Pests are back: Powdery mildew, Japanese beetles

Posted by tonka_admin on Jul 13th 2017

July is a month of fun and exciting activities and new discoveries. This is one of the best times of the summer to visit the arboretum, go on garden tours, and see gardens and containers at their prime. Now is the time to get out there, gather some inspiration, and get gardening! Unfortunately this is also the time when pests and disease come calling. This is where the down and dirty, behind-the-scenes work of maintaining beautiful gardens and landscapes comes in. Here’s what to do about a couple of the most common (and frustrating) problems plaguing gardeners right now.

Powdery mildew

The spores responsible for powdery mildew are in the atmosphere all the time, but it’s when conditions are just right that they begin to take hold and show (and conditions have been favorable lately). Several different plants are particularly susceptible to powdery mildew: cucumber, zucchini or summer squash, peonies, bee balm, dahlias and phlox, to name a few. First things first: know how to identify the disease. It appears as somewhat fuzzy-looking, white splotches on leaves and stems of plants. Sometimes, severely damaged leaves will begin to fall off, too.

What’s a gardener to do?

Identify the problem as soon as possible. Any treatment will not reverse the effects of powdery mildew, but it will stop it from spreading any further. Powdery mildew likely won’t kill plants, but it is unsightly. The sooner it’s caught, the higher the chances of stopping it in its tracks. Treat plants with Bonide Copper Fungicide spray, being sure to spray all leaf and stem parts. Generally, blooms are not affected by powdery mildew, so for pollinator safety avoid spraying the blossoms.

Japanese beetles

What can we say? These bugs are disgusting, just plain gross. They are destructive and excel at making gardeners miserable. They do have some favorite foods, but recently any brief discussion with fellow gardeners reveals that some of them may be expanding their palate. Their favorites include roses, raspberries, grape vines and linden trees. They’ve been seen on dogwood and echinacea recently, too, though.

What’s a gardener to do?

Know thy enemy. Be out there, be watching. Know how to identify the beetle and the damage they cause (they eat leaves, making them nothing more than lacy remnants. They eat blossoms, too.) Knock down the population. They shoot eggs out while flying (like nasty little projectiles that silently lie in wait to destroy your garden next year). Don’t delay in taking care of them, it just gives them time to increase their numbers. Truly, one of the most effective ways to take them out of commission is to hand pick and toss them into a bucket of soapy water, or just tap them in. If possible, do this a couple times a day when they first emerge, because new beetles are continuing to hatch and appear at this time. Just put on a brave face, give yourself and your plants a pep talk, slip on some gloves and grab the bucket. You can do this. Alternatively, spray Japanese beetles with an insecticide. Bonide makes several effective products: Japanese Beetle Killer, Eight, and Captain Jack’s Dead Bug are all good choices. Be sure to spray very early in the morning or late in the evening when pollinators aren’t foraging, avoid spraying blooms for pollinator safety (if possible, enclose blooms in baggies for extra protection), and try to hit the beetles directly. Beetle baggers are another option. It’s true that the bagger attracts beetles, so your neighbor’s beetles might end up in your yard. However, the point is to place it away from their favorite plants to lessen the damage and kill the beetles.

General tips

Make note of the timing of garden pests and disease. Where is the problem? When did it first appear? What worked and what didn’t in attempting to fix the issue? Next year, review your notes at the beginning of the season and be ready to tackle any issues. These things generally happen within a couple weeks of any given season before or after. Bee careful, bee safe. Keep our pollinator pals in mind when choosing what and how to treat problems. Don’t become too disheartened over bug and disease problems. They're unfortunate, but you’re not alone it’s just part of the process of gardening. Plus, we’re here to help! If you have any questions, contact the experts at Tonkadale Greenhouse. We're always happy to help!