseases.
To make: Mix 1 tablespoon baking soda, 2 1/2 tablespoons vegetable oil with one gallon of water. Shake this up very thoroughly. To this mix add 1/2 teaspoon of pure Castile soap and spray. Be sure to agitate your sprayer while you work to keep the ingredients from separating. Cover upper and lower leaf surfaces and spray some on the soil. Repeat every 5-7 days as needed.
Chive Spray:
For preventing apple scab and downy mildew on cucumber, pumpkin and zucchini.
To make: Put a bunch of chopped chives in a heat proof glass container, cover with boiling water. Let this sit until cool, strain and spray as often as two to three times a week.
Compost and Manure Teas
Many people have success with manure tea keeping blight and other pathogens away from plant. Soak the area around plants and use as a foliar spray. Do not use on seedlings as it may encourage damping-off disease.
Fill a 30 gallon trash can with water. Let sit for 24 hours to evaporate the additives (use rain water if you can). Add about 4 shovels worth of manure to this and cover. Let it sit for 2-3 weeks, stirring once a day. Strain and apply as needed.
Various manures supply nutrients as follows:
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Chicken manure: nitrogen rich: use for heavy feeders such as corn, tomatoes and squash.
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Cow Manure: potash: use for root crops.
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Rabbit manure: promotes strong leaves and stems.
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Horse manure: leaf development.
Compost Tea: Make and use just the same as you would the manure tea. This is another terrific reason to compost all those prunings, grass clipping and kitchen wastes. Or you can use our HumAcid for a ready made foliar spray with all the goodness of compost!
Corn and Garlic Spray Fungus Preventative
This blend is surprisingly potent preventative spray to protect your plants.
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To make: Gather a handful of corn leaves, clematis leaves (any kind) and as much of the papery outer leaves of garlic as you can. Process thoroughly in a blender. The mix with sufficient water to make a thin liquid. Let sit for an hour, strain and spray on plants as a preventative.
To make: Put a handful of fresh rhizomes in a glass pot. Pour 1 quart of boiling water over rhizomes, cover and let steep for 10 minutes. Strain, let cool and use right away.
Elder Leaf Spray:
Elder leaves have fungicidal properties and may be useful against mildew and black spot diseases.
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To make: simmer 8 ounces of leaves in 16 ounces of water for 30 minutes. Stir this thoroughly, then strain. Take 16 ounces of warm water and mix with 1 tablespoon of Castile soap. Add soap mixture to the elder water, spray as needed. Note: Set your sprayer to a coarse or large droplet setting as this mixture will tend to plug a fine setting.
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To make: Combine 3 ounces of minced garlic cloves with 1 ounce of mineral oil. Let soak for 24 hours or longer. Strain.
Next mix 1 teaspoon of fish emulsion with 16 ounces of water. Add 1 tablespoon of castile soap to this.
Now slowly combine the fish emulsion water with the garlic oil. Kept in a sealed glass container this mixture will stay viable for several months. To use: Mix 2 tablespoons of garlic oil with 1 pint of water and spray.
Try our Garlic Barrier Insect Repellent
Horseradish
(preventative for fungal disease)
Penn State University announced in 1995 that minced horseradish holds promise in decontaminating wastewater and now says it may clean contaminated soils as well!
Penn State's center for Bioremediation and Detoxification reports that minced horseradish combined with hydrogen peroxide can completely remove chlorinated phenols and other contaminants found in industrial wastes. Experiments involve applying the mixture directly to tainted soils or growing horseradish in contaminated soil and roto
The cleansing properties of horseradish have been known for more than a decade, however creating a purified form has been far too expensive. This method has proved to be just as effective, but at a fraction of the cost!
Horseradish Tea: You can also make a tea from horseradish roots to use as a preventative spray for fungal diseases. This is especially useful against brown rot in apple trees. The white flesh of the horseradish root also contains significant amounts of calcium, magnesium and vitamin C.
To make: Process one cup of roots in food processor till finely chopped. Combine this with 16 ounces of water in a glass container and let soak for 24 hours. Strain liquid, discard the solids. Now mix the liquid with 2 quarts of water and spray.
