Small holes in your lawn are usually caused by a digging or burrowing creature. Before addressing the problem, first identify the cause. Holes can come from voles, bees, worms, or crawfish — and the solution depends on properly identifying the culprit.
Overview
In my experience identifying the cause of lawn holes, there are some specific questions you can ask yourself to help determine the cause. Unless catching the critter in the act, detective work is needed. Examine the holes closely and try to answer:
- Are there small dirt mounds elsewhere in the yard?
- Is it a solitary hole or connected to a tunnel or burrow?
- Is loose dirt around the hole or the edge clean?
- Is nearby grass damaged, chewed, shredded, or wilted?
- What is the size and shape — perfect circle or irregular?
Once gathering these clues, consult a reference guide to match holes to the likely cause. Handy resources include:
- Holes in the Lawn from Clemson University describes holes from various critters.
- The Internet Center for Wildlife Damage Management has an interactive search tool with photos to identify holes.
- This Wildlife Damage Control guide covers solutions for different animal damage.
Once the culprit is identified, targeted solutions can be found. Common causes of lawn holes and solutions include the following.
Moles
Moles create small, volcano-shaped dirt mounds tunneling below the surface. Tunnels are about 2 inches wide. Moles eat grubs and earthworms, damaging grass roots.
Control moles with kill traps like scissors or harpoons. Repellents with castor oil or capsaicin may also deter moles. Reduce their food source by using grub-killing nematodes.
Voles
Voles bore 1 to 2-inch wide burrows near the lawn surface. They eat grass roots causing dead brown patches. Burrows have clean, beveled edges and surface runways.
Trapping is most effective for voles. Poison baits are available but must be used carefully. Mowing your lawn short makes it less attractive to voles.
Crawfish
Crawfish dig 2-inch wide, 6 to 12-inch deep holes. Excavated dirt forms a mound around the hole. Crawfish eat plants, worms, and insects.
Spreading insecticide over infested areas can reduce populations. Encouraging natural predators like birds helps too. Carefully fill holes to avoid colony collapse.
Yellowjacket Wasps
Yellowjackets dig 1/2-inch wide holes to create underground nests. Nests often have multiple entrance holes in areas with abundant food and water. Watch for wasps flying in and out.
It’s best to call a pest control company to treat nests, as DIY methods can be risky.
Treatment involves applying insecticide dust or spray directly into the nest. Use insecticides carefully according to product instructions.
Cicada Killer Wasps
These large wasps dig 1/2-inch wide tunnels and insert cicadas as food for larvae. Holes go straight down and may have loose soil. Cicada killers rarely sting unless provoked.
Control is usually unnecessary since they do not damage turf. Mark and avoid nesting areas for safety. Dust insecticides can kill wasps if control is needed.
Ground-Nesting Bees
Solitary bees dig 1/4-inch wide holes straight down into soil. Some form dense colonies with many close holes — watch for bees entering and exiting holes during daylight.
It’s best to mow around and avoid ground bee nests. If control is needed, apply dust insecticides at night when bees are in nests. Remember, bees are important pollinators, so elimination should be a last resort.
Earthworms
Earthworms leave small piles around 1/4 to 1/2 inch holes from pushing castings up while feeding. This disrupts grass growth but improves soil health.
Reduce castings by avoiding over-fertilizing and irrigating which stimulates earthworms. Annually top dress lawns with compost to incorporate castings. Some insecticides also reduce populations.
Grubs
Beetle larvae called grubs feed on grass roots, weakening and damaging turf. Animals like raccoons dig random, shallow holes searching for grubs.
Apply beneficial nematodes or milky spores in summer to kill grubs. Avoid excess nitrogen fertilization encouraging grubs. Let grass grow longer to encourage predators. Filling animal holes and planting grub-resistant varieties helps.
Identifying Unique Damage
For holes not matching those above, look for other clues like hole size, shape, and location. Also, look for chewed plants, clipped leaves, dug-up bulbs, or pulled grass.
Unique damage may come from skunks, armadillos, rabbits, or ground squirrels. Once identified, solutions can target the specific pest. Call your County Extension Office if you are struggling to diagnose unusual damage.
When to Call a Professional
Severe infestations and dangerous pests like yellowjackets often require calling a professional pest control company. Though expensive, professionals have proper equipment and training to effectively and safely treat large nests that DIY methods may not solve.
Professionals can also diagnose mysterious damage, spotting clues a homeowner may miss. Treatment plans are then customized based on correctly identifying the pest.
Timing Control Efforts
Know when pests are most active and vulnerable. For example, late summer and early fall are best for treating grubs with nematodes. Spring is optimal for trapping burrowing rodents.
Identify holes as soon as you spot them within the same season they occur. This allows starting treatment before populations grow and damage worsens. A quick response also prevents spread to other lawn areas.
Preventing Holes
Proactive measures to avoid holes include:
- Adequately watering and judiciously fertilizing for turf health
- Allowing 3.5 inch tall grass
- Annually aerating to minimize thatch buildup
- Choosing grub-resistant grass varieties
- Installing physical barriers like wire mesh around beds
- Removing alternative food sources like fallen fruit and bird seed
- Sealing off access to dens and nests outside the lawn
- Trimming habitat like bushes and dense growth on fences
- Using preventative nematodes for grubs before root damage
While not always preventable, these steps can reduce the likelihood of burrowing pests invading your lawn.
So, Is Identifying Lawn Holes Important?
Yes, properly identifying holes in your lawn is an important first step before control attempts. Without accurate identification, ineffective treatment methods may be used or the problem made worse.
Diagnosing holes also prevents premature judgment. For example, while moles are pesky, they rarely cause severe damage and tunnels quickly collapse. Meanwhile, cicada killers look intimidating but do not harm the lawn.
Unaddressed holes can lead to dead grass, erosion, unsightliness, and potentially dangerous nests. Regularly walking the lawn makes early identification easier before damage escalates. If unable to diagnose the cause, do not hesitate to call an expert.
With accurate identification, solutions can then be tailored to efficiently resolve the issue. A successfully treated lawn will be more aesthetically pleasing, functional for recreation, and add value to the landscape.
FAQs About Lawn Holes
What are some common causes of holes in my lawn?
Common causes include moles, voles, crawfish, bees, wasps, earthworms, grubs, and animals like skunks or raccoons digging for grubs. Identifying the exact culprit is key before treatment.
How can I tell if I have moles or voles?
In my experience, I have noticed that moles leave volcano-like mounds and about 2 inch wide tunnels. Voles create 1-2 inch burrow openings with clean edges and surface runways. Voles also damage roots leaving dead patches.
What should I do about crawfish holes?
Spreading insecticide over heavily infested areas can reduce populations. Carefully fill holes to avoid colony collapse.
When should I call pest control for bee and wasp holes?
It is best to have professionals treat aggressive stinging insects. They have proper equipment and insecticides to eliminate nests, especially yellowjackets.
How can I reduce earthworm holes and castings?
Avoid over-fertilizing, which stimulates earthworms. Annual lawn aeration works castings into the soil. Minimizing irrigation also helps.
What is the best way to prevent future lawn holes?
Choose grub-resistant grass, allow taller mowing height, adequately water, minimize thatch buildup, properly use preventative nematodes and insecticides, eliminate nearby pest habitats, and install appropriate physical barriers.