Mulch xeric gardens with gravel
In the gardening Q-and-A column two weeks ago, you said rock may not be a good choice for flowerbeds. I have been doing a lot of reading about xeric gardening. I would really like to reduce the amount of water I use without giving up gardening.
The advice I read says to mulch xeric beds with gravel, which helps to capture water. Now I am confused. Can you help me sort this out?
Lisa Staub
Well, guess what? You and several other readers passed the pop quiz I hid in that column. For xeric landscapes, gravel mulches are appropriate because that is what is often found around these kinds of plants in the wild.
Xeric landscaping uses indigenous plants that tolerate your local climate easily. In our area of the country that often means they have to be drought resistant.
Another reason for rocks being part of a xeric landscape is that drought-tolerant plants often are succulent, and if too much water collects around the base of the plant, they will rot off at the soil line.
Rock mulches work fine in dry landscapes, but they don’t work as well in conventional garden settings.
Reader helps out
A reader questioned the photo of a spent rhododendron blossom combined with advice about not pruning it now. Good catch! There is a difference between deadheading and pruning.
Old blossoms can be deadheaded any time but preferably right after they finish blooming. It’s the branches and stems of the plant that are better pruned right after the plant finishes blooming, and not later.
Wireworms are pesky
I have always grown a beautiful garden on the rich Palouse soil. But this year my garden is infested with wireworms. They are killing my potatoes, beans and now the tomatoes.
What can I do to kill these wireworms and maybe salvage part of my garden, and what can I do to prevent them from coming back next year?
Cynthia Davis
I hate to be the bearer of bad news, but wireworms are very tough to control, if at all. These 1/4- to 3/4-inch long white to cream-colored worms are the larvae of the click beetle.
They live in the soil for three to six years feeding on small roots, tubers and stems. They overwinter one to two feet down in the soil.
For the home gardener there are no registered pesticides available to treat them. There are no biological controls beyond hoping a flock of birds shows up when you are turning the soil in the spring.
The only thing you can do is move the garden away from the area you have it now. But that is a big job.
I would dig around some of the plants that are just beginning to wilt and look for the small worms with six legs that some people say look like a millipedes to be sure, though, before you begin moving anything. Take anything you find and some plant samples to your local Master Gardeners for a definitive diagnisis.