If you’re looking for a low maintenance, low growing perennial that likes both full sun and shady gardens, Bergenia might do the trick.
This Asian member of the Saxifragaceae family has large paddle-shaped evergreen leaves that can turn reddish during the winter or in full sun. Slowly spreading from rhizomes that are easily divided, they grow in clusters. From the center of each plant, a thick flower stalk emerges in the spring topped by a spray of medium sized white, pink or red flowers.
Bergenia are pretty disease resistant, but they can fall prey to root weevils. A sure sign weevils are at work are leaves whose edges look like they’ve been trimmed with a pair of banged up pinking shears.
If this kind of damage sounds familiar, that might be because you’ve already seen it on rhodies. The culprit can be any of several varieties of weevil that inhabits the nearby woods and does similar damage to salal and huckleberries. They can’t fly, but populations of them can slowly make their way over time from those native plants to your flower beds.
The damage you see right now probably happened during the late spring, summer or fall when adults emerge and start to feed. During the winter, adults remain inactive underground along side of the larvae, which nibble on tender roots. Around May, however, they’ll emerge from the soil at night like vampires, crawl up plant stems to chew on foliage, then return to hide below by sunrise.
If you don’t like what weevils are doing to your Bergenia – and possibly your rhodies – you can catch them, discourage them or kill them.
To catch them, head out with a flashlight in the middle of the night, put newspaper around the base of your plants and shake the leaves. Or pick them off. Or you can try putting pleated burlap or rolled up cardboard under the plants during the day and hope to catch some of the critters hiding there the next day.
You can try any number of sticky products around the stems to ensnare or discourage them. This would probably work better with rhodies than Bergenia, obviously. Just make sure the product you use doesn’t damage bark or other plant tissues. Coffee grounds are also said to discourage them. Just spread them around the base of your plants. The success of this may depend upon how addicted you are to caffeine and the amount of grounds you can rustle up.
Remember, anything that’s meant to keep weevils from climbing up the stems will easily be circumvented by foliage that’s allowed to droop and touch the ground or other climbable surfaces.
Finally, you can kill them. Read the label on any pesticide carefully and use it correctly. Never apply pesticides on flowers as it will kill your pollinators. Carefully apply it to all foliage surfaces and know it will kill any visiting beneficial insects along with the bad guys. Pesticides should always be your last resort.
Instead, try an application of beneficial nematodes as a counter attack against marauding weevils. Here again, make sure you follow the directions, not because nematodes can harm humans, but if applied in the sunlight or in too dry or too cold conditions they will all perish before they can do their job. And by the time you’ve gotten to this point in your battle, you’ll really want them to do their job.
