What is this weedy grass, redoing a strawberry bed and suggestions for potato bugs
In today's "Fielding Questions," columnist Don Kinzler says the key to potato bugs is rotation.
Q: What kind of grass or weed is this in our lawn? It’s by our driveway in front of our house. What can we use to curb it? — Roxane Eckroth, Wahpeton, N.D.
A: Wide-bladed, weedy grasses are sometimes all mistakenly called “crabgrass.” One way to differentiate is by seeing when they begin growth. Your photograph, taken now in early May, shows well-established grass plants, green and growing.
Actual crabgrass is an annual grass that restarts from seed each spring, that doesn’t germinate until soil temperatures are warm, meaning plants aren’t large and visible until sometime later in June.
Weedy grasses beginning strong growth in May are almost always perennial grasses like quackgrass, arising early from well-established, winter-hardy root systems. Other features identifying the grass as quackgrass are white underground rhizomes and "clasping auricles," which are tiny, fingerlike projections where the leaf blades attach to the stem.
Unfortunately, there isn't anything that will kill quackgrass without also killing the desirable lawn grass. You can spot-spray the patches of quackgrass with a grass-killing herbicide, such as glyphosate (original Roundup) and then reseed after the grass is dead-brown. Quackgrass often regrows from latent underground buds after the tops have died, so patiently allowing regrowth followed by a second spray is a more thorough method.
As an alternative to chemicals, quackgrass can be smothered with cardboard or black plastic held in place for most of the growing season and then reseed in September, if quackgrass has died.
When a scientist finds a marketable product that selectively kills quackgrass without harming the lawn, they will be heroes to lawn owners. And rich.
Q: We’re trying to thin out our strawberry patch. Should I remove the older, more established plants or the smaller, newer ones? Last year, our berries were small and I think it was because the plants are so close together. — Lucia Schroeder, Glyndon, Minn.
A: When renovating a strawberry bed, the newer plants are used, instead of the old.
Strawberry beds remain productive for about two or three seasons before plants become crowded and berry size declines. Then, healthy young plants can be dug and replanted at proper spacing in May.
Two planting systems can be used. The matted-row system is commonly used in home gardens. Rows are spaced 3 to 4 feet apart and plants are set 18 to 30 inches apart within the row. Allow runners to form a mat 15 to 18 inches wide, with plants 4 to 6 inches apart.
The second method, called the hill system, produces large, high-quality berries. Space rows 2 to 3 feet apart, with plants 12 to 15 inches apart within the row. Remove runners as they appear, so plants remain as individual “hills.”
Q: Do you have any suggestions for potato bugs? We’ve used various powders with no success. My grandfather once said the only sure cure for potato bugs is to take one at a time and put it between your thumb and pointer finger and squeeze it. Is that the only cure? — Jim and Judy Frisk.
A: Potato bugs are also known as Colorado potato beetles, which is often the name we find when searching insecticide labels.
Potato beetles have developed resistance to many common insecticides, which then give little or no control. The key is to rotate between several different chemicals including spinosad, permethrin, and Sevin. You might especially try spinosad, which is a relatively new insecticide and has been used with good results by many, as the beetles might not have developed as much resistance to it yet.
You mentioned hand-picking. That is still a legitimate method, walking the potato patch and picking larvae and beetles as you find them. My dad said that as a kid that was his job, and they would drop the beetles in a can of kerosene. Since many of us don't have kerosene on hand, drop them in a container of soapy water instead.
If you have a gardening or lawn care question, email Don Kinzler, NDSU Extension-Cass County, at email@example.com or call 701-241-5707. Questions with broad appeal may be published, so please include your name, city and state for appropriate advice.