Vegetable gardens depend on healthy soil to flourish, while the presence of grubs can impede plant growth, leading to stunted or wilted foliage. They also attract foraging animals such as birds, skunks and raccoons who dig up your veggies in search of those tasty grubs!
Natural solutions may be more effective at keeping vegetable gardens free from grubs than chemical pesticides, such as heating the earth or using nematodes that infect grub worms.
Heat the Earth
Grubs can quickly destroy vegetable gardens, flowerbeds and natural grass lawns when there is an overabundance of them. Homeowners usually discover this issue during spring planting season when digging their flowerbeds to plant new bulbs or when noticing brown patches of turf in their lawn. Luckily there are several effective solutions available to homeowners for ridding themselves of grubs without resorting to toxic chemicals.
One method of killing grubs involves heating the soil. This technique, called soil solarization, involves covering affected areas with clear plastic for several weeks during the hottest part of summer until enough heat penetrates to kill grubs in the top few inches of soil, rendering it unfit for their young to thrive and make it unfit for survival. While this works effectively in vegetable gardens and flower beds, its effectiveness on grass lawns may vary as grubs can hide beneath its surface where treatment cannot reach them.
Another method of eliminating grubs is applying commercial microbial pesticide. Milky spore is an organic product available at most home and garden centers that targets Japanese beetle larval stage for quick killing. Multiple applications over several years will yield optimal results, though once established it should last up to 10 years!
Beneficial nematodes can also help to combat grub infestation. These microscopic roundworms infect and kill white grubs without harming plants or grass; you can find liquid or solid form at many home improvement and garden centers.
Frequent cultivation and tilling can reduce grub populations by killing adult beetles, killing their offspring, and disrupting feeding patterns. This approach works well in smaller gardens where beetles pose an occasional nuisance, although it won’t prevent future grub invasions when it comes time to reproduce.
Manual removal of grubs is often the best solution to their presence in vegetables and flowers, although it may take more time and requires wearing work gloves to protect yourself from their stinging juices.
Insecticidal Nematodes
If your vegetables appear stunted or dying, grub infestation may be to blame. Grub larvae live beneath the soil and feed off of roots of your plants, eating away at their roots until visible. They commonly affect lettuce, cabbage, broccoli and squash plants as examples.
There are various ways to rid the garden of grubs, including insecticidal soap or spray. However, these solutions should only be employed as last resort when other methods have failed.
Beneficial nematodes offer an alternative to chemical products for pest control: these tiny, parasitic creatures can be purchased from most home and garden centers and easily targeted at soil-dwelling pests like grubs. Although safe for children and pets alike, beneficial nematodes specifically target grubs for ultimate success in garden spaces.
Nematodes can help protect gardens against insects that threaten them by seeking out host insects and infiltrating their body cavities through natural openings used for breathing and digestion. Once inside an insect’s body cavities, nematodes release pathogenic bacteria which kill and dismember it internally before devouring it for food themselves and leaving behind more of their own to continue the cycle.
Beneficial nematodes should be applied throughout the year, but for maximum effect they should be introduced during spring or fall when most pests are in their larval stages. Organic fertilizer will reduce chances of harm to beneficial soil organisms.
Another effective method for killing grubs is with Bacillus thuringiensis bacteria, which also works as an insecticide and doesn’t harm other plants, beneficial insects or wildlife. When selecting your strain of Bt thuringiensis for European chafer control it is commonly labelled Bt galleriae.
Once introduced to your soil, bacteria quickly begins attacking grubs and other targeted pests, with Heterorhabditis-infected grubs turning orange-red while Steinernema-infected ones turning cream-colored or dark brown over time. If you want to see whether the solution is working effectively for you, dig up a few grubs from time to time and examine for signs of infection: infected Heterorhabditis ones will likely appear discolored while cream to dark brown ones will usually show signs of Heterorhabditis or Steinernema-infected ones appearing cream to dark brown when infected by infection; either way you’ll know it works in practice!
Bacillus thuringiensis
Grubs damage both vegetable plants and soil fertility. If you suspect an issue in your garden and see it struggling in summertime, check physically by gently lifting leaves or roots to check for them; once found they should be handpicked out by hand and disposed of. Work gloves should always be worn when dealing with grubs as their bite can sting or irritate hands; manual removal takes time and requires lots of patience but does not prevent further infestations.
Milky spore and Bacillus thuringiensis can help you eliminate grubs from your garden through biological methods. Both substances work by parasitizing them – entering their bodies to attack from within – before killing it from within. In order for milky spore to work effectively, however, you must apply it under specific circumstances: when feeding is active on soil. And to be most successful.
Beneficial nematodes, microscopic worms that target and parasitize grubs, are another option to control curl grub infestation. Nematodes such as Heterorhabditis bacteriophora and Steinernema riobrave specifically target curl grubs; you can purchase them from most home and garden centers or online. You should apply these nematodes when the grubs are small — typically in late summer or fall prior to dormant dormantification in preparation for winter dormantization.
Last resort would be using Bacillus thuringiensis (Bt), a bacterium which produces crystal proteins with insecticidal properties. Bt can be mixed with other organic insecticides or genetically modified crops like BT corn that resist European corn borer infestation. You can buy Bt from gardening stores and online and it should be applied when the grubs are small – usually spring or fall.
Although microbial pesticides can help control grub populations, cultural practices must also be employed. Overwatering creates the ideal environment for them; to keep grubs from reaching roots and killing them off it’s wiser to water deeply and infrequently instead.
Manual Removal
Beetle grubs can quickly decimate a vegetable garden when they attack. By devouring plant roots, these insects cause extensive damage in a short amount of time and must be eradicated as quickly as possible. There are both commercial chemicals and homemade remedies to kill them off; however, such treatments usually harm beneficial organisms in soil, making this option only suitable as a last resort.
Insecticidal nematodes are tiny worm-like creatures introduced into the soil that will search out and eliminate grubs in your garden. While they won’t harm any beneficial organisms or other creatures living there, you will need to apply multiple applications before their effectiveness becomes visible; you can find these at garden centers or online.
Milky Spore is another commercial microbial pesticide available to gardeners to control grubs in their gardens. Similar to nematodes, it infects grubs before killing them off; however, this method requires more costly spraying at two to three intervals over an extended period. To be effective.
Bacillus thuringiensis, or Bt, is another natural insecticide that is effective against grubs in your garden. A stomach poison specifically designed to target caterpillar larvae grubs but will not harm beneficial insects, birds, pets or humans, Bt can be purchased at gardening centers or online and mixed with water to create a spray that you will spray all around your yard.
Once you detect grubs in your garden, it is imperative that you act promptly. Otherwise, beetles will begin laying eggs that hatch as mature grubs feeding on vegetables in your garden. To prevent this from happening, kill any new grubs as soon as they appear using one of the methods above; make sure that you wear gloves while doing this as the grubs may hide under leaves and vegetables, stinging your skin when doing this job.