Killer beetles and mystery weeds: Your garden questions answered
QUESTION 1: What are these Beetle-like bugs? Are they killing my climbing hydrangeas? - Sandi, in St. Thomas
MARJORIE'S ANSWER: This is the Japanese beetle. I’m afraid you are in for some serious handpicking of this wicked creature. There has been such an infestation of them that they can skeletonize a plant in very short order. They didn’t get bumped off in the cold of last winter so we have more than usual this year. This is not a personal attack on your climbing hydrangea—it was probably just something very handy to chew on.
MARJORIE’S ANSWER CONT’D: There are pheromone traps which draw them in and make them easy to kill but you also get every other beetle around. Make a wash of Neem oil (sold as Plant Polish) and soak the soil around the plant. Buy Neem Oil which is and read the instructions carefully. Take a pail of soapy water and knock them into it. They like to eat in groups (ergo easy skeletonizing) so you can start knocking them off the plant top to bottom. * You can use insecticidal soap (1tsp of soap in a pint of water with a dab of oil to make it adhere) but you’ve got to hit them directly.
QUESTION 2: How to we control Campanula that's invaded our lawn? Repeated pulling of the leaves, attempts at digging out the stolons, herbicide and willfully ignoring it just don't get rid of it! It's also in the annual bed adjoining the lawn, but isn't so much of a distraction. What to do? Yours, Lester Young, Saskatoon
MARJORIE’S ANSWER: Campanula rapunculoides is one those siren-like dangerous invaders. Once it’s in place, it will invade root systems all around it strangling them in the process. Don’t try to pull it out, dig it out. Like many of the exotic aliens, it has a brittle root system. Among the annuals, lift all the plants and sniggle it out carefully before you re-plant the annuals.
MARJORIE’S ANSWER CONT’D: Any little bits and bobs left behind will start a new plant and be vigorous before you can possible imagine. Keep at it, eventually you will prevail. But, if your neighbours let it grow to flowering, it will also seed about. Ask them to cut off the flowers before this happens. A touch of vinegar on the leaves might help as well kill them off systemically.
QUESTION 3: We moved into our home last summer and had a large lilac removed to build a new fence. The lawn was already a mess of clover, a flowering purple weed and a leafy weed that is taking over our entire lawn and the old lilac dirt patch is now entirely weeds. With more weeds than grass is there any point to having a lawn company to do a few treatments to get it under control or should we start from scratch? We don't require a large, perfect lawn and want to avoid chemicals. - Lesley, Winnipeg, MB
MARJORIE’S ANSWER: You’ve probably stirred up weeds that had been lying dormant for years and years. This looks like the first year of a biennial called Garlic Mustard. This stuff ramps around the first year and the next year it will have a nice long neck with a white flower. It’s awful stuff. You can cover some of the worst infested areas by smothering them with thick layers of newspapers and kill them off that way. It would extend your border and the newspaper composts down (especially when you have a layer of manure or compost covering it). Then re-seed the area.
MARJORIE’S ANSWER CONT’D: For the infestation in your border, you are going to have to pull them out by hand. BUT you’ve got to get the all the roots, these plants go everywhere by seed. It’s astounding how fast it will establish a colony when it’s not kept under control. Don’t use chemicals, pay every kid in the neighbourhood to come in and do some weeding. Dig them up where you can being careful not to leave anything in the soil.
QUESTION 4: My neighbour's yard is overrun with horsetail. She tries to dig it up, which only exacerbates the problem. A shared gravel driveway separates the two yards and her side is filling up with it too. How can I keep my gardens a meter away from becoming infested? Help! - Geri Openshaw, North Bay, Ontario
MARJORIE’S ANSWER: Horsetail is likely to be taking over your garden very soon. It’s going to take a metal barrier but much easier is pouring boiling hot water on what’s growing n the the gravel driveway. Get a long outdoor cord, an electric kettle and pour boiling water on the gravel areas. This is safe because you won’t be killing off the good stuff.
MARJORIE’S ANSWER CONT’D: Tell your neighbour to stop pulling at these weeds - it just encourages them. If it’s covering most of her garden, cut back to the level of the soil. Cover with plastic and hold the edges down with stones or bricks and keep it in this state to fry these wretched weeks. You might try a spray on then: cut them back to the level of the soil, then spray with vinegar (cheap white stuff but look for horticultural vinegar as well). Put a tsp of vinegar in a pint of water.