Our typical hot weather is here and unfortunately, we are not even seeing a short knock-the-dust-down type of shower. Gardeners though, continue to persevere through it all, and call and email me with questions. So what’s being asked?
As you would expect, insects are the big deal. A constant inquiry from everyone has been the elm seed bug, which we started seeing in 2015. This insect loves to come indoors, and who can fault it in our hot temperatures? Controls start with tightening up the house, as is the case with other house-loving insects. Seal cracks, weather strip doors and windows, have tight window screens, but realize some will still come in. Having elm trees around the house doesn’t help but maybe next year clean up the seeds which they feed on. If insects are on the outside of the house, spray with a soapy water solution or an insecticide, but it’s not a cure-all and won’t kill them all. Here at the office I use a good hand vacuum and periodically go around vacuuming them up.
An insect we usually have but which appears to be worse this year is thrips. Thrips are very small slender insects about 1mm long. They move quickly, and being so small they often are just barely glimpsed. They damage flowers so they don’t open well, scar fruit such as nectarines, and will damage the leaf surface of annuals such as marigolds so it looks like the green or chlorophyll has been scrubbed off parts of the leaves. While some of this is cosmetic damage, the fruit scarring or damage to flowers is more of a problem. For now, thrips on annuals or perennials can be sprayed with a soapy water solution as a quick knock down, and with spinosad, found in organic formulations, for a bit longer control.
One of this year’s interesting insect situations started with calls about holes in the leaves of ornamental sweet potato vines. This plant is often found mixed with flowers in planters and it comes in a variety of colors from light green to dark purplish. Now it’s common to see holes made in plants by caterpillars and various types of beetles and not uncommon to see holes in leaves, especially delicate leaves, caused by the wind. In this case, the answer presented itself in one of the pictures that was sent to me which showed a paper wasp on one of the leaves. It turns out that paper wasps really like these leaves, being quite delicate and soft, and they cut holes in the leaves, then chew them up to use to build their nests. I mean, how interesting!! Again, it’s a cosmetic issue and while you don’t want paper wasps around where you work and play, they are beneficial insects since they attack other problem insects.
Finally, and I know you hear this from me a lot, but while plants are awesome they aren’t magic. The less stress they deal with the more they can handle insects and diseases. The biggest stressor here is inadequate irrigation. Water is precious but so are plants. They help make life worth living, and besides the basics of oxygen, shade, and sound absorption, research shows quality landscapes and trees lessen mental health issues in communities, so keep planting and care for them properly!
Previous articles can be found on The Times-Independent website. If you have a topic you would like to know more about, call the Utah State University Extension Grand County office at 259-7558 or email Mike at [email protected]
ByBy Michael Johnson
Utah State University Extension Agent, Grand County