At this time of year, it is common to see a whitish-gray powdery substance on the leaves of some plants. Powdery mildew can affect any plant, but lilacs, roses, fruit trees, vegetables, begonias, and lawns are particularly susceptible.
The term “powdery mildew” actually refers to an entire group of fungi, each one attacking different types of plants. Since the fungi are species specific, powdery mildew on your fruit trees won’t spread to camellias or other plants. It usually starts with a few round white or grayish spots that you can rub off with your finger. They spread and join until the entire top leaf surface is covered, then it moves on to the underneath, stems, flowers, and fruit.
As powdery mildew takes over, photosynthesis becomes very difficult for the plant. This can cause growth of the plant to slow and distort, leaves to fall, and flowers and fruits to fail to form properly.
Powdery mildew thrives in dry weather with high relative humidity. Unlike other fungi, it doesn’t like rain or extreme heat, and it tends to slow when temperatures soar over 90° F. Powdery mildew needs a dry leaf surface, moderate temperature, and high humidity to form. These conditions are often caused by:
Seasonal weather: A summer that combines drought with high humidity is an invitation to powdery mildew.
Crowded plants: Densely packed plants, overgrown shrubs, or plants under trees, are more susceptible to powdery mildew due to poor air circulation and cool, humid conditions.
Overfeeding: Lush, succulent growth caused by over fertilizing is particularly susceptible to powdery mildew.
Powdery mildew may seem to spring up faster than you can control it, but the good news is that it’s easy to treat and not immediately fatal. Take these steps to treat powdery mildew on your plants:
Natural treatments include neem oil, copper, and potassium bicarbonate.
A: Powdery mildew is white or gray powdery spots, often times covering most if not the entire leaf surface. It’s also found on plant stems, flowers and even fruit. Fortunately, the symptoms of powdery mildew are usually worse than the actual damage. The plant rarely dies.
If you find that some of your plants or trees have powdery mildew, don’t worry. This fungus is host specific, meaning just because you find it on one plant species, does not make it a threat to other type plants in your landscape. Although there are many different species of powdery mildew, the symptoms all look about the same from one to another.
Advanced stages can cause plant foliage to yellow, curl or turn brown and eventually cause the plant to defoliate prematurely. On flowering plants and trees, the fungus can lead to early bud drop or reduce the flower quality.
Conditions that favor mildew formation include dry foliage, high humidity, low light and moderate temperatures.
To help prevent powdery mildew, avoid over fertilization. New growth is more susceptible. Instead, apply a slow-release fertilizer that provides more controlled growth.
If you already have powdery mildew, early detection provides the best way to contain and potentially eliminate the problem. There are many commercial products that are effective at containing the spread.
DACONIL is a readily available fungicide that will help with the problem – be sure to follow label instructions exactly.
You may prefer the non-chemical route, and will want to try:
Neem oil: This is a readily available organic option to disease and pest control. Neem oil is extracted from the neem tree, native to India. This is an effective disease control and a broad spectrum, natural insecticide that is kinder to beneficial insects and mammals.
Water: Ironically, dry conditions and high humidity are the most favorable conditions for powdery mildew to form. But straight water is its enemy because it washes off the spores before they have time to embed. However, water isn’t something that I promote for control because wet foliage is friend to many other plant diseases.
Baking Soda (sodium bicarbonate): This is possibly the best known of the home-made, organic solutions for powdery mildew. Although studies indicate that baking soda alone is not all that effective, when combined with horticultural grade or dormant oil and liquid soap, efficacy is very good if applied in the early stages or before an outbreak occurs. Mix one tablespoon of baking soda with a teaspoon of dormant oil and one teaspoon of insecticidal or liquid soap (not detergent) to a gallon of water. Spray on plants every one to two weeks.
Potassium bicarbonate: Similar to baking soda, this has the unique advantage of actually eliminating powdery mildew once it’s there. Potassium bicarbonate is a contact fungicide which kills the powdery mildew spores quickly. In addition, it’s approved for use in organic growing.
Mouthwash: Generic, ethanol based mouthwash can be very effective at control. Tests using one part mouthwash to three parts water worked well for Jeff Gillman, Ph.D and Associate Professor at the University of Minnesota, Department of Horticulture. Just be careful when mixing and applying mouthwash as new foliage can be damaged.
Vinegar: Similar to mouthwash, the acetic acid of vinegar can control powdery mildew. A mixture of 2-3 tablespoons of common apple cider vinegar, containing 5% acetic acid mixed with a gallon of water does job. However, too much vinegar can burn plants but at the same time, higher concentrations (above 5%) are more effective.
Milk: The latest player in the fight against powdery mildew is milk. It’s not clear yet why it works so well, but it is believed that naturally occurring compounds in the milk are at work to combat the disease while also boosting the plant’s immune system. One experiment showed good results by applying a weekly dose of one part milk to two parts water. This is yet another case when more is not better. Concentrations above three parts water had adverse side effects.
