What are moles?
Moles are rarely seen as these mammals live mostly underground. They dig out a system of tunnels and chambers, and dispose of the excavated soil by throwing up molehills on the surface.
Moles don’t feed directly on plants. The damage they cause is incidental to their lifestyle. Molehills on lawns have to be removed before mowing and collapsed surface tunnels need filling in to maintain a level lawn surface.
Mole activity is usually greatest in late winter and early spring.
Several steps can be taken to control moles or encourage them to move elsewhere.
Mole traps for killing moles are inexpensive and available from garden centres and hardware stores.
- They are humane but need careful placement in a tunnel that is about 10-20cm (4–8in) below the surface, but not directly under a molehill
- The location of tunnels can be ascertained by scraping away a recent molehill and probing the hole with a pliable stick
- Open up a tunnel with the minimum of disturbance, using a hand trowel and carefully align the jaws of the trap with the direction and depth of the tunnel. No bait is required. Rub your hands and the trap with soil to disguise the human scent
- Once the trap is set, gently cover it with an upturned bucket to exclude light and draughts. Check the trap daily
- With a bit of luck, the mole will be caught but sometimes the mole pushes soil into the trap. If this happens, clear the tunnel of soil and reset the trap. If this continues to occur, reset the trap in a different part of the tunnel system
- Vacant tunnel systems may be taken over by another mole from nearby areas so further trapping may be needed to keep a garden mole free
Live-capture traps are also available for setting in mole tunnels. These need inspecting at least twice a day so that the mole can be released before it dies of starvation and/or stress. Captured moles should be released at least one mile away.
Electronic devices are more costly and available from garden centres and mail order firms. Their buzzing noise is said to drive moles away; however this may only be to another part of the garden.
A type of mole-repellent smoke, sold as Pest-Stop Biofume Mole Smoke, emits castor oil fumes. These are said to line the tunnels and deter worms and other mole food from entering the tunnels. The hungry mole will then move elsewhere, or it may simply create new tunnels nearby.
Caper spurge, Euphorbia lathyris, which is a biennial plant, has its adherents who claim the root exudates repel moles. It is worth a try, but remove most of the flower heads before seeding occurs or a weed problem may result. Bulbs of Allium moly are also sold as a mole deterrent but are of doubtful value.
Hire a professional
Mole smokes for killing moles are no longer on sale to home gardeners. Professional contractors can be employed to use pellets that emit toxic gases into the tunnel system, but these cannot be used within 3m (10ft) of occupied buildings. These pellets can be effective but freedom from moles may not last long if there are other infested areas nearby from which moles can soon recolonise the garden.
Live moles are rarely seen above ground. They are about 15cm (6in) long, with dense blackish-brown fur and broad front paws that are adapted for digging.
The main breeding season runs from February to June, and a female will have three or four young in a nest built underground. Outside the breeding season, moles lead largely solitary lives, so all the mole activity in a small garden could be due to a single animal.
Moles feed on earthworms and other soil-dwelling creatures, not on plant roots.
Image: © GWI/Nicholas Appleby. Available in high resolution at www.gardenworldimages.com