Roundup may rid ivy of invasive neighbor

Q: Several years ago I planted six houttuynia plants at the bottom of a slope that also contained English ivy. Now the houttuynia is taller than the ivy and stinks like the dickens. Is there something I could spray on the houttuynia while it is taller than the ivy that would kill it but not ivy?

Rhonda Jobson, e-mail

A: Houttuynia, also known as chameleon plant, is a garden thug. Once planted, it is almost impossible to eradicate. But since it is taller than the ivy, you might find success by wiping glyphosate (Roundup, etc.) on its leaves using an old towel wrapped around the end of a garden rake.

Spray chemical on the towel until it is damp and then swipe it over the infested slope. Otherwise, no chemical is smart enough to tell the difference between chameleon plant and English ivy.

Q: I had a horrible time with squash vine borers this year. Will solarizing my soil this winter (clear plastic covering for 6-8 weeks) help eliminate the pupae for next year?

Susan Wheatley, Milton

A: Solarizing in winter won’t heat the soil enough to kill the overwintering larva. But you can do three things that will help control them: Till the soil in late December and again in February to destroy the larvae in their soil cocoons.

Apply insecticide (Sevin, etc.) to the stem of the plant from the time it begins to run until the first male flowers appear. Consider covering the young plants with floating row cover (Remay, etc.) up until female flowers begin to form.

Q: I usually aerate and overseed my fescue lawn in the fall. With the current watering restrictions, is this still something I can do?

Larry Riddle, e-mail

A: Current water regulations allow you to water every other day. But for best germination, fescue should be lightly watered every day.

That said, if you get really good seed-to-soil contact — by aerating thoroughly beforehand and dragging the lawn with carpet afterward to break up the aerator cores — you’ll likely get reasonable success.

Remember to get your watering permit at www.outdoorwateruse.com.

Q: My “Carissa” hollies have suckers coming off the roots. They look like Chinese holly leaves. I have cut them back but they keep sprouting back. What would you do?

John Sumlin, Atlanta

A: University of Georgia shrub expert Matthew Chappell says that “Carissa” originated from Chinese holly, Ilex cornuta. Most experts believe it came from a “sport”: an attractive sprout that appeared among the thorny leaves of a Chinese holly. The root sprouts on your “Carissa” have reverted back to its parent holly. To stop them, clip the sprouts close to the base and spray with Sucker Stopper (www.cooperseeds.com).