Hydrogen Peroxide Treatment
To prevent bacterial and fungal problems on outdoor plants use hydrogen peroxide! Hydrogen peroxide will prevent the disease spores from adhering to the plant tissue. It causes no harm to plants or soil, however don't use on young transplants or direct seeded crops until they have become established. Warning: Always test on a small portion of plant tissue first to check for any negative reactions. Do not proceed if there is any damage to plant tissue. Do not substitute food grade H2O2 for the common H2O2. Spray plants with undiluted 3 percent hydrogen peroxide that you can buy most anywhere. Be sure to cover tops and bottoms of leaves. Do this once a week during dry weather and twice a week in wet weather. This works as a preventative. If you already have problems use this as a direct treatment.
Milk with its' natural enzymes and simple sugar structures can be used to combat various mildews on cucumber, asters, tomato, squash and zinnia foliage. This works by changing the pH on the surface of the leaves, so they are less susceptible to mildew. Use a 50/50 mixture of milk and water. Thoroughly spray plants every 3 to 4 days at first sign of mildews or use weekly as a preventative measure.
Milk can also be mixed at a rate of 2 ounces milk to 18 ounces of water and used as a spray every 7 to 10 days to treat mosaic disease on cucumber, tomato and lettuce.
Tomato Virus Protective Spray
To prevent the many viruses that attack tomato plants this simple remedy really works! The antitranspirant protects the plant surface against disease spores. The skim milk provides the tomato plant with calcium. A calcium deficiency is common in tomato plants.
Antitranspirants can be used to protect many plants against bacterial disease before they attack. They are harmless and will not block the pores of the plant tissue.
To make: Mix 1/2 teaspoon of antitranspirant (like Cloudcover, Wiltpruf etc.) with 8 ounces of skim milk, and 1 gallon of water. Spray plants. Clean out your sprayer when done and flush with fresh water..
NOTE: an equivalent of prepared powdered milk may be substituted for the skim milk.
Removing leaves on the lower portion of the plant may help lessen contact with disease spores and certainly won't hurt the plant.
Seedlings: Damping off disease
Always use a sterile growing medium like mixes with vermiculite and perlite for your seed starting as these should not contain the fungi that cause damping-off. Water your seedlings with warm water that has been left to sit for an hour or more to dissipate most of the chemicals that are present in tap water. Using cold water stresses the seedlings leaving them vulnerable to harmful organisms.
1. Chamomile Spray: Chamomile tea is an excellent preventative for damping-off. Use on seed starting soil, seedlings and in any humid planting area. Chamomile is a concentrated source of calcium, potash and sulfur. The sulfur is a fungus fighter. This can also be used as a seed soak prior to planting.
To make: Pour 2 cups boiling water over 1/4 cup chamomile blossoms. Let steep until cool and strain into a spray bottle. Use as needed. This keeps for about a week before going rancid. Spray to prevent damping off and anytime you see any fuzzy white growth on the soil. Chamomile blossoms can be purchased at health food stores and usually grocery stores.
2. Seaweed Spray: A seaweed spray which is so rich in nutrients and everything that seedlings require can also be used to prevent damp-off. Make a strong mixture adding 2/3 cup of kelp concentrate to 1 gallon of water, spray.
3. Horsetail Tea (Equisetum arvense)
The common horsetail plant, which is very invasive, is rich in silicon and helps plants to resist fungal diseases via increasing their light absorbing capabilities. Use on peach trees to control peach leaf curl. Use on most plants to combat powdery fungi, and on vegetables and roses to control mildew. Horsetail is one of the ingredients in Golden Harvest Fertilizer. (psssst...subliminal message)
You can use this on seedlings and plants in closed environments too! Great in greenhouses! Prevents damping off.
To make:
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In a glass or stainless steel pot, mix 1/8 cup of dried leaves in 1 gallon of unchlorinated water. Bring to a boil, then let simmer for at least 1/2 hr. Cool and strain.
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Store extra concentrate in a glass container. Will keep for a month.
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Dilute this mix, adding 5-10 parts of unchlorinated water to one part concentrate. Spray plants that show any symptoms of fungal type disease once every 4 days. Spray your seed starting mixtures to prevent damping off.
4. Spread finely milled sphagnum peat moss on the soil surface of your seed beds or flats.
5. Sprinkle powdered cinnamon on soil surface...yes this can work!
