Phlox Fall Care Essentials!

The fall colors of decaying plants are surprisingly pretty long into winter.  They brighten the garden and make the transition to winter's browns easier. I leave most of the wildflower seed heads standing until late winter at Clay and Limestone.  After all, I garden for wildlife and goldfinches feed on the coneflower, rudbeckias, agastaches; the grasses provide cover for small critters; and, I like how it looks. But, I never let the summer phloxes stand all winter.  Once they've gone to seed and browned, I cut them to the ground.

Ready to be cut to the ground

 This is an essential first line of defense against the Phlox Plant Bug. 

This is the nasty critter with proboscis in use

Lopidea davisi is a plant juice/sap sucking insect with a long proboscis and that feeds mainly on perennial phlox. The clever little adults lay white-coloured eggs in the fall in stems of the plant, behind the leaf petioles.

Phlox after a frost is still pretty, but it has to go. There might be bug eggs hiding!

The eggs overwinter and nymphs emerge in early May. Two or more generations could develop in a season.  Hoky Smokes! You can see how it wouldn't take long for them to get well established in the garden. Cutting the plant to the ground and destroying the dead stalks and leaves is essential!

The bug feeds on leaves, stem terminals, flowers and seeds

This is not a pest to ignore. They can form dense populations and suck the life juices (sap) out of your plants.  Take a look at the photo from the Missouri Botanical Gardens.  This is in the early stages before the Phlox Plant Bug has gotten horridly out of control!  As you can clearly see, feeding causes light green/white spots on the leaves where the plant's juices have been sucked out!  Later in the season, leaves stipple yellow, turn brown, curl, dry out and drop. The plant often becomes stunted and dies.

Phlox Plant Bugs are tiny; less then 1/4 inch, fast moving critters that hide underneath leaves and make it hard to see and smush!  As far as I know, they don't seem to be a tasty treat for the beneficial insects or birds that visit my garden.  Perhaps, their orange and black coloration signals~"Stay away" to most  insect eating critters.   

Phlox is a foundation plant at Clay and Limestone.  It was here before me and I hope it's still here after I leave this garden. In the meantime, I will do what I must to keep the garden free of Lopidea davisi without resorting to the big gun pesticides.

• 1. Practice good sanitation. Cut back and dispose of infested stems and leaves. Clean up stem and leaf litter in the winter. I cut back every stem I find and threw them in the trash, not the compost. Compost works if yours gets hot enough to cook bugs! Mine doesn't.
• 2. Scout for nymphs and treat. Apply insecticidal soap to both the upper and underside of the leaves. Use a light horticultural or sunspray oil. I haven't had to up my tx to this.
• 3. I never, ever, ever, ever use pesticides in my garden... whether or not they are recommended  in the Integrated Pest Management program. I love my bees and other pollinators and don't want to risk causing them harm.

I hope this pest isn't in your garden.  It's a known problem in the eastern US and some Midwestern states. Canada, you aren't exempt! Even if it's not a problem, go ahead and trash the decaying phlox.  Trust me, this will go a long way to ensure it won't become one.  It worked in my garden.

xxoogail

Gail Eichelberger is a gardener and therapist in Middle Tennessee. She loves wildflowers and native plants and thoroughly enjoys writing about the ones she grows at Clay and Limestone."