Home and garden Q&A: Controlling caterpillars, ivy

Published 12:00 am Sunday, April 12, 2020

Many are working outdoors in our beautiful spring weather while homebound. Retail garden shops and outlets are bustling with those choosing to take advantage of their time and weather. Below are questions posed to me as I was wondering though one of our local garden shops.

Question: I think I have bagworms in my cherry tree? They’re ugly and making a mess. How do I control them?

Answer: Those are not bagworms but tent caterpillars. The annual spring infestation time often varies, but it looks like they’re early this year and a heavy number. Control by disturbing the nest with a stick, opening the caterpillars to birds and other prey. Bacillus thuringenisis sprays (Dipel, BT’s) will also control them.

Question: When is the best time to mow my daffodil foliage? They have bloomed out and starting to look bad.

Answer: Leave the foliage intact as long as possible. The foliage eventually turns brown and then it can be removed without damage to the bulbs. It is important to leave the foliage as long as possible as it provides a source of food to produce next year’s flower.

Question: What’s the best way to control English ivy? It’s growing all over my yard and now it’s starting to climb into my trees.

Answer: Physical removal is most effective control measure if practical. Vines that can be mowed can be controlled with constant mowing. Utilize a sharp pair of pruners or loppers and cut large vines at a reasonable height. The upper portion of the vines will eventually die. It often takes many months for the vines to eventually die. The dying plants will look unsightly for a few months. Don’t use a string trimmer around trees to cut the ivy away from the trees.

The cut ivy stumps should immediately be painted with an undiluted brush killer (triclopyr) or glyphosate (Roundup). Use a paint brush applying the herbicide directly from the container on the freshly cut stumps. The herbicides translocate through the vascular system into the root system controlling the vine growth. You must be persistent to control this weed.

Question: Can I use ground cloth to control weeds around may shrub beds? I have a lot of weeds during the early spring and I need to find a way to control them.

Answer: Using ground cloth is one of those “maybe” answers. For some locations, ground cloth is fine for a few years controlling weeds. Other locations with Bermuda grass and other weeds it can be a nightmare. It works well under ornamental pebbles and stones. I suggest a preemergence herbicide in fall and spring to control weeds. Perennial weeds such as Bermuda grass is very difficult.

Darrell Blackwelder deblackw@ncsu.edu is the retired horticulture agent and director with the North Carolina Cooperative Extension Service in Rowan County.