If your plants are looking undernourished and they are infested with insect pests and powdery mildew fungus, I have a simple question for you: got milk?
In response to a previous column that mentioned non-toxic insecticides, I received an email from Robert Wayne Steele, Sr., who gardens in West Covina. Steele wrote as follows: “I am a very long time vegetable gardener and have found that whole milk, full strength in a spray bottle, will kill many of the ‘Big 5’ sucking insects (aphids, scales, mealybugs, whiteflies, thrips) that you mentioned in your article. I always seem to have a problem with colonies of those little suckers on the leafy greens, kale, broccoli, cabbage especially. After a few treatments they are greatly reduced and easy to control. It may require application every other day or so to be effective, but it does work. I heard about this method 50 years ago from a friend of my grandmother, who was also an avid gardener. It seems that these little monsters are lactose intolerant and the milk also plugs up their breathing tubes. The best thing is that it is inexpensive and does not negatively impact your vegetables or the plants, whose leaves grow to a massive size.”
Paula Aberasturi, who blogs and tweets from her farm in the Philippines as oysterhalfshell, offered this testimonial. “We’ve just recently discovered that milk is a fungicide! It’s as effective as standard chemical brands, or even more effective. How to do it? Get milk, mix with water (our solution is 1 part milk: 10 parts water) and spray twice a week. We use fresh, raw milk as we have milking cows in the farm. Based on our experience, raw milk works very well with all types of fungi and disease on our plants. It also works especially for powdery mildew. They say it is the phosphate in milk that boosts a plant’s immune system and fights the fungi. We have saved thousands this year by just spraying our crops with milk instead of using synthetic chemicals and fungicides. Who would have thought we would find the solution to our fungicide problems right in our backyard? Or in your fridge?”
A study by Dr. Wagner Bettiol, a research scientist in Brazil, demonstrated that milk was an effective deterrent to powdery mildew on zucchini. His findings were duplicated by melon growers in New Zealand who are saving thousands of dollars each year with a milk spray program for mildew control. In Australia, milk spray has been effective in controlling powdery mildew on grapevines and roses. Begonia powdery mildew, too, may be controlled with milk. Generally, a 10% milk solution is recommended (1 part milk: 9 parts water) with organic, raw, or skim milk preferable to 2% or whole milk, although Jeff Gillman, a professor of horticulture and botanical garden curator, claims that 1 part milk of any kind mixed with 2 parts water makes an excellent spray, applied once a week, for control of black spot on roses.
Spraying milk on a compost pile is also beneficial. Organic or raw milk is best since it has not been exposed to the heat and homogenization that destroys aerobic bacteria which assist in turning compost into sweet smelling humus. This might also explain why dousing plants with organic milk makes them healthier. Not only does it kill certain insects, especially aphids, on contact and prevent fungus, but the excess milk that drips onto the ground stimulates soil microbial activity that enhances plant health.
In Nebraska, a 10 year study spraying milk on grassy pasture land resulted not only in a significant increase in grass production, but greater soil porosity, too, a result of increased microbial activity in the soil due to its absorption of bacteria laden milk. In addition, sugar content in the pasture grass tripled and this was thought to explain the disappearance of grasshopper pests from the treated areas. Insects lack a pancreas, are unable to fully metabolize sugar, and thus stay away from sugar enriched plants.
For some time, I had noticed a distinctive clump of fasciated growth on a pride of Madeira (Echium candicans) in my garden. Fasciation occurs on a variety of plants and is characterized by a flattened, fan-shaped, contorted, or witches’ broom pattern of terminal growth. Thickened stems, undulating or wavy folds of growth (especially on cactuses), or a number of flower heads growing together may be observed. The causes of fasciation include genetic mutation, infection by a bacteria, fungus, or virus, insect activity, hormonal imbalance, and environmental or chemical stress.
Tip of the Week: Fasciation in certain plants, such as cockscomb celosia (Celosia argentea var. cristata), is inherited. These annuals are known for their red, pink, orange and yellow inflorescences in the shape of rooster headgear. Love-lies-bleeding (Amaranthus caudatus), a celosia relative, is a drought tolerant annual that self-sows with alacrity and may grow up to six feet tall. Amaranthus ‘Red Spike’ and ‘Red Garnet’ are burgundy-leafed cultivars. The leaves, stems, and even the young flowers of celosia and amaranthus are edible and may be tastily consumed as steamed vegetables.