Lately the media has been all about the Brood X cicada hatching. I am fortunate that they do not make it far enough north to trouble me (one of the very few benefits of living in the frozen north–we do not get any sort of periodical cicadas, just the ordinary dog day kind).
But of course, that doesn’t mean we don’t have insects. And Memorial Day weekend is just about the time when we start having insect damage. This year has been a bit unusual because the weather has alternated between unusually cool weather and unusually warm weather. So the cool weather insects are trying to hang on a bit and the warm weather insects are here too. It’s like an insect bonanza on the plants–although I am sure they don’t think so!
For example, aphids, which are normally a cool season insect on roses, are still here. They rarely hang around this long.
And this damage indicates an insect that is just about invisible to the naked eye–the rose sawfly larva. It’s a caterpillar-like creature that is nearly the same color as the rose leaf and it sucks the juices from the leaf–that’s what the little scrapes on the leaf are.
Luckily, up here in the frozen north, we only have one generation of them a year so I do no type of organic control on them at all. They can really disfigure the leaves a bit, but it’s only for a couple of weeks, and then the shrubs put on some nice new growth and all is well.
And this cute little semi-circle is made by the leaf cutter bee. They take out the leaf parts to line their nests in hollow wood. They are native pollinators so it’s important not to use chemical pesticides on your roses–and that includes those “wonderful” systemics that they sell that do everything from kill insects to keep fungus away.
What do you think is harming the pollinators? Please stay away from stuff like that! If public rose gardens can manage themselves organically, so can you!
I find that the same insects recur at the same time yearly. Once you know what to look for, it’s almost as easy as predicting when those periodical cicadas will be back.
The Santa Clara Valley happens to be one of the best places in the World for roses. I have always grown roses, but have never needed to spray them with ‘anything’. No one believes that, or course. The main problem with roses, as well as fruit trees in home gardens, is that they do not get pruned aggressively enough to regenerate vigorously.
I know that fruit trees need a lot of pruning to bear fruit and do it well. That’s one place where home gardeners are generally at sea (if you avoid the horrible mixed metaphor) because they do want to learn but there aren’t a lot of places to learn basic home pruning.
Whenever I talk about it, they don’t know the difference between anvil and bypass pruners and what each is used for. So there’s just a huge gap of knowledge–and of course no one is going to hire someone to prune small trees when they can reach up and clip a branch. And the rest is history.