It’s the first day of September and in addition to being the first official day of school here in Stamford, it’s also time to post my monthly Gardening OOPs (GOOPs) story. The inspiration for GOOPs comes from Joene Hendry, the author of the blog joenesgarden . I think I’ll follow along with Joene’s theme of her September GOOPs - letting your guard down.
This year I’ve had two fairly major issues with insect infestation that I should have discovered much earlier than I did. And because I let my guard down, I will probably have to remove a lilac bush that is about 10 years old, leaving a gapping hole in my shrub border.
My first infestation was with sawflies on my red twig dogwoods. Rather than going into all the nasty details about that problem (I don’t consider myself a squeamish person but there is something completely disgusting about handpicking sawfly caterpillars off of a shrub and drowning them in soapy water), you can read about Joene’s sawfly infestation since it sounds like her’s happened at about the same time and eerily mirrored mine in how it unfolded.
My second infestation is with beech scale and I am fighting it now. A few days ago I noticed some dead leaves on one of my lilacs – I have four lilacs planted together in the far corner of my garden – but I didn’t go to investigate. Instead I filed the observation away in mind and thought ‘the next time I have my pruners out I need to remember to clip off those dead leaves’. The lilacs have been growing in that same spot for at least 10 years and other than the typical case of powdery mildew, they have never had any serious issues.
I finally got around to investigating the dead leaves and what I found was a nasty whitish-yellow fungus growing on the branches of some of my lilacs. The leaves are basically untouched but the branches look like they are wrapped in dirty wool. Two of the lilacs are so heavily infected I have to wonder how long the infestation has been going on. If I’d investigated the dead leaves sooner could I have prevented the infestation from getting so bad?
Since I had no idea what was happening and I was afraid the infestation would spread to my beloved ‘Miss Kim’ lilac, I clipped off a few branches and headed over to the Plant Clinic at the Bartlett Arboretum. Several times a week, the master gardeners at the Bartlett are available to help local gardeners answer questions about what might be happening with their plants. It’s a great, free resource available to any gardener within driving distance of the Bartlett and one that more and more gardeners are starting to take advantage of.
To make a long story short, the master gardeners were as stumped as I was and told me they’d call me once they had confirmation on what is attacking my lilacs. According to the return phone call, the official cause of the infestation is beech scale eggs. I was told to cut out any infected wood, dispose of it , clean up all debris under the lilacs and then spray the lilacs with horticultural oil in the fall and again in the spring before they leaf out. Left untreated, the eggs will eventually hatch into scale insects and most likely kill the lilacs and any other plant they attack.
I think this means I will basically lose two lilacs in order to save the remaining two. While I’m happy to sacrifice two shrubs to potentially save all the others around it, I can’t help but wonder how I missed the early signs of the infection. I guess the lesson to be learned is that it’s important to check all your plants on a regular basis, even the mature ones that typically don’t have any issues. It’s easy to get side tracked by the seemingly endless care that perennials demand. But thinking about it now, I’d much rather replace a perennial than a mature shrub.