A: Yes, they can be applied at the same time. It’s best to first do a soil test to check the pH (which measures acidity and alkalinity of the soil) to determine that lime is needed. A very low pH (below 6.0) means the soil is acidic, causing important plant growth nutrients to become “bound up” in the soil making them unavailable to the plant. Over time, liming will gradually raise the pH in your soil and free up these nutrients.
A: Probably. Try scratching the bark of the branches and twigs with your fingernail or a pen knife –if it is bright green underneath it will possibly re-foliate. If it is dull green or brown underneath, see if the twigs snap off, which most likely indicates they are dead. By this time you should see leaves.
A: The term “hybrid” refers to a plant variety developed through a specific, controlled cross of two parent plants. Usually, the parents are naturally compatible varieties within the same species. This hybridization, or the crossing of compatible varieties, happens naturally in the wild; plant breeders basically just steer the process by cross-breeding compatible types of plants in an effort to create a plant with the best features of both parents. These are called hybrids and many of our modern plants are the results of these crosses.
“Genetically modified organisms” or GMOs are created in a lab using highly complex technology, such as gene splicing. These high-tech GM varieties can include genes from several species — a phenomenon that almost never occurs in nature. GMOs can be any plant, animal or microorganism which has been genetically altered using molecular genetics techniques such as gene cloning and protein engineering.
A: That’s very possible, as mole tunnels can definitely make a lawn feel squishy!
Moles are kind of ugly, though you probably won’t see much of them, because they stay underground, feasting on their favorite food GRUBS (Beetle larvae).
The best way to get rid of the moles is to get rid of the grubs, either by applying Bayer Grub Control (24-hour or season-long) or by using Milky Spore, an environmentally friendly biological control that lasts for many years.
When the grubs are gone, the moles leave town, too!
A: Blackspot – a fungus that manifests itself on rose bushes as black spots on leaves progressing to black spots fringed with yellow rings on both sides of the leaves. As they develop the spots enlarge. Eventually, as the disease spreads, the entire leaves will go from green to yellow and then drop to the ground. With time the entire rose bush may become defoliated. New leaves are the most susceptible.
Blackspot is worst during wet weather, especially humid weather. The fungus becomes active in a wet environment with a temperature of about 75 degrees. It needs about 7 hours of these conditions to germinate and then symptoms will begin to appear on rose foliage within three to ten days. Spores can over winter in the garden so autumn cleanup is crucial otherwise the entire cycle can repeat itself the following spring and summer. Hybrid teas and smaller rose bushes be spaced 3 feet apart and larger rose bushes be spaced 4 feet apart from one another.
Preventative measures in early spring:
While plants are dormant in spring, spray thoroughly with fungicidal soap and wettable sulphur. Sulphur washes off in rain and so must be reapplied repeatedly. The product is sold in powder or liquid form and also works well against mildew and rust.
Keep the leaves dry when watering (try soaker hoses or drip irrigation methods):
Water in the morning so that foliage has a chance to dry off throughout the day
Prune plants to improve air circulation:
Space the plants well when planting will insure good air circulation. It is recommended
Preventative formula to minimize further attack:
Using fungicidal soap or sulphur several times over the course of summer is one solution (especially after rain as these products tend to wash off).
Some suggest these non-chemical controls, while other sources dispute their effectiveness:
Solution made with baking soda:
Dissolve 1 teaspoon baking soda in a quart of water, add a few drops of liquid soap to the mix to help it cling better to the foliage, spray infected plants thoroughly.
This formulation fights blackspot, as well as mildew and rust, while providing foliar nutrition. Place one gallon of well-composted manure in a 5-gallon bucket and fill with water. Stir the mixture well and let sit in a warm place for three days. Strain the mixture through a cheesecloth or mesh and use the resulting tea to spray disease affected plants (the solids left behind can be applied around the base of the plants as added fertilizer).
This oil has been reported effective by some.
A: If you’ve planted any annuals, tender vegetables, perennials or shrubs with tender growth, covering them with an old sheet or a bucket will help protect them from cold damage. If they’re in (movable) pots, bring them into the garage or house to protect them. Be sure to uncover/bring them back out tomorrow. Any established plants will be fine, although you might lose new flowers.
A: There are various insecticides that will kill ants, but here are some natural ways I picked up on the internet that you may want to try first:
Predators Ground beetles, humpback flies, parasitic wasps, praying mantids and the yellow-shafted flicker all dine on ants. Woodpeckers are voracious ant eaters. You may see them also pick up ants in their beaks and crush them on their feathers. What are they doing this for? Crushing the ants bodies releases tannic acid which in turn protects the bird from parasites!
Here is something interesting: it is said if you take a shovelful of ants from one hill or nest and put it in another ant hill then take a shovelful from that hill and put it where you took the first one the ants will then wage war on one another and do themselves in!
Repellent plants Catnip, pennyroyal, peppermint, sage, and spearmint. Tansy which is often recommended as an ant repellant may only work on sugar type ants. These are the ones that you see on peonies and marching into the kitchen.
Warning: You do not want to plant Tansy anywhere that livestock can feed on it as it is toxic to many animals. Do not let it go to seed either as it may germinate in livestock fields.
Barriers Sprinkle leaves and flowers from sage, mints or tansy around the outside of your house or plants that are bothered by ants. These plants can also be used as a living barrier for ant control, bearing in mind that they are invasive in their growth habit and using cuttings from these plants as a barrier is more effective. We grow tansy in an out of the way place to harvest the cuttings.
To make teas:
Take enough cuttings from these plants to tightly pack one 8 ounce cup. Bring 1 quart of water to a boil. Stir in the plants. Take off the heat and allow to cool. Strain this mixture, add 1 teaspoon of castile soap and use as a direct spray. You can also substitute 1 teaspoon of coconut oil soap in place of the castile.
Pyrethrum mixed with isopropyl alcohol kills ants on contact. Take 16 ounces of ready to use pyrethrum, mix in 1 tbsp. alcohol. Use this as a drench directly on the active nest.
Boric acid: Mix 1 cup of sugar, 4 teaspoons of boric acid and 24 ounces of water in a glass screw top jar. Shake thoroughly until you can see that all the crystals are dissolved. Now put 1 cup of this mixture into a smaller jar which you have filled halfway with loose cotton. Firmly screw the lid back on, seal around the band with weatherproof tape and using an awl punch a few small holes in the center of the lid. Put this near the entrance of the nest or wherever they have made a path to your house. The key is the ants will get into the jar to eat the sugar and return to the nest and pass it on to the rest of the colony. If you find many dead ants by the jar dilute the solution and try again. With a proper mixture the colony may be destroyed in a few weeks. It does take the destruction of the queen to completely eradicate a colony. Keep this away from kids and pets!
Here is another ant bait recipe:
Mix three parts peanut butter with two parts jelly and add one tablespoon of boric acid per six ounces of mix. Place the bait on pieces of paper so stuff it into large straws and place where you see the ants foraging. Again keep out of the reach of pets and children
A: We carry “cold vegetables” in a 6” pot for $3.99 – these veggies can be planted now, and withstand temperatures down to 25o : Arugula, Asparagus, Beets, Brussels Sprouts, Broccoli, Cabbage, Cauliflower, Collards, Kale, Lettuce , Ming Quin Choi, Pak Choi, Spinach, and Swiss Chard.
Seeds can be planted after the danger of frost, preferably when the soil warms up just enough to keep the seeds from rotting. Every seed packet tells how long it should take for the seeds to germinate. Some gardeners prefer to get a jump on the growing season by planting their seeds indoors in trays and keeping them in bright light until they start to grow. Then when we are past the danger of frost the seedlings can be planted outside, with several weeks of growth beyond what they would have if seeds were planted outside at that point.
A: Organic gardening means using growing techniques that rely on materials and approaches that are certified organic by the USDA, which is the main regulating body in the United States for organic certification.
They generally use only certified chemicals at the correct dosages. Common organic agriculture chemicals include BT and copper fungicide. These chemicals have been extensively tested and pose less threat to the environment than stronger synthetic chemicals.
It’s important to note, however, that an “organic seed” will not necessarily produce an organic plant. An organic seed will merely produce a seedling that came from organically grown parent plants.
Though our seeds are not certified “organic” (which generally means they have come from organically grown plants), the seeds we sell are non- GMO. [NOTE: In genetic modification (or engineering) of food plants, scientists remove one or more genes from the DNA of another organism, such as a bacterium, virus, or animal, and “recombine” them into the DNA of the plant they want to alter. By adding these new genes, genetic engineers hope the plant will express the traits associated with the genes. ]
A: It is safe to plant hardy outdoor trees and shrubs now! Though we may still get periodic dips in the temperature, they should survive without a problem. However, plants with fresh growth can be “tender” and will have their new soft growth damaged by the cold. This will not affect the overall plant survival but the damaged tips may have to be snipped off. If you are planting something with tender growth or have something in your yard that has started growing already, it’s a good idea to monitor the weather and cover your less hardy items for a few cold nights!
A: We are receiving new shipments daily. What we receive often depends on what the grower feels is ready to ship based on size and quality! This year we are a little behind schedule due to so many weather events in the growing areas.
A: Yes! Late winter (right now) is the best time to prune a crepe myrtle, because it’s leafless and you can easily see all of the branches. It also blooms on new growth, so pruning now won’t reduce blooming. In fact, it may increase it.
A: We carry corn gluten which would be the safest pre-emergent for both kids and pets. Corn Gluten is an all-natural by-product of the production of corn starch, and works by preventing the development of weed seedling roots.
A: First ALWAYS READ THE LABEL! The information you find there supersedes any other information!
That being said, it should not be a problem to mix pre-emergent with weed-and-feed, but it is important to note any stipulation about seeding your lawn after applying pre-emergent, as the pre-emergent will either prevent seed germination, or keep the seedlings from taking root!