This time of year gardeners are seeing powdery mildew and spider mites on roses, as well as rust. The easiest, organic solution is to wash off the leaves early in the day. Powdery mildew spores cannot live in water, spider mites likes plants that are dry and dusty. Washing off the leaves every few days is labor-intensive and uses lots of water. Serenade, one of Sloat’s newer products, is OMRI listed (more on that) as a fungicide. The active ingredient is Bacillus subtilis QST 713, a naturally occurring soil microorganism. It works in several ways; first it creates an ‘inhibition zone’ on the leaf preventing pathogens from attaching, secondly, it stops pathogen growth by competing for nutrients and space on the leaf, and lastly, it’s bacterial cells and lipopeptides destroy germ tubes and mycelium membranes. Serenade can be used up until day of harvest for Bacterial Leaf Spot (escallonia), Powdery Mildew, Rust, Leaf Blight, Black Spot, Fire Blight on melons, tomatoes, apples, roses and more. Check out the label on our newest earth-friendly solution for rose disease problems.
Roses still need deep, regular water, even if it has been foggy. Fog is not the same as rain. Roses can continue to bloom if watered, until October. August is also the last month to apply a granular organic fertilizer to roses (alfalfa, EB Stone’s Rose and Flower). Organic fertilizers typically take 4-6 weeks to break down to the point that rose bushes can absorb the nutrients. The fertilizer cutoff for roses is September 15.
Another earth-friendly solution we carry is Victor Poison Free Ant Control and Victor Poison Free Yellow Jacket Control. The Ant Control’s active ingredient is mint oil, and ALL of the inert ingredients are listed as well and carries an OMRI listing. Shake the can upside down for 15 seconds, then spray the buggers, mmm, minty fresh! The effect lasts up to 4 weeks. This spray contains no CFC’s, the propellant is carbon dioxide.
The Yellow Jacket Control’s active ingredient is mint oil again, the inert ingredients are mineral oil, lecithin, carbon dioxide and water.
As with all spray products, avoid getting the product on skin and eyes.
OMRI stands for “the Organic Materials Review Institute, a national non-profit organization that determines which input products are allowed for use in organic production and processing. OMRI listed or approved –products may be used on operations that are certified organic under the USDA Organic Program.” www.omri.org