Today: Sep 19 , 2018

Identify and Cure Powdery Mildew
Featured

That “white powder” that covers leaves.  Identify, Control, Prevent Powdery Mildew on Plants.   

Powdery mildew is one of the most prevalent and easily recognized plant diseases of our rainy season, from July to the end of October. Virtually no plant is immune, but some are more susceptible than others.  Lilacs, crab apples, phlox, monardas, roses, grapes, squashes, and cucumbers are likely targets for this powdery pest. 

Recognizing Powdery Mildew - Take a close look at this photo of a squash leaf in my garden.  Powdery mildew looks like splotches of white or gray powder on the leaves and stems of plants. There are several types of powdery mildew fungi, but they all look the same. You may not notice a problem until the top surfaces of the leaves turn powdery, but powdery mildew can also affect under- leaf surfaces, stems, flowers, buds, and even the fruits of plants.

Although powdery mildew is unattractive, it rarely is fatal. It does stress the plant, and severe or repetitive infections will weaken a plant's health. If enough of the leaf surface becomes covered with powdery mildew, photosynthesis is impaired.  Infected leaves often drop prematurely. This can be a particular problem on edible crops since insufficient photosynthesis can diminish the flavor of the fruit or vegetable. If buds become infected, they may not mature or open at all!

Mildew is Host Specific - Powdery mildew fungi are host specific, meaning that different powdery mildew fungi infect different plants. The powdery mildew on your lilacs will not spread to your grapes or your roses. . .

Cause and Effect -  Powdery mildew fungi seem to be everywhere. They overwinter in plant debris, and begin producing spores in the spring. These spores are carried to our plants by wind, birds, insects, and splashing water.  All powdery mildews thrive in the same conditions. The growth and spread of powdery mildew is encouraged by dampness, high humidity, poor air circulation, and crowded plants in the garden. In the mountains of Arizona all of these conditions appear at the start of our monsoon season! 

Controls – First and foremost choose healthy plants.  Healthy plants are less likely to become diseased and are able to fend better for themselves if an attack happens.  Good to know that there are plants being bred to be more resistive to mildew.  Whatever you do, don't plant non-resistant varieties in shaded areas with poor air circulation! 

Infected Plants – Just a little attention and care will fend off pesky powdery mildew.  Remove and destroy all infected plant parts, especially yellow leaves and those that are mostly covered by the white spores.  Because powdery mildew favors young, succulent growth, don't fertilize until the problem is corrected.   Try to water infected plants at ground level to keep leaves as dry as possible.

Fungicides simplified -Spray the entire plant from top to bottom with a good fungicide.   For continuous protection most fungicides will need repeat applications every 7 - 14 days. Always follow the label instructions for both implementation and the waiting period before harvest. 

Organic controls -  Early prevention is best done with Triple Action organic spray by ferti-lome.  Spraying an infested plant with this neem-based liquid not only kills that specific spore and prevents its spread, it also eliminates small insects like aphids, thrips, and mealybugs. 

Edibles coated in white mildew will need something stronger.  Clean up yellowed, infected leaves of fruit and vegetable plants as best you can, then spray with 100% organic 'Copper Fungicide'. It may be applied moments before harvest.

Seriously infected plants need  Bonide's 'Infuse'  , the most powerful fungicide you can buy over the counter. Use it on plants like roses, lilacs, vincas, and privets for quick relief.  Be aware that it is not rated for garden edibles.

Spray at least every other week until new leaves emerge clean and disease free.  At this stage feed your plants and they should take off with new growth. 

If you just aren't sure about treating powdery mildew, consult one of the plant experts here at Watters Garden Center.

All products mentioned in this article are available here at the garden center with a knowledgable staff on hand to guide you in their use.

Please – Powdery mildew spreads very easily to other plants.  If you are bringing a leaf sample with you to Watters, please place it in a ziplock bag or a jar to contain the spores and prevent spreading here at the garden center. Thank you.

See samples of Powdery Mildew from local gardens on Watters Pinterest Board,  Follow our board for local updates. 

Watters: Website | Facebook | YouTube | Instagram | Pinterest

Gardening Classes

Sept 1 - Gardening for Newcomers  

New to northern Arizona or just new to gardening? This class is Gardening 101 for everyone hoping to turn a brown thumb green. Learn all the mountain secrets to local garden success from soil preparation and planting to watering and fertilizing. This is an information-packed class guaranteed to increase blooms and fruit this year and reduce frustrating gardening mistakes!  

If you can't attend this class, watch the Livestream on Facebook. Like our Page to be notified when we go Live.

Sep 8 - Secret Gardens with Hedges & Privacy Screens 

Beautiful mountain views on one side, neighbor's RV on the other? This class shows off the best, fastest growing plants to fill in for privacy screens! You can screen unsightly neighbors, enhance your view, or block pesky traffic and cut noise and light pollution.   Experts will be on hand to help individuals with unique situations. FREE

If you can't attend this class, watch the Livestream on Facebook. Like our Page to be notified when we go Live.

Sept 15 - Wildlife & Bug Prevention

Late summer is not only the peak of bug season, there's also intense pressure from furry visitors in our yards.   Students start with best practices to keep javelina and pack rats away, then quickly move to solutions for grasshoppers and tomato worms.   You can have a nice yard with these easy-to-use tips and a few key plant choices.   Frustrated gardeners will have all the tools they need to keep the garden pest free! 

If you can't attend this class, watch the Livestream on Facebook. Like our Page to be notified when we go Live.

Sept 22 – Fruit Trees – Health and Harvest 

Fruit trees not only beautify our landscapes, they give us actual food to eat! This class focuses on which varieties are the best for our community, how to care for them, and how to get your best bounty ever. We'll take you season by season through the year-round practices that produce results for the best health and biggest harvest you've ever had.

If you can't attend this class, watch the Livestream on Facebook. Like our Page to be notified when we go Live.

Sept 29 – Planting for Success in our Mountain Soil 

We've planted thousands of plants throughout northern Arizona, and now we're going to share our secrets with YOU. Watters' Planting Manager, Ella Amos, gets her hands dirty every day planting new landscapes for our wonderful customers. Years of planting success and the knowledge she's gained through her experience make Ella the perfect Guest Instructor for this class. She'll share the techniques and trade secrets she's learned to help you be a smarter, savvier, more successful gardener.

If you can't attend this class, watch the Livestream on Facebook. Like our Page to be notified when we go Live.

October 6 –   Irrigation in the Waterwise Landscape

Irrigation systems can confound even the most experienced gardeners! Learn the benefits of drip irrigation, the best emitters and parts, and how to set a system up or add to it.   With the right system, you can save water and have healthier plants at the same time.   Students will also learn which plants are considered “waterwise,” and how to grow a beautiful landscape while saving our most precious resource – water!  

If you can't attend this class, watch the Livestream on Facebook. Like our Page to be notified when we go Live.

Oct 13 – Top Trees for Fall and All  

Privacy, shade, color, evergreen, and blooms – trees are the foundation of the landscape! With so many choices, picking the perfect tree can seem overwhelming, but not after this class. Students will learn which trees are best for their garden wish list, and which can provide stunning, year-round interest when planted together. Our horticultural team will be on-hand after the class to help with individual tree situations. 

If you can't attend this class, watch the Livestream on Facebook. Like our Page to be notified when we go Live.

Oct 20 – Container Designs – Easy as 1-2-3  

The fall plants have arrived, and this is the month to transition from summer blooming flowers to winter hardy pansy, viola, mums, kale, dusty miller and more.   Expect inspirational color from your container gardens right through the holiday season to come. Students learn the best soils, foods and flowers that keep on blooming.   Bring your empty containers and experts will be on hand after the class to help personalize your style.

If you can't attend this class, watch the Livestream on Facebook. Like our Page to be notified when we go Live.

Oct 27 – Winter Wellness – How to Keep Plants Healthy in Winter 

Which plants need to be brought inside for winter? What's the best way to keep them healthy when they're brought inside? How do I protect the plants in my garden from frost? Do I have to water in winter?   We'll answer all these questions and more in this winter preparedness class. Learn the best practices for helping your plants through the chilly winter months so they can be at their best in Spring.

If you can't attend this class, watch the Livestream on Facebook. Like our Page to be notified when we go Live.

Nov 3 – Fall ‘To-do‘ list for a Healthy Yard 

Get the most out of your landscape with this easy to use checklist of fall care.   Bring the color out of your fall gardens, reduce bugs next spring, or simply put your landscape to bed with these easy to use ideas.  

If you can't attend this class, watch the Livestream on Facebook. Like our Page to be notified when we go Live.

 

 

K2_TAGGED
Ken Lain, the Mountain Gardener

Ken Lain is attracted to sunshine, beauty, happiness, success and health through gardening, and wishes to point the way to others. Throughout the week Ken can be found at Watters Garden Center located at 1815 W. Iron Springs Rd, Prescott, or contacted through his web site at www.wattersgardencenter.com

Website: www.wattersgardencenter.com