By Jodi Torpey
Last summer I stepped onto the back patio, looked at the snowball bush and wondered, “What the heck is wrong with this shrub?” The leaves had been chewed so completely, only the veins remained. After a little research I identified the insect pests as hungry Japanese beetles.
The next time you spot foliage problems on your favorite plants, use the leaf damage to uncover what’s bugging them. Here’s what to look for:
Notches in foliage? It’s probably the feeding damage caused by lilac root weevils. These notches appear along the margins of leaves, almost as if the insects used pinking shears to cut zigzag edges.
Lilac root weevils hide near the base of plants during the day and then crawl up the stems to feed at night. One way to control these insects is to place sticky barriers on plant trunks to prevent the pests from getting to the leaves.
Another way to control lilac root weevils is to hunt them at night with a flashlight and a container of sudsy water. If you’d prefer not to touch them, place a tarp on the ground and shake the branches so the weevils fall off, then drown them in the bucket.
Small, buckshot-like holes? Flea beetles leave small, round holes on the tender leaves of vegetable plants. These little black beetles show up early in the season and can damage or kill seedlings and young transplants.
To prevent flea beetle damage, cover plants with lightweight row-cover cloth, and tightly tie it down at the edges with soil or boards. Leave the cloth in place until plants grow large enough to withstand some flea beetle damage, or when the first rush of insects ends in late spring.
Lacy leaves? Japanese beetles are to blame. These shiny, blue-green insects start showing up in June. Japanese beetles feed on tender foliage, resulting in leaves that look like skeletons, right. Because these pests attack in groups, they can cause a lot of damage quickly.
To control Japanese beetles, look for them on plants in the early morning or at dusk. Pick insects from leaves, or shake them into a bucket of soapy dishwater. Dispose of the water away from planting areas.
Paper-hole punches in leaf edges? Not all leaf damage is created equal, and not all damage results from pests. Circular snippets—looking like paper-hole punches—cut from rose leaves are the work of native leaf-cutter bees, some of the garden good guys. Leaf-cutter bees use these round leaf wrappers to line the cells of their nests.
When you see this type of damage, it means some baby leaf-cutter bees are on their way, and you can congratulate yourself on the new additions to your garden.
It pays to spend time looking for leaf damage, so you can take action quickly to protect plants. What kinds of leaf damage have you seen in your Mountain region landscape?
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