One of the few plants that voles avoid is hellebore. Planting hellebores around other plants can help with their survival. JC Raulston Arboretum
One of the few plants that voles avoid is hellebore. Planting hellebores around other plants can help with their survival. JC Raulston Arboretum

Home & Garden

Ask the gardener: Hey, moles — leave these shrubs alone

By Mark Weathington

J.C. Raulston Arboretum

June 10, 2017 12:00 AM

Q: I have a mixed-shade yard under large oaks and have had troubles with moles. We try to keep the area covered in pine straw and want some color year-round to break up the brown. It’s a challenge for me to be able to grow anything the moles won’t kill. I don’t know how to get rid of the moles and I don’t know what else I can plant that they will leave alone. I’m looking for small evergreen ornamental shrubs. I’ve had pieris, azaleas, Japanese maples and wax myrtles all perish due to moles. Is there something that likes shade/part shade that the moles will ignore? My soil is basically very rocky clay, but I always embellish the soil when I plant anything new, which may be why it attracts the moles. -Christine Chase, Raleigh

A: I feel your pain. Moles can be a real problem but they aren’t after your plants – they are looking for insects and grubs to feed on. The holes they dig can cause your plants to die out. If roots or the tender bark at the base of your plants are being eaten, then you probably have voles. Both can be difficult to get rid of once they’re established. One of the few plants that voles avoid is hellebore. In fact I’ve found that planting hellebores around other plants can help with their survival. The best solution I’ve found for voles and moles is to mix sharp gravel in your planting beds. In one vole-infested garden I began mixing 1-2 heaping shovelfuls in with the soil every time we planted something new. I had great success with that method for voles and moles.

Q: I have a clivia and cannot get it to bloom. I have it indoors during the winter and outdoors in the summer. What is the secret to get it to bloom? -Diane Birkemo, Chapel Hill

A: A clivia in full bloom is truly a sight to behold but it does require some specialized care. You seem to be doing the first thing right – putting it outdoors in full sun for the summer. Fertilize it regularly during this time and bring your clivia in before frost or it can take significant damage. After you bring it in, stop watering it completely for about 3-4 months. While it is in this forced dry dormancy, it needs about five weeks of chilling where it stays above about 40 degrees but below 55 degrees. After it’s been through the chilling and dormancy, you can begin watering (start slowly) and raising the temperature. Clivia will generally flower in less than a month.

Q: I have 10, 30-foot-tall cypress trees that line the border of our back yard on both sides. Unfortunately one has died. Since they each were planted about 6 feet apart when we bought our house 20 years ago, there is blanket coverage between us and our neighbors. If I have the dead tree removed it will expose “non-foliated” branches of the adjacent tree. Will this removal place the existence of the adjacent tree (with exposed “naked” branches) in jeopardy and kill it as well? --Stephen Edwards, Bailey

A: The removal of your dead tree should not make your other trees more likely to die. If your first tree died due to a disease, the others could also be infected, though. But Leyland cypress trees will not put out new growth in those non-foliated areas, so keep that in mind. Your existing plants could also be somewhat more susceptible to being blown over by the wind.

Plant Spotlight

Common name: Bear’s foot hellebore

Botanical name: Helleborus foetidus

Family: Ranunculus (Ranunculaceae)

Category: Evergreen herbaceous perennial

Primary uses: Shade gardens, woodland gardens

Dimensions: 24 inches tall and wide

Culture: Shade. Bear’s foot hellebore is a tough evergreen plant for shade gardens. It will grow in a wide range of soils but is best in a loose soil. It can be quite drought tolerant once established. Bear’s foot hellebore will seed politely in the garden if the seeds are allowed to ripen and it can ultimately form a nice groundcover over time if allowed to self-sow. Cut the flowering stalks to the ground either after the seed has ripened if self-sowing is desired or before if not.

General attributes: Bear’s foot hellebore makes a showy plant for the shade garden with dark green leaves divided into narrow fingers. In winter, the stems are topped with large clusters of lime green, bell-shaped flowers. Hellebore roots are toxic so they are usually avoided by voles.