Plenty of customers & clients are telling that they are having trouble with two unattractive fungal issues this spring: powdery mildew and sooty mold. Here’s what you need to look for so you can avoid (or minimize) the effects on your plants by catching the problem and treating it early.
Symptoms: White or gray fuzzy coating on the upper side of leaves and sometimes stems. Commonly seen on roses, monarda (bee balm), crape myrtle, and garden phlox, though it can affect almost any plant. Severity can range from isolated spots to compete coverage of affected areas.
Caused by: Moderate temperatures and high humidity but low rainfall encourage powdery mildew growth. Spores of powdery mildew are widespread in the air and soil and will attack susceptible plants when conditions are favorable.
Impact: In most cases powdery mildew will not kill a plant outright, but can be very cosmetically damaging. Leaf distortion and yellowing or other discoloration is common, and it can promote bud loss on flowers. Severe cases or cases that begin early in the season and persist long-term can weaken a plant, or prove to be the fatal blow to an already weakened plant.
Treatment: Powdery mildew can be managed but rarely eliminated once it starts. Preventive sprays may be worthwhile for susceptible plants. Once the fungus is observed, treatment must be applied regularly for as long as conditions are favorable for development. Products containing chlorothalonil, propiconazole, or neem oil (organic). Home remedies that work include baking soda sprays (1 tablespoon of baking soda and 1 teaspoon of insecticidal or dish soap-do not use detergent-in a gallon of water. Spray every 7 to 14 days) and solutions of milk (one part milk to two parts water, sprayed every 7 to 14 days).
Symptoms: Black coating on upper side of leaves. It may appear as a dark haze, or be thick enough to turn the leaves entirely black. It has a dry appearance, not slimy or sticky. It may appear on the top growth or the lower growth of the affected plant. It can appear on any plant.
Caused by: Sooty mold is a fungus that grows on “honeydew”, the excrement of insects like scale, aphids, whitefly and mealybug. For some cryptic insects like scales, sooty mold may be the first indication that there is an infestation.
Impact: Mostly cosmetic, as the fungus does not invade plant tissues or cause direct damage. However, the coating can restrict sunlight from reaching the leaf and reduce the ability to photosynthesize. This is generally only a problem for already weakened or sick plants.
Treatment: Look at plants above the affected plant if sooty mold is found on the upper part of the plant, or at the upper growth of the same plant if affected leaves are at the bottom. You will undoubtedly find an infestation of one of the insects mentioned above. Treat the insect problem and the mildew growth will stop. (Specific treatment will be determined by type of insect found.) The mold itself is difficult to remove and usually needs to be left to weather off naturally, or be covered by new growth.
Ugh! What’s nastier than a sack of crawly caterpillars hanging from your trees? How about a dozen of ‘em?
Quick tips for avoiding the fungal disease Brown Patch in lawns
Blueberries make great container plants! Watch this video from our friends at Espoma for tips and see how easy it is to grow blueberries in containers.
Good container plantings require little maintenance aside from watering and can enhance your home through the spring, summer, and fall.
Unlike some other flowering plants, crapes will develop their flower buds on new growth.
With over 1,700 different species, Begonias (family Begoniaceae) is the fifth most diverse class of plants.
Organic methods can be very effective when used preventively or before pest populations become too large.
Is your forsythia starting to bloom for Christmas? Here's why some plants flower during warm winter days.
This is a question we have been asked frequently this fall.
Where and why this is not bad advice, and where it’s a terrible idea.
Plant some of these low-maintenance (and critter resistant) spring bloomers this fall.
Don’t wait until your summer annuals give up the ghost to plant your fall pansies!
Don't cut too much if you decide to tidy up your crape myrtles in late summer and fall!
It looks like someone Silly Stringed your garden, but it's actually a whole lot weirder.
Rose sawfly is a common pest of roses. Identifying rose sawfly damage is important to select the best control methods.
There is a method to insure that you can have fresh cilantro all summer.
Camellias are relatively unfussy and problem-free shrubs, but they can develop camellia leaf gall, a unique and odd-looking disease.
Here’s how to manage-and maybe even prevent-an aphid problem in your landscape